Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-30 (of 115 Records) |
Query Trace: Pallansch M[original query] |
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Clinical and laboratory findings of the first imported case of Middle East respiratory syndrome coronavirus to the United States.
Kapoor M , Pringle K , Kumar A , Dearth S , Liu L , Lovchik J , Perez O , Pontones P , Richards S , Yeadon-Fagbohun J , Breakwell L , Chea N , Cohen NJ , Schneider E , Erdman D , Haynes L , Pallansch M , Tao Y , Tong S , Gerber S , Swerdlow D , Feikin DR . Clin Infect Dis 2014 59 (11) 1511-8 BACKGROUND: The Middle East respiratory syndrome coronavirus (MERS-CoV) was discovered September 2012 in the Kingdom of Saudi Arabia (KSA). The first US case of MERS-CoV was confirmed on 2 May 2014. METHODS: We summarize the clinical symptoms and signs, laboratory and radiologic findings, and MERS-CoV-specific tests. RESULTS: The patient is a 65-year-old physician who worked in a hospital in KSA where MERS-CoV patients were treated. His illness onset included malaise, myalgias, and low-grade fever. He flew to the United States on day of illness (DOI) 7. His first respiratory symptom, a dry cough, developed on DOI 10. On DOI 11, he presented to an Indiana hospital as dyspneic, hypoxic, and with a right lower lobe infiltrate on chest radiography. On DOI 12, his serum tested positive by real-time reverse transcription polymerase chain reaction (rRT-PCR) for MERS-CoV and showed high MERS-CoV antibody titers, whereas his nasopharyngeal swab was rRT-PCR negative. Expectorated sputum was rRT-PCR positive the following day, with a high viral load (5.31 × 10(6) copies/mL). He was treated with antibiotics, intravenous immunoglobulin, and oxygen by nasal cannula. He was discharged on DOI 22. The genome sequence was similar (>99%) to other known MERS-CoV sequences, clustering with those from KSA from June to July 2013. CONCLUSIONS: This patient had a prolonged nonspecific prodromal illness before developing respiratory symptoms. Both sera and sputum were rRT-PCR positive when nasopharyngeal specimens were negative. US clinicians must be vigilant for MERS-CoV in patients with febrile and/or respiratory illness with recent travel to the Arabian Peninsula, especially among healthcare workers. |
Poliovirus type 1 systemic humoral and intestinal mucosal immunity induced by monovalent oral poliovirus vaccine, fractional inactivated poliovirus vaccine, and bivalent oral poliovirus vaccine: A randomized controlled trial
Snider CJ , Zaman K , Wilkinson AL , Binte Aziz A , Yunus M , Haque W , Jones KAV , Wei L , Estivariz CF , Konopka-Anstadt JL , Mainou BA , Patel JC , Lickness JS , Pallansch MA , Wassilak SGF , Steven Oberste M , Anand A . Vaccine 2023 41 (41) 6083-6092 BACKGROUND: To inform response strategies, we examined type 1 humoral and intestinal immunity induced by 1) one fractional inactivated poliovirus vaccine (fIPV) dose given with monovalent oral poliovirus vaccine (mOPV1), and 2) mOPV1 versus bivalent OPV (bOPV). METHODS: We conducted a randomized, controlled, open-label trial in Dhaka, Bangladesh. Healthy infants aged 5 weeks were block randomized to one of four arms: mOPV1 at age 6-10-14 weeks/fIPV at 6 weeks (A); mOPV1 at 6-10-14 weeks/fIPV at 10 weeks (B); mOPV1 at 6-10-14 weeks (C); and bOPV at 6-10-14 weeks (D). Immune response at 10 weeks and cumulative response at 14 weeks was assessed among the modified intention-to-treat population, defined as seroconversion from seronegative (<1:8 titers) to seropositive (≥1:8) or a four-fold titer rise among seropositive participants sustained to age 18 weeks. We examined virus shedding after two doses of mOPV1 with and without fIPV, and after the first mOPV1 or bOPV dose. The trial is registered at ClinicalTrials.gov (NCT03722004). FINDINGS: During 18 December 2018 - 23 November 2019, 1,192 infants were enrolled (arms A:301; B:295; C:298; D:298). Immune responses at 14 weeks did not differ after two mOPV1 doses alone (94% [95% CI: 91-97%]) versus two mOPV1 doses with fIPV at 6 weeks (96% [93-98%]) or 10 weeks (96% [93-98%]). Participants who received mOPV1 and fIPV at 10 weeks had significantly lower shedding (p < 0·001) one- and two-weeks later compared with mOPV1 alone. Response to one mOPV1 dose was significantly higher than one bOPV dose (79% versus 67%; p < 0·001) and shedding two-weeks later was significantly higher after mOPV1 (76% versus 56%; p < 0·001) indicating improved vaccine replication. Ninety-nine adverse events were reported, 29 serious including two deaths; none were attributed to study vaccines. INTERPRETATION: Given with the second mOPV1 dose, fIPV improved intestinal immunity but not humoral immunity. One mOPV1 dose induced higher humoral and intestinal immunity than bOPV. FUNDING: U.S. Centers for Disease Control and Prevention. |
Coordinated global cessation of oral poliovirus vaccine use: Options and potential consequences
Kalkowska DA , Wassilak SGF , Wiesen E , Burns CC , Pallansch MA , Badizadegan K , Thompson KM . Risk Anal 2023 Due to the very low, but nonzero, paralysis risks associated with the use of oral poliovirus vaccine (OPV), eradicating poliomyelitis requires ending all OPV use globally. The Global Polio Eradication Initiative (GPEI) coordinated cessation of Sabin type 2 OPV (OPV2 cessation) in 2016, except for emergency outbreak response. However, as of early 2023, plans for cessation of bivalent OPV (bOPV, containing types 1 and 3 OPV) remain undefined, and OPV2 use for outbreak response continues due to ongoing transmission of type 2 polioviruses and reported type 2 cases. Recent development and use of a genetically stabilized novel type 2 OPV (nOPV2) leads to additional potential vaccine options and increasing complexity in strategies for the polio endgame. Prior applications of integrated global risk, economic, and poliovirus transmission modeling consistent with GPEI strategic plans that preceded OPV2 cessation explored OPV cessation dynamics and the evaluation of options to support globally coordinated risk management efforts. The 2022-2026 GPEI strategic plan highlighted the need for early bOPV cessation planning. We review the published modeling and explore bOPV cessation immunization options as of 2022, assuming that the GPEI partners will not support restart of the use of any OPV type in routine immunization after a globally coordinated cessation of such use. We model the potential consequences of globally coordinating bOPV cessation in 2027, as anticipated in the 2022-2026 GPEI strategic plan. We do not find any options for bOPV cessation likely to succeed without a strategy of bOPV intensification to increase population immunity prior to cessation. |
Worst-case scenarios: Modeling uncontrolled type 2 polio transmission
Kalkowska DA , Wiesen E , Wassilak SGF , Burns CC , Pallansch MA , Badizadegan K , Thompson KM . Risk Anal 2023 In May 2016, the Global Polio Eradication Initiative (GPEI) coordinated the cessation of all use of type 2 oral poliovirus vaccine (OPV2), except for emergency outbreak response. Since then, paralytic polio cases caused by type 2 vaccine-derived polioviruses now exceed 3,000 cases reported by 39 countries. In 2022 (as of April 25, 2023), 20 countries reported detection of cases and nine other countries reported environmental surveillance detection, but no reported cases. Recent development of a genetically modified novel type 2 OPV (nOPV2) may help curb the generation of neurovirulent vaccine-derived strains; its use since 2021 under Emergency Use Listing is limited to outbreak response activities. Prior modeling studies showed that the expected trajectory for global type 2 viruses does not appear headed toward eradication, even with the best possible properties of nOPV2 assuming current outbreak response performance. Continued persistence of type 2 poliovirus transmission exposes the world to the risks of potentially high-consequence events such as the importation of virus into high-transmission areas of India or Bangladesh. Building on prior polio endgame modeling and assuming current national and GPEI outbreak response performance, we show no probability of successfully eradicating type 2 polioviruses in the near term regardless of vaccine choice. We also demonstrate the possible worst-case scenarios could result in rapid expansion of paralytic cases and preclude the goal of permanently ending all cases of poliomyelitis in the foreseeable future. Avoiding such catastrophic scenarios will depend on the development of strategies that raise population immunity to type 2 polioviruses. |
Immunogenicity of novel oral poliovirus vaccine type 2 administered concomitantly with bivalent oral poliovirus vaccine: an open-label, non-inferiority, randomised, controlled trial
Wilkinson AL , Zaman K , Hoque M , Estivariz CF , Burns CC , Konopka-Anstadt JL , Mainou BA , Kovacs SD , An Q , Lickness JS , Yunus M , Snider CJ , Zhang Y , Coffee E , Abid T , Wassilak SGF , Pallansch MA , Oberste MS , Vertefeuille JF , Anand A . Lancet Infect Dis 2023 23 (9) 1062-1071 BACKGROUND: Novel oral poliovirus vaccine type 2 (nOPV2) was developed by modifying the Sabin strain to increase genetic stability and reduce risk of seeding new circulating vaccine-derived poliovirus type 2 outbreaks. Bivalent oral poliovirus vaccine (bOPV; containing Sabin types 1 and 3) is the vaccine of choice for type 1 and type 3 outbreak responses. We aimed to assess immunological interference between nOPV2 and bOPV when administered concomitantly. METHODS: We conducted an open-label, non-inferiority, randomised, controlled trial at two clinical trial sites in Dhaka, Bangladesh. Healthy infants aged 6 weeks were randomly assigned (1:1:1) using block randomisation, stratified by site, to receive nOPV2 only, nOPV2 plus bOPV, or bOPV only, at the ages of 6 weeks, 10 weeks, and 14 weeks. Eligibility criteria included singleton and full term (≥37 weeks' gestation) birth and parents intending to remain in the study area for the duration of study follow-up activities. Poliovirus neutralising antibody titres were measured at the ages of 6 weeks, 10 weeks, 14 weeks, and 18 weeks. The primary outcome was cumulative immune response for all three poliovirus types at the age of 14 weeks (after two doses) and was assessed in the modified intention-to-treat population, which was restricted to participants with adequate blood specimens from all study visits. Safety was assessed in all participants who received at least one dose of study product. A non-inferiority margin of 10% was used to compare single and concomitant administration. This trial is registered with ClinicalTrials.gov, NCT04579510. FINDINGS: Between Feb 8 and Sept 26, 2021, 736 participants (244 in the nOPV2 only group, 246 in the nOPV2 plus bOPV group, and 246 in the bOPV only group) were enrolled and included in the modified intention-to-treat analysis. After two doses, 209 (86%; 95% CI 81-90) participants in the nOPV2 only group and 159 (65%; 58-70) participants in the nOPV2 plus bOPV group had a type 2 poliovirus immune response; 227 (92%; 88-95) participants in the nOPV2 plus bOPV group and 229 (93%; 89-96) participants in the bOPV only group had a type 1 response; and 216 (88%; 83-91) participants in the nOPV2 plus bOPV group and 212 (86%; 81-90) participants in the bOPV only group had a type 3 response. Co-administration was non-inferior to single administration for types 1 and 3, but not for type 2. There were 15 serious adverse events (including three deaths, one in each group, all attributable to sudden infant death syndrome); none were attributed to vaccination. INTERPRETATION: Co-administration of nOPV2 and bOPV interfered with immunogenicity for poliovirus type 2, but not for types 1 and 3. The blunted nOPV2 immunogenicity we observed would be a major drawback of using co-administration as a vaccination strategy. FUNDING: The US Centers for Disease Control and Prevention. |
Certifying the interruption of wild poliovirus transmission in the WHO African region on the turbulent journey to a polio-free world
Africa Regional Commission for the Certification of Poliomyelitis Eradication , Leke Rose Gana Fomban , Kaboré B Jean , King Arlene , Pallansch Mark A , Tomori Oyewale , Jack Abdoulie D , Sadrizadeh Bijan , Kane Ibrahima , Kironde Naddumba Edward , Lopes-Feio Raul Jorge , Chunsuttiwat Supamit , Maiga Zakaria , Kouassi Beugré , Khomo Ngokoana Esther , Tangermann Rudolf H , Matuja William Bahati Pungu , Mkanda Pascal . Lancet Glob Health 2020 8 (10) e1345-e1351 On Aug 25 2020, the Africa Regional Commission for the Certification of Poliomyelitis Eradication declared that the WHO African region had interrupted transmission of all indigenous wild polioviruses. This declaration marks the African region as the fifth of the six WHO regions to celebrate this extraordinary achievement. Following the Yaoundé Declaration on Polio Eradication in Africa by heads of state and governments in 1996, Nelson Mandela launched the Kick Polio out of Africa campaign. In this Health Policy paper, we describe the long and turbulent journey to the certification of the interruption of wild poliovirus transmission, focusing on 2016-20, lessons learned, and the strategies and analyses that convinced the Regional Commission that the African region is free of wild polioviruses. This certification of the WHO African region shows the feasibility of polio eradication in countries with chronic insecurity, inaccessible and hard-to-reach populations, and weak health systems. Challenges have been daunting and the sacrifices enormous-dozens of health workers and volunteers have lost their lives in the pursuit of a polio-free Africa. |
Initial public health response and interim clinical guidance for the 2019 novel coronavirus outbreak - United States, December 31, 2019-February 4, 2020.
Patel A , Jernigan DB , 2019-nCOV CDC Response Team , Abdirizak Fatuma , Abedi Glen , Aggarwal Sharad , Albina Denise , Allen Elizabeth , Andersen Lauren , Anderson Jade , Anderson Megan , Anderson Tara , Anderson Kayla , Bardossy Ana Cecilia , Barry Vaughn , Beer Karlyn , Bell Michael , Berger Sherri , Bertulfo Joseph , Biggs Holly , Bornemann Jennifer , Bornstein Josh , Bower Willie , Bresee Joseph , Brown Clive , Budd Alicia , Buigut Jennifer , Burke Stephen , Burke Rachel , Burns Erin , Butler Jay , Cantrell Russell , Cardemil Cristina , Cates Jordan , Cetron Marty , Chatham-Stephens Kevin , Chatham-Stevens Kevin , Chea Nora , Christensen Bryan , Chu Victoria , Clarke Kevin , Cleveland Angela , Cohen Nicole , Cohen Max , Cohn Amanda , Collins Jennifer , Conners Erin , Curns Aaron , Dahl Rebecca , Daley Walter , Dasari Vishal , Davlantes Elizabeth , Dawson Patrick , Delaney Lisa , Donahue Matthew , Dowell Chad , Dyal Jonathan , Edens William , Eidex Rachel , Epstein Lauren , Evans Mary , Fagan Ryan , Farris Kevin , Feldstein Leora , Fox LeAnne , Frank Mark , Freeman Brandi , Fry Alicia , Fuller James , Galang Romeo , Gerber Sue , Gokhale Runa , Goldstein Sue , Gorman Sue , Gregg William , Greim William , Grube Steven , Hall Aron , Haynes Amber , Hill Sherrasa , Hornsby-Myers Jennifer , Hunter Jennifer , Ionta Christopher , Isenhour Cheryl , Jacobs Max , Jacobs Slifka Kara , Jernigan Daniel , Jhung Michael , Jones-Wormley Jamie , Kambhampati Anita , Kamili Shifaq , Kennedy Pamela , Kent Charlotte , Killerby Marie , Kim Lindsay , Kirking Hannah , Koonin Lisa , Koppaka Ram , Kosmos Christine , Kuhar David , Kuhnert-Tallman Wendi , Kujawski Stephanie , Kumar Archana , Landon Alexander , Lee Leslie , Leung Jessica , Lindstrom Stephen , Link-Gelles Ruth , Lively Joana , Lu Xiaoyan , Lynch Brian , Malapati Lakshmi , Mandel Samantha , Manns Brian , Marano Nina , Marlow Mariel , Marston Barbara , McClung Nancy , McClure Liz , McDonald Emily , McGovern Oliva , Messonnier Nancy , Midgley Claire , Moulia Danielle , Murray Janna , Noelte Kate , Noonan-Smith Michelle , Nordlund Kristen , Norton Emily , Oliver Sara , Pallansch Mark , Parashar Umesh , Patel Anita , Patel Manisha , Pettrone Kristen , Pierce Taran , Pietz Harald , Pillai Satish , Radonovich Lewis , Reagan-Steiner Sarah , Reel Amy , Reese Heather , Rha Brian , Ricks Philip , Rolfes Melissa , Roohi Shahrokh , Roper Lauren , Rotz Lisa , Routh Janell , Sakthivel Senthil Kumar Sarmiento Luisa , Schindelar Jessica , Schneider Eileen , Schuchat Anne , Scott Sarah , Shetty Varun , Shockey Caitlin , Shugart Jill , Stenger Mark , Stuckey Matthew , Sunshine Brittany , Sykes Tamara , Trapp Jonathan , Uyeki Timothy , Vahey Grace , Valderrama Amy , Villanueva Julie , Walker Tunicia , Wallace Megan , Wang Lijuan , Watson John , Weber Angie , Weinbaum Cindy , Weldon William , Westnedge Caroline , Whitaker Brett , Whitaker Michael , Williams Alcia , Williams Holly , Willams Ian , Wong Karen , Xie Amy , Yousef Anna . Am J Transplant 2020 20 (3) 889-895 This article summarizes what is currently known about the 2019 novel coronavirus and offers interim guidance. |
Assessing country compliance with circulating vaccine-derived poliovirus type 2 outbreak response standard operating procedures: April 2016 to December 2020
Darwar R , Biya O , Greene SA , Jorba J , Al Safadi M , Franka R , Wiesen E , Durry E , Pallansch MA . Vaccine 2023 41 Suppl 1 A25-A34 BACKGROUND: Trivalent oral poliovirus vaccine (tOPV) was globally replaced with bivalent oral poliovirus vaccine (bOPV) in April 2016 ("the switch"). Many outbreaks of paralytic poliomyelitis associated with type 2 circulating vaccine-derived poliovirus (cVDPV2) have been reported since this time. The Global Polio Eradication Initiative (GPEI) developed standard operating procedures (SOPs) to guide countries experiencing cVDPV2 outbreaks to implement timely and effective outbreak response (OBR). To assess the possible role of compliance with SOPs in successfully stopping cVDPV2 outbreaks, we analyzed data on critical timelines in the OBR process. METHODS: Data were collected on all cVDPV2 outbreaks detected for the period April 1, 2016 and December 31, 2020 and all outbreak responses to those outbreaks between April 1, 2016 and December 31, 2021. We conducted secondary data analysis using the GPEI Polio Information System database, records from the Anonymized Institution Poliovirus Laboratory, and meeting minutes of the monovalent OPV2 (mOPV2) Advisory Group. Date of notification of circulating virus was defined as Day 0 for this analysis. Extracted process variables were compared with indicators in the GPEI SOP version 3.1. RESULTS: One hundred and eleven cVDPV2 outbreaks resulting from 67 distinct cVDPV2 emergences were reported during April 1, 2016-December 31, 2020, affecting 34 countries across four World Health Organization Regions. Out of 65 OBRs with the first large-scale campaign (R1) conducted after Day 0, only 12 (18.5%) R1s were conducted by the target of 28 days after Day 0. Of the 89 OBRs with the second large-scale campaign (R2) conducted after Day 0, 30 (33.7%) R2s were conducted by the target of 56 days after Day 0. Twenty-three (31.9%) of the 72 outbreaks with isolates dated after Day 0 were stopped within the 120-day target. CONCLUSION: Since "the switch", delays in OBR implementation were evident in many countries, which may be related to the persistence of cVDPV2 outbreaks >120 days. To achieve timely and effective response, countries should follow GPEI OBR guidelines. |
Outbreak response strategies with type 2-containing oral poliovirus vaccines
Kalkowska DA , Wassilak SGF , Pallansch MA , Burns CC , Wiesen E , Durry E , Badizadegan K , Thompson KM . Vaccine 2022 41 Suppl 1 A142-A152 Despite exhaustive and fully-financed plans to manage the risks of globally coordinated cessation of oral poliovirus vaccine (OPV) containing type 2 (OPV2) prior to 2016, as of 2022, extensive, continued transmission of circulating vaccine-derived polioviruses (cVDPVs) type 2 (cVDPV2) remains. Notably, cumulative cases caused by cVDPV2 since 2016 now exceed 2,500. Earlier analyses explored the implications of using different vaccine formulations to respond to cVDPV2 outbreaks and demonstrated how different properties of novel OPV2 (nOPV2) might affect its performance compared to Sabin monovalent OPV2 (mOPV2). These prior analyses used fixed assumptions for how outbreak response would occur, but outbreak response implementation can change. We update an existing global poliovirus transmission model to explore different options for responding with different vaccines and assumptions about scope, delays, immunization intensity, target age groups, and number of rounds. Our findings suggest that in order to successfully stop all cVDPV2 transmission globally, countries and the Global Polio Eradication Initiative need to address the deficiencies in emergency outbreak response policy and implementation. The polio program must urgently act to substantially reduce response time, target larger populations - particularly in high transmission areas - and achieve high coverage with improved access to under-vaccinated subpopulations. Given the limited supplies of nOPV2 at the present, using mOPV2 intensively immediately, followed by nOPV2 intensively if needed and when sufficient quantities become available, substantially increases the probability of ending cVDPV2 transmission globally. |
Circulating Poliovirus in New York - New Instance of an Old Problem.
Pallansch Mark A. The New England journal of medicine 2022 387(19) 1725-1728 . The New England journal of medicine 2022 387(19) 1725-1728 Pallansch Mark A. The New England journal of medicine 2022 387(19) 1725-1728 |
Global oral poliovirus vaccine stockpile management as an essential preparedness and response mechanism for type 2 poliovirus outbreaks following global oral poliovirus vaccine type 2 withdrawal.
Harutyunyan V , Quddus A , Pallansch M , Zipursky S , Woods D , Ottosen A , Vertefeuille J , Lewis I . Vaccine 2022 41 Suppl 1 A70-A78 Following the global declaration of indigenous wild poliovirus type 2 eradication in 2015, the world switched to oral polio vaccine (OPV) that removed the type 2 component. This 'switch' included the widespread introduction of inactivated poliovirus vaccine and the creation of a stockpile of monovalent type 2 OPV (mOPV2) to respond to potential polio virus Type 2 (PV2) outbreaks and events. With subsequent detection of outbreaks of circulating vaccine-derived poliovirus type 2 (cVDPV2), it was necessary to use this stockpile for outbreak response. Not only were more outbreaks detected than anticipated in the first few years after the switch, but the number of supplemental immunization activities (SIAs) used to stop transmission was often high, and in many cases did not stop wider transmission. Use of mOPV type 2 led in some locations to the emergence of new outbreaks that required further use of the vaccine from the stockpile. In the following years, stockpile management became a critical element of the cVDPV2 outbreak response strategy and continued to evolve to include trivalent OPV and genetically stabilized 'novel OPV type 2' vaccines in the stockpile. An overview of this process and its evolution is presented to highlight several of these management challenges. The unpredictable vaccine demand, fixed production and procurement timelines, resource requirements, and multiple vaccine types contributes to the complexity of assuring appropriate vaccine availability for this critical programmatic need to stop outbreaks. |
Assessing the immunogenicity of three different inactivated polio vaccine schedules for use after oral polio vaccine cessation, an open label, phase IV, randomized controlled trial
Zaman K , Kovacs SD , Vanderende K , Aziz A , Yunus M , Khan S , Snider CJ , An Q , Estivariz CF , Oberste MS , Pallansch MA , Anand A . Vaccine 2021 39 (40) 5814-5821 BACKGROUND: After global oral poliovirus vaccine (OPV) cessation, the Strategic Advisory Group of Experts on Immunization (SAGE) currently recommends a two-dose schedule of inactivated poliovirus vaccine (IPV) beginning ≥14-weeks of age to achieve at least 90% immune response. We aimed to compare the immunogenicity of three different two-dose IPV schedules started before or at 14-weeks of age. METHODS: We conducted a randomized, controlled, open-label, inequality trial at two sites in Dhaka, Bangladesh. Healthy infants at 6-weeks of age were randomized into one of five arms to receive two-dose IPV schedules at different ages with and without OPV. The three IPV-only arms are presented: Arm C received IPV at 14-weeks and 9-months; Arm D received IPV at 6-weeks and 9-months; and Arm E received IPV at 6 and 14-weeks. The primary outcome was immune response defined as seroconversion from seronegative (<1:8) to seropositive (≥1:8) after vaccination, or a four-fold rise in antibody titers and median reciprocal antibody titers to all three poliovirus types measured at 10-months of age. FINDINGS: Of the 987 children randomized to Arms C, D, and E, 936 were included in the intention-to-treat analysis. At 10-months, participants in Arm C (IPV at 14-weeks and 9-months) had ≥99% cumulative immune response to all three poliovirus types which was significantly higher than the 77-81% observed in Arm E (IPV at 6 and 14-weeks). Participants in Arm D (IPV at 6-weeks and 9-months) had cumulative immune responses of 98-99% which was significantly higher than that of Arm E (p value < 0.0001) but not different from Arm C. INTERPRETATION: Results support current SAGE recommendations for IPV following OPV cessation and provide evidence that the schedule of two full IPV doses could begin as early as 6-weeks. |
Modeling poliovirus surveillance and immunization campaign quality monitoring costs for Pakistan and Afghanistan for 2019-2023
Kalkowska DA , Pallansch MA , Cochi SL , Thompson KM . Open Forum Infect Dis 2021 8 (7) ofab264 BACKGROUND: The Global Polio Eradication Initiative (GPEI) Strategic Plan for 2019-2023 includes commitments to monitor the quality of immunization campaigns using lot quality assurance sampling surveys (LQAS) and to support poliovirus surveillance in Pakistan and Afghanistan. METHODS: We analyzed LQAS and poliovirus surveillance data between 2016 and 2020, which included both acute flaccid paralysis (AFP) case-based detection and the continued expansion of environmental surveillance (ES). Using updated estimates for unit costs, we explore the costs of different options for future poliovirus monitoring and surveillance for Pakistan and Afghanistan. RESULTS: The relative value of the information provided by campaign quality monitoring and surveillance remains uncertain and depends on the design, implementation, and performance of the systems. Prospective immunization campaign quality monitoring (through LQAS) and poliovirus surveillance will require tens of millions of dollars each year for the foreseeable future for Pakistan and Afghanistan. CONCLUSIONS: LQAS campaign monitoring as currently implemented in Pakistan and Afghanistan provides limited and potentially misleading information about immunization quality. AFP surveillance in Pakistan and Afghanistan provides the most reliable evidence of transmission, whereas ES provides valuable supplementary information about the extent of transmission in the catchment areas represented at the time of sample collection. |
Serotype 2 oral poliovirus vaccine (OPV2) choices and the consequences of delaying outbreak response.
Kalkowska DA , Pallansch MA , Wassilak SGF , Cochi SL , Thompson KM . Vaccine 2021 41 Suppl 1 A136-A141 The Global Polio Eradication Initiative (GPEI) faces substantial challenges with managing outbreaks of serotype 2 circulating vaccine-derived polioviruses (cVDPV2s) in 2021. A full five years after the globally coordinated removal of serotype 2 oral poliovirus vaccine (OPV2) from trivalent oral poliovirus vaccine (tOPV) for use in national immunization programs, cVDPV2s did not die out. Since OPV2 cessation, responses to outbreaks caused by cVDPV2s mainly used serotype 2 monovalent OPV (mOPV2) from a stockpile. A novel vaccine developed from a genetically stabilized OPV2 strain (nOPV2) promises to potentially facilitate outbreak response with lower prospective risks, although its availability and properties in the field remain uncertain. Using an established global poliovirus transmission model and building on a related analysis that characterized the impacts of disruptions in GPEI activities caused by the COVID-19 pandemic, we explore the implications of trade-offs associated with delaying outbreak response to avoid using mOPV2 by waiting for nOPV2 availability (or equivalently, delayed responses waiting for national validation of meeting the criteria for nOPV2 initial use). Consistent with prior modeling, responding as quickly as possible with available mOPV2 promises to reduce the expected burden of disease in the outbreak population and to reduce the chances for the outbreak virus to spread to other areas. Delaying cVDPV2 outbreak response (e.g., modeled as no response January-June 2021) to wait for nOPV2 can considerably increase the total expected cases (e.g., by as many as 1,300 cVDPV2 cases in the African region during 2021-2023) and increases the likelihood of triggering the need to restart widescale preventive use of an OPV2-containing vaccine in national immunization programs that use OPV. Countries should respond to any cVDPV2 outbreaks quickly with rounds that achieve high coverage using any available OPV2, and plan to use nOPV2, if needed, once it becomes widely available based on evidence that it is as effective but safer in populations than mOPV2. |
The impact of disruptions caused by the COVID-19 pandemic on global polio eradication.
Kalkowska DA , Voorman A , Pallansch MA , Wassilak SGF , Cochi SL , Badizadegan K , Thompson KM . Vaccine 2021 41 Suppl 1 A12-A18 In early 2020, the COVID-19 pandemic led to substantial disruptions in global activities. The disruptions also included intentional and unintentional reductions in health services, including immunization campaigns against the transmission of wild poliovirus (WPV) and persistent serotype 2 circulating vaccine-derived poliovirus (cVDPV2). Building on a recently updated global poliovirus transmission and Sabin-strain oral poliovirus vaccine (OPV) evolution model, we explored the implications of immunization disruption and restrictions of human interactions (i.e., population mixing) on the expected incidence of polio and on the resulting challenges faced by the Global Polio Eradication Initiative (GPEI). We demonstrate that with some resumption of activities in the fall of 2020 to respond to cVDPV2 outbreaks and full resumption on January 1, 2021 of all polio immunization activities to pre-COVID-19 levels, the GPEI could largely mitigate the impact of COVID-19 to the delays incurred. The relative importance of reduced mixing (leading to potentially decreased incidence) and reduced immunization (leading to potentially increased expected incidence) depends on the timing of the effects. Following resumption of immunization activities, the GPEI will likely face similar barriers to eradication of WPV and elimination of cVDPV2 as before COVID-19. The disruptions from the COVID-19 pandemic may further delay polio eradication due to indirect effects on vaccine and financial resources. |
Updated characterization of poliovirus transmission in Pakistan and Afghanistan and the impacts of different outbreak response vaccine options.
Kalkowska DA , Pallansch MA , Cochi SL , Thompson KM . J Infect Dis 2021 224 (9) 1529-1538 BACKGROUND: Pakistan and Afghanistan remain the only reservoirs of wild poliovirus transmission. Prior modeling suggested that before the COVID-19 pandemic, plans to stop the transmission of serotype 1 wild poliovirus (WPV1) and persistent serotype 2 circulating vaccine-derived poliovirus (cVDPV2) did not appear on track to succeed. METHODS: We updated an existing poliovirus transmission and Sabin-strain oral poliovirus vaccine (OPV) evolution model for Pakistan and Afghanistan to characterize the impacts of immunization disruptions and restrictions on human interactions (i.e., population mixing) due to the COVID-19 pandemic. We also consider different options for responding to outbreaks and for preventive supplementary immunization activities (SIAs). RESULTS: The modeling suggests that with some resumption of activities in the fall of 2020 to respond to cVDPV2 outbreaks and full resumption on January 1, 2021 of all polio immunization activities to pre-COVID-19 levels, Pakistan and Afghanistan would remain off-track for stopping all transmission through 2023 without improvements in quality. CONCLUSIONS: Using trivalent OPV (tOPV) for SIAs instead of serotype 2 monovalent OPV (mOPV2) offers substantial benefits for ending the transmission of both WPV1 and cVDPV2, because tOPV increases population immunity for both serotypes 1 and 2 while requiring fewer SIA rounds, when effectively delivered in transmission areas. |
Updated Characterization of Outbreak Response Strategies for 2019-2029: Impacts of Using a Novel Type 2 Oral Poliovirus Vaccine Strain.
Kalkowska DA , Pallansch MA , Wilkinson A , Bandyopadhyay AS , Konopka-Anstadt JL , Burns CC , Oberste MS , Wassilak SGF , Badizadegan K , Thompson KM . Risk Anal 2020 41 (2) 329-348 Delays in achieving the global eradication of wild poliovirus transmission continue to postpone subsequent cessation of all oral poliovirus vaccine (OPV) use. Countries must stop OPV use to end all cases of poliomyelitis, including vaccine-associated paralytic polio (VAPP) and cases caused by vaccine-derived polioviruses (VDPVs). The Global Polio Eradication Initiative (GPEI) coordinated global cessation of all type 2 OPV (OPV2) use in routine immunization in 2016 but did not successfully end the transmission of type 2 VDPVs (VDPV2s), and consequently continues to use type 2 OPV (OPV2) for outbreak response activities. Using an updated global poliovirus transmission and OPV evolution model, we characterize outbreak response options for 2019-2029 related to responding to VDPV2 outbreaks with a genetically stabilized novel OPV (nOPV2) strain or with the currently licensed monovalent OPV2 (mOPV2). Given uncertainties about the properties of nOPV2, we model different assumptions that appear consistent with the evidence on nOPV2 to date. Using nOPV2 to respond to detected cases may reduce the expected VDPV and VAPP cases and the risk of needing to restart OPV2 use in routine immunization compared to mOPV2 use for outbreak response. The actual properties, availability, and use of nOPV2 will determine its effects on type 2 poliovirus transmission in populations. Even with optimal nOPV2 performance, countries and the GPEI would still likely need to restart OPV2 use in routine immunization in OPV-using countries if operational improvements in outbreak response to stop the transmission of cVDPV2s are not implemented effectively. |
Progress toward poliovirus containment implementation - worldwide, 2019-2020
Moffett DB , Llewellyn A , Singh H , Saxentoff E , Partridge J , Boualam L , Pallansch M , Wassilak S , Asghar H , Roesel S , Grabovac V , Rey-Benito G , Barnor J , Theo A , Swan J , Iakovenko M , Baig N , Gurung S , Pandel E , Zaffran M . MMWR Morb Mortal Wkly Rep 2020 69 (37) 1330-1333 Since 1988, when World Health Organization (WHO) Member States and partners launched the Global Polio Eradication Initiative, the number of wild poliovirus (WPV) cases has declined from 350,000 in 125 countries to 176 in only two countries in 2019 (1). The Global Commission for the Certification of Poliomyelitis Eradication (GCC) declared two of the three WPV types, type 2 (WPV2) and type 3 (WPV3), eradicated globally in 2015 and 2019, respectively (1). Wild poliovirus type 1 (WPV1) remains endemic in Afghanistan and Pakistan (1). Containment under strict biorisk management measures is vital to prevent reintroduction of eradicated polioviruses into communities from poliovirus facilities. In 2015, Member States committed to contain type 2 polioviruses (PV2) in poliovirus-essential facilities (PEFs) certified in accordance with a global standard (2). Member states agreed to report national PV2 inventories annually, destroy unneeded PV2 materials, and, if retaining PV2 materials, establish national authorities for containment (NACs) and a PEF auditing process. Since declaration of WPV3 eradication in October 2019, these activities are also required with WPV3 materials. Despite challenges faced during 2019-2020, including the coronavirus disease 2019 (COVID-19) pandemic, the global poliovirus containment program continues to work toward important milestones. To maintain progress, all WHO Member States are urged to adhere to the agreed containment resolutions, including officially establishing legally empowered NACs and submission of PEF Certificates of Participation. |
The long and winding road to eradicate vaccine-related polioviruses
Cochi SL , Pallansch MA . J Infect Dis 2020 223 (1) 7-9 As the vaccine of choice for the Global Polio Eradication Initiative (GPEI), oral poliovirus vaccine (OPV) is inexpensive, easy to administer, and can provide good protection against poliomyelitis and poliovirus infection, through durable humoral immunity and induction of intestinal mucosal immunity. Even though trivalent OPV is a safe and effective vaccine and has a remarkable disease elimination record, all 3 strains are live attenuated RNA viruses capable of genetic mutation during replication. This means that polioviruses in OPV can undergo genetic changes in vaccine recipients to reverse attenuation. This inherent instability represents a key disadvantage of OPV that is manifest in some of the current polio eradication challenges. |
Updated Characterization of Post-OPV Cessation Risks: Lessons from 2019 Serotype 2 Outbreaks and Implications for the Probability of OPV Restart.
Kalkowska DA , Pallansch MA , Cochi SL , Kovacs SD , Wassilak SGF , Thompson KM . Risk Anal 2020 41 (2) 320-328 After the globally coordinated cessation of any serotype of oral poliovirus vaccine (OPV), some risks remain from undetected, existing homotypic OPV-related transmission and/or restarting transmission due to several possible reintroduction risks. The Global Polio Eradication Initiative (GPEI) coordinated global cessation of serotype 2-containing OPV (OPV2) in 2016. Following OPV2 cessation, the GPEI and countries implemented activities to withdraw all the remaining trivalent OPV, which contains all three poliovirus serotypes (i.e., 1, 2, and 3), from the supply chain and replace it with bivalent OPV (containing only serotypes 1 and 3). However, as of early 2020, monovalent OPV2 use for outbreak response continues in many countries. In addition, outbreaks observed in 2019 demonstrated evidence of different types of risks than previously modeled. We briefly review the 2019 epidemiological experience with serotype 2 live poliovirus outbreaks and propose a new risk for unexpected OPV introduction for inclusion in global modeling of OPV cessation. Using an updated model of global poliovirus transmission and OPV evolution with and without consideration of this new risk, we explore the implications of the current global situation with respect to the likely need to restart preventive use of OPV2 in OPV-using countries. Simulation results without this new risk suggest OPV2 restart will likely need to occur (81% of 100 iterations) to manage the polio endgame based on the GPEI performance to date with existing vaccine tools, and with the new risk of unexpected OPV introduction the expected OPV2 restart probability increases to 89%. Contingency planning requires new OPV2 bulk production, including genetically stabilized OPV2 strains. |
Clinical and virologic characteristics of the first 12 patients with coronavirus disease 2019 (COVID-19) in the United States.
Kujawski SA , Wong KK , Collins JP , Epstein L , Killerby ME , Midgley CM , Abedi GR , Ahmed NS , Almendares O , Alvarez FN , Anderson KN , Balter S , Barry V , Bartlett K , Beer K , Ben-Aderet MA , Benowitz I , Biggs HM , Binder AM , Black SR , Bonin B , Bozio CH , Brown CM , Bruce H , Bryant-Genevier J , Budd A , Buell D , Bystritsky R , Cates J , Charles EM , Chatham-Stephens K , Chea N , Chiou H , Christiansen D , Chu V , Cody S , Cohen M , Conners EE , Curns AT , Dasari V , Dawson P , DeSalvo T , Diaz G , Donahue M , Donovan S , Duca LM , Erickson K , Esona MD , Evans S , Falk J , Feldstein LR , Fenstersheib M , Fischer M , Fisher R , Foo C , Fricchione MJ , Friedman O , Fry A , Galang RR , Garcia MM , Gerber SI , Gerrard G , Ghinai I , Gounder P , Grein J , Grigg C , Gunzenhauser JD , Gutkin GI , Haddix M , Hall AJ , Han GS , Harcourt J , Harriman K , Haupt T , Haynes AK , Holshue M , Hoover C , Hunter JC , Jacobs MW , Jarashow C , Joshi K , Kamali T , Kamili S , Kim L , Kim M , King J , Kirking HL , Kita-Yarbro A , Klos R , Kobayashi M , Kocharian A , Komatsu KK , Koppaka R , Layden JE , Li Y , Lindquist S , Lindstrom S , Link-Gelles R , Lively J , Livingston M , Lo K , Lo J , Lu X , Lynch B , Madoff L , Malapati L , Marks G , Marlow M , Mathisen GE , McClung N , McGovern O , McPherson TD , Mehta M , Meier A , Mello L , Moon SS , Morgan M , Moro RN , Murray J , Murthy R , Novosad S , Oliver SE , O’Shea J , Pacilli M , Paden CR , Pallansch MA , Patel M , Patel S , Pedraza I , Pillai SK , Pindyck T , Pray I , Queen K , Quick N , Reese H , Reporter R , Rha B , Rhodes H , Robinson S , Robinson P , Rolfes MA , Routh JA , Rubin R , Rudman SL , Sakthivel SK , Scott S , Shepherd C , Shetty V , Smith EA , Smith S , Stierman B , Stoecker W , Sunenshine R , Sy-Santos R , Tamin A , Tao Y , Terashita D , Thornburg NJ , Tong S , Traub E , Tural A , Uehara A , Uyeki TM , Vahey G , Verani JR , Villarino E , Wallace M , Wang L , Watson JT , Westercamp M , Whitaker B , Wilkerson S , Woodruff RC , Wortham JM , Wu T , Xie A , Yousaf A , Zahn M , Zhang J . Nat Med 2020 26 (6) 861-868 Data on the detailed clinical progression of COVID-19 in conjunction with epidemiological and virological characteristics are limited. In this case series, we describe the first 12 US patients confirmed to have COVID-19 from 20 January to 5 February 2020, including 4 patients described previously(1-3). Respiratory, stool, serum and urine specimens were submitted for SARS-CoV-2 real-time reverse-transcription polymerase chain reaction (rRT-PCR) testing, viral culture and whole genome sequencing. Median age was 53 years (range: 21-68); 8 patients were male. Common symptoms at illness onset were cough (n = 8) and fever (n = 7). Patients had mild to moderately severe illness; seven were hospitalized and demonstrated clinical or laboratory signs of worsening during the second week of illness. No patients required mechanical ventilation and all recovered. All had SARS-CoV-2 RNA detected in respiratory specimens, typically for 2-3 weeks after illness onset. Lowest real-time PCR with reverse transcription cycle threshold values in the upper respiratory tract were often detected in the first week and SARS-CoV-2 was cultured from early respiratory specimens. These data provide insight into the natural history of SARS-CoV-2. Although infectiousness is unclear, highest viral RNA levels were identified in the first week of illness. Clinicians should anticipate that some patients may worsen in the second week of illness. |
Modeling poliovirus transmission in Borno and Yobe, Northeast Nigeria
Kalkowska DA , Franka R , Higgins J , Kovacs SD , Forbi JC , Wassilak SGF , Pallansch MA , Thompson KM . Risk Anal 2020 41 (2) 289-302 Beginning in 2013, multiple local government areas (LGAs) in Borno and Yobe in northeast Nigeria and other parts of the Lake Chad basin experienced a violent insurgency that resulted in substantial numbers of isolated and displaced people. Northeast Nigeria represents the last known reservoir country of wild poliovirus (WPV) transmission in Africa, with detection of paralytic cases caused by serotype 1 WPV in 2016 in Borno and serotype 3 WPV in late 2012. Parts of Borno and Yobe are also problematic areas for transmission of serotype 2 circulating vaccine-derived polioviruses, and they continue to face challenges associated with conflict and inadequate health services in security-compromised areas that limit both immunization and surveillance activities. We model poliovirus transmission of all three serotypes for Borno and Yobe using a deterministic differential equation-based model that includes four subpopulations to account for limitations in access to immunization services and dynamic restrictions in population mixing. We find that accessibility issues and insufficient immunization allow for prolonged poliovirus transmission and potential undetected paralytic cases, although as of the end of 2019, including responsive program activities in the modeling suggest die out of indigenous serotypes 1 and 3 WPVs prior to 2020. Specifically, recent and current efforts to access isolated populations and provide oral poliovirus vaccine continue to reduce the risks of sustained and undetected transmission, although some uncertainty remains. Continued improvement in immunization and surveillance in the isolated subpopulations should minimize these risks. Stochastic modeling can build on this analysis to characterize the implications for undetected transmission and confidence about no circulation. |
Evolving epidemiology of poliovirus serotype 2 following withdrawal of the type 2 oral poliovirus vaccine
Macklin GR , O'Reilly KM , Grassly NC , Edmunds WJ , Mach O , Santhana Gopala Krishnan R , Voorman A , Vertefeuille JF , Abdelwahab J , Gumede N , Goel A , Sosler S , Sever J , Bandyopadhyay AS , Pallansch MA , Nandy R , Mkanda P , Diop OM , Sutter RW . Science 2020 368 (6489) 401-405 While there have been no cases of type-2 wild poliovirus for over 20 years, transmission of type-2 vaccine-derived poliovirus (VDPV2) and associated paralytic cases in several continents represent a threat to eradication. The withdrawal of the type-2 component of oral poliovirus vaccine (OPV2) was implemented in April 2016 to stop VDPV2 emergence and secure eradication of all poliovirus type 2. Globally, children born after this date have limited immunity to prevent transmission. Using a statistical model, we estimate the emergence date and source of VDPV2s detected between May 2016 and November 2019. Outbreak response campaigns with monovalent OPV2 are the only available method to induce immunity to prevent transmission. Yet, our analysis shows that using monovalent OPV2 is generating more paralytic VDPV2 outbreaks with the potential for establishing endemic transmission. The novel OPV2 is urgently required, alongside a contingency strategy if this vaccine does not materialize or perform as anticipated. |
Neutralization capacity of highly divergent type 2 vaccine-derived polioviruses from immunodeficient patients
McDonald SL , Weldon WC , Wei L , Chen Q , Shaw J , Zhao K , Jorba J , Kew OM , Pallansch MA , Burns CC , Oberste MS . Vaccine 2020 38 (14) 3042-3049 The use of the oral poliovirus vaccine (OPV) in developing countries has reduced the incidence of poliomyelitis by >99% since 1988 and is the primary tool for global polio eradication. Spontaneous reversions of the vaccine virus to a neurovirulent form can impede this effort. In persons with primary B-cell immunodeficiencies, exposure to OPV can result in chronic infection, mutation, and excretion of immunodeficiency-associated vaccine-derived polioviruses, (iVDPVs). These iVDPVs may have the potential for transmission in a susceptible population and cause paralysis. The extent to which sera from OPV recipients are able to neutralize iVDPVs with varying degrees of antigenic site substitutions is investigated here. We tested sera from a population immunized with a combination vaccine schedule (both OPV and inactivated polio vaccine) against a panel of iVDPVs and found that increases in amino acid substitution in the P1 capsid protein resulted in a decrease in the neutralizing capacity of the sera. This study underscores the importance of maintaining high vaccine coverage in areas of OPV use as well as active surveillance of those known to be immunocompromised. |
First Case of 2019 Novel Coronavirus in the United States.
Holshue ML , DeBolt C , Lindquist S , Lofy KH , Wiesman J , Bruce H , Spitters C , Ericson K , Wilkerson S , Tural A , Diaz G , Cohn A , Fox L , Patel A , Gerber SI , Kim L , Tong S , Lu X , Lindstrom S , Pallansch MA , Weldon WC , Biggs HM , Uyeki TM , Pillai SK . N Engl J Med 2020 382 (10) 929-936 An outbreak of novel coronavirus (2019-nCoV) that began in Wuhan, China, has spread rapidly, with cases now confirmed in multiple countries. We report the first case of 2019-nCoV infection confirmed in the United States and describe the identification, diagnosis, clinical course, and management of the case, including the patient's initial mild symptoms at presentation with progression to pneumonia on day 9 of illness. This case highlights the importance of close coordination between clinicians and public health authorities at the local, state, and federal levels, as well as the need for rapid dissemination of clinical information related to the care of patients with this emerging infection. |
Global transmission of live polioviruses: Updated dynamic modeling of the polio endgame
Kalkowska DA , Pallansch MA , Wassilak SGF , Cochi SL , Thompson KM . Risk Anal 2020 41 (2) 248-265 Nearly 20 years after the year 2000 target for global wild poliovirus (WPV) eradication, live polioviruses continue to circulate with all three serotypes posing challenges for the polio endgame. We updated a global differential equation-based poliovirus transmission and stochastic risk model to include programmatic and epidemiological experience through January 2020. We used the model to explore the likely dynamics of poliovirus transmission for 2019-2023, which coincides with a new Global Polio Eradication Initiative Strategic Plan. The model stratifies the global population into 72 blocks, each containing 10 subpopulations of approximately 10.7 million people. Exported viruses go into subpopulations within the same block and within groups of blocks that represent large preferentially mixing geographical areas (e.g., continents). We assign representative World Bank income levels to the blocks along with polio immunization and transmission assumptions, which capture some of the heterogeneity across countries while still focusing on global poliovirus transmission dynamics. We also updated estimates of reintroduction risks using available evidence. The updated model characterizes transmission dynamics and resulting polio cases consistent with the evidence through 2019. Based on recent epidemiological experience and prospective immunization assumptions for the 2019-2023 Strategic Plan, the updated model does not show successful eradication of serotype 1 WPV by 2023 or successful cessation of oral poliovirus vaccine serotype 2-related viruses. |
Update on vaccine-derived poliovirus outbreaks - worldwide, January 2018-June 2019
Jorba J , Diop OM , Iber J , Henderson E , Zhao K , Quddus A , Sutter R , Vertefeuille JF , Wenger J , Wassilak SGF , Pallansch MA , Burns CC . MMWR Morb Mortal Wkly Rep 2019 68 (45) 1024-1028 Certification of global eradication of indigenous wild poliovirus type 2 occurred in 2015 and of type 3 in 2019. Since the launch of the Global Polio Eradication Initiative (GPEI) in 1988 and broad use of live, attenuated oral poliovirus vaccine (OPV), the number of wild poliovirus cases has declined >99.99% (1). Genetically divergent vaccine-derived poliovirus* (VDPV) strains can emerge during vaccine use and spread in underimmunized populations, becoming circulating VDPV (cVDPV) strains, and resulting in outbreaks of paralytic poliomyelitis.(dagger) In April 2016, all oral polio vaccination switched from trivalent OPV (tOPV; containing vaccine virus types 1, 2, and 3) to bivalent OPV (bOPV; containing types 1 and 3) (2). Monovalent type 2 OPV (mOPV2) is used in response campaigns to control type 2 cVDPV (cVDPV2) outbreaks. This report presents data on cVDPV outbreaks detected during January 2018-June 2019 (as of September 30, 2019). Compared with January 2017-June 2018 (3), the number of reported cVDPV outbreaks more than tripled, from nine to 29; 25 (86%) of the outbreaks were caused by cVDPV2. The increase in the number of outbreaks in 2019 resulted from VDPV2 both inside and outside of mOPV2 response areas. GPEI is planning future use of a novel type 2 OPV, stabilized to decrease the likelihood of reversion to neurovirulence. However, all countries must maintain high population immunity to decrease the risk for cVDPV emergence. Cessation of all OPV use after certification of polio eradication will eliminate the risk for VDPV emergence. |
Updated modelling of the prevalence of immunodeficiency-associated long-term vaccine-derived poliovirus (iVDPV) excreters
Kalkowska DA , Pallansch MA , Thompson KM . Epidemiol Infect 2019 147 e295 Conditions and evidence continue to evolve related to the prediction of the prevalence of immunodeficiency-associated long-term vaccine-derived poliovirus (iVDPV) excreters, which affect assumptions related to forecasting risks and evaluating potential risk management options. Multiple recent reviews provided information about individual iVDPV excreters, but inconsistencies among the reviews raise some challenges. This analysis revisits the available evidence related to iVDPV excreters and provides updated model estimates that can support future risk management decisions. The results suggest that the prevalence of iVDPV excreters remains highly uncertain and variable, but generally confirms the importance of managing the risks associated with iVDPV excreters throughout the polio endgame in the context of successful cessation of all oral poliovirus vaccine use. |
Acute flaccid myelitis in the United States: 2015-2017
Ayers T , Lopez A , Lee A , Kambhampati A , Nix WA , Henderson E , Rogers S , Weldon WC , Oberste MS , Sejvar J , Hopkins SE , Pallansch MA , Routh JA , Patel M . Pediatrics 2019 144 (5) BACKGROUND: Acute flaccid myelitis (AFM) is a neurologic condition characterized by flaccid limb weakness. After a large number of reports of AFM in 2014, the Centers for Disease Control and Prevention began standardized surveillance in the United States to characterize the disease burden and explore potential etiologies and epidemiologic associations. METHODS: Persons meeting the clinical case criteria of acute flaccid limb weakness from January 1, 2015, through December 31, 2017, were classified as confirmed (spinal cord gray matter lesions on MRI) or probable (white blood cell count >5 cells per mm(3) in cerebrospinal fluid [CSF]). We describe clinical, radiologic, laboratory, and epidemiologic findings of pediatric patients (age </=21 years) confirmed with AFM. RESULTS: Of 305 children reported from 43 states, 193 were confirmed and 25 were probable. Of confirmed patients, 61% were male, with a median age of 6 years (range: 3 months to 21 years; interquartile range: 3 to 10 years). An antecedent respiratory or febrile illness was reported in 79% with a median of 5 days (interquartile range: 2 to 7 days) before limb weakness. Among 153 sterile-site specimens (CSF and serum) submitted to the Centers for Disease Control and Prevention, coxsackievirus A16 was detected in CSF and serum of one case patient and enterovirus D68 was detected in serum of another. Of 167 nonsterile site (respiratory and stool) specimens, 28% tested positive for enterovirus or rhinovirus. CONCLUSIONS: AFM surveillance data suggest a viral etiology, including enteroviruses. Further study is ongoing to better characterize the etiology, pathogenesis, and risk factors of this rare condition. |
Immunogenicity of full and fractional dose of inactivated poliovirus vaccine for use in routine immunisation and outbreak response: an open-label, randomised controlled trial
Snider CJ , Zaman K , Estivariz CF , Yunus M , Weldon WC , Wannemuehler KA , Oberste MS , Pallansch MA , Wassilak SG , Bari TIA , Anand A . Lancet 2019 393 (10191) 2624-2634 BACKGROUND: Intradermal administration of fractional inactivated poliovirus vaccine (fIPV) is a dose-sparing alternative to the intramuscular full dose. We aimed to compare the immunogenicity of two fIPV doses versus one IPV dose for routine immunisation, and also assessed the immunogenicity of an fIPV booster dose for an outbreak response. METHODS: We did an open-label, randomised, controlled, inequality, non-inferiority trial in two clinics in Dhaka, Bangladesh. Healthy infants were randomly assigned at 6 weeks to one of four groups: group A received IPV at age 14 weeks and IPV booster at age 22 weeks; group B received IPV at age 14 weeks and fIPV booster at age 22 weeks; group C received IPV at age 6 weeks and fIPV booster at age 22 weeks; and group D received fIPV at 6 weeks and 14 weeks and fIPV booster at age 22 weeks. IPV was administered by needle-syringe as an intramuscular full dose (0.5 mL), and fIPV was administered intradermally (0.1 mL of the IPV formulation was administered using the 0.1 mL HelmJect auto-disable syringe with a Helms intradermal adapter). Both IPV and fIPV were administered on the outer, upper right thigh of infants. The primary outcome was vaccine response to poliovirus types 1, 2, and 3 at age 22 weeks (routine immunisation) and age 26 weeks (outbreak response). Vaccine response was defined as seroconversion from seronegative (<1:8) at baseline to seropositive (>/=1:8) or four-fold increase in reciprocal antibody titres adjusted for maternal antibody decay and was assessed in the modified intention-to-treat population (infants who received polio vaccines per group assignment and polio antibody titre results to serotypes 1, 2, and 3 at 6, 22, 23, and 26 weeks of age). The non-inferiority margin was 12.5%. This trial is registered with ClinicalTrials.gov, number NCT02847026. FINDINGS: Between Sept 1, 2016 and May 2, 2017, 1076 participants were randomly assigned and included in the modified intention-to-treat analysis: 271 in Group A, 267 in group B, 268 in group C, and 270 in group D. Vaccine response at 22 weeks to two doses of fIPV (group D) was significantly higher (p<0.0001) than to one dose of IPV (groups A and B) for all three poliovirus serotypes: the type 1 response comprised 212 (79% [95% CI 73-83]) versus 305 (57% [53-61]) participants, the type 2 response comprised 173 (64% [58-70]) versus 249 (46% [42-51]) participants, and the type 3 response comprised 196 (73% [67-78]) versus 196 (36% [33-41]) participants. At 26 weeks, the fIPV booster was non-inferior to IPV (group B vs group A) for serotype 1 (-1.12% [90% CI -2.18 to -0.06]), serotype 2 (0.40%, [-2.22 to 1.42]), and serotype 3 (1.51% [-3.23 to -0.21]). Of 129 adverse events, 21 were classified as serious including one death; none were attributed to IPV or fIPV. INTERPRETATION: fIPV appears to be an effective dose-sparing strategy for routine immunisation and outbreak responses. FUNDING: US Centers for Disease Control and Prevention. |
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