Last data update: May 13, 2024. (Total: 46773 publications since 2009)
Records 1-24 (of 24 Records) |
Query Trace: Kovacs S[original query] |
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Modeling the spread of circulating vaccine-derived poliovirus type 2 outbreaks and interventions: A case study of Nigeria
Sun Y , Keskinocak P , Steimle LN , Kovacs SD , Wassilak SG . Vaccine X 2024 18 100476 BACKGROUND: Despite the successes of the Global Polio Eradication Initiative, substantial challenges remain in eradicating the poliovirus. The Sabin-strain (live-attenuated) virus in oral poliovirus vaccine (OPV) can revert to circulating vaccine-derived poliovirus (cVDPV) in under-vaccinated communities, regain neurovirulence and transmissibility, and cause paralysis outbreaks. Since the cessation of type 2-containing OPV (OPV2) in 2016, there have been cVDPV type 2 (cVDPV2) outbreaks in four out of six geographical World Health Organization regions, making these outbreaks a significant public health threat. Preparing for and responding to cVDPV2 outbreaks requires an updated understanding of how different factors, such as outbreak responses with the novel type of OPV2 (nOPV2) and the existence of under-vaccinated areas, affect the disease spread. METHODS: We built a differential-equation-based model to simulate the transmission of cVDPV2 following reversion of the Sabin-strain virus in prolonged circulation. The model incorporates vaccinations by essential (routine) immunization and supplementary immunization activities (SIAs), the immunity induced by different poliovirus vaccines, and the reversion process from Sabin-strain virus to cVDPV. The model's outcomes include weekly cVDPV2 paralytic case counts and the die-out date when cVDPV2 transmission stops. In a case study of Northwest and Northeast Nigeria, we fit the model to data on the weekly cVDPV2 case counts with onset in 2018-2021. We then used the model to test the impact of different outbreak response scenarios during a prediction period of 2022-2023. The response scenarios included no response, the planned response (based on Nigeria's SIA calendar), and a set of hypothetical responses that vary in the dates at which SIAs started. The planned response scenario included two rounds of SIAs that covered almost all areas of Northwest and Northeast Nigeria except some under-vaccinated areas (e.g., Sokoto). The hypothetical response scenarios involved two, three, and four rounds of SIAs that covered the whole Northwest and Northeast Nigeria. All SIAs in tested outbreak response scenarios used nOPV2. We compared the outcomes of tested outbreak response scenarios in the prediction period. RESULTS: Modeled cVDPV2 weekly case counts aligned spatiotemporally with the data. The prediction results indicated that implementing the planned response reduced total case counts by 79% compared to no response, but did not stop the transmission, especially in under-vaccinated areas. Implementing the hypothetical response scenarios involving two rounds of nOPV2 SIAs that covered all areas further reduced cVDPV2 case counts in under-vaccinated areas by 91-95% compared to the planned response, with greater impact from completing the two rounds at an earlier time, but it did not stop the transmission. When the first two rounds were completed in early April 2022, implementing two additional rounds stopped the transmission in late January 2023. When the first two rounds were completed six weeks earlier (i.e., in late February 2022), implementing one (two) additional round stopped the transmission in early February 2023 (late November 2022). The die out was always achieved last in the under-vaccinated areas of Northwest and Northeast Nigeria. CONCLUSIONS: A differential-equation-based model of poliovirus transmission was developed and validated in a case study of Northwest and Northeast Nigeria. The results highlighted (i) the effectiveness of nOPV2 in reducing outbreak case counts; (ii) the need for more rounds of outbreak response SIAs that covered all of Northwest and Northeast Nigeria in 2022 to stop the cVDPV2 outbreaks; (iii) that persistent transmission in under-vaccinated areas delayed the progress towards stopping outbreaks; and (iv) that a quicker outbreak response would avert more paralytic cases and require fewer SIA rounds to stop the outbreaks. |
Surveillance to track progress toward polio eradication - Worldwide, 2022-2023
Kishore N , Krow-Lucal E , Diop OM , Jorba J , Avagnan T , Grabovac V , Kfutwah AKW , Johnson T , Joshi S , Sangal L , Sharif S , Wahdan A , Tallis GF , Kovacs SD . MMWR Morb Mortal Wkly Rep 2024 73 (13) 278-285 The reliable and timely detection of poliovirus cases through surveillance for acute flaccid paralysis (AFP), supplemented by environmental surveillance of sewage samples, is a critical component of the polio eradication program. Since 1988, the number of polio cases caused by wild poliovirus (WPV) has declined by >99.9%, and eradication of WPV serotypes 2 and 3 has been certified; only serotype 1 (WPV1) continues to circulate, and transmission remains endemic in Afghanistan and Pakistan. This surveillance update evaluated indicators from AFP surveillance, environmental surveillance for polioviruses, and Global Polio Laboratory Network performance data provided by 28 priority countries for the program during 2022-2023. No WPV1 cases have been detected outside of Afghanistan and Pakistan since August 2022, when an importation into Malawi and Mozambique resulted in an outbreak during 2021-2022. During 2022-2023, among 28 priority countries, 20 (71.4%) met national AFP surveillance indicator targets, and the number of environmental surveillance sites increased. However, low national rates of reported AFP cases in priority countries in 2023 might have resulted from surveillance reporting lags; substantial national and subnational AFP surveillance gaps persist. Maintaining high-quality surveillance is critical to achieving the goal of global polio eradication. Monitoring surveillance indicators is important to identifying gaps and guiding surveillance-strengthening activities, particularly in countries at high risk for poliovirus circulation. |
Epidemiology of human seasonal coronaviruses among people with mild and severe acute respiratory illness in Blantyre, Malawi, 2011-2017
Kovacs D , Mambule I , Read JM , Kiran A , Chilombe M , Bvumbwe T , Aston S , Menyere M , Masina M , Kamzati M , Ganiza TN , Iuliano D , McMorrow M , Bar-Zeev N , Everett D , French N , Ho A . J Infect Dis 2024 BACKGROUND: The aim of this study was to characterize the epidemiology of human seasonal coronaviruses (HCoVs) in southern Malawi. METHODS: We tested for HCoVs 229E, OC43, NL63, and HKU1 using real-time polymerase chain reaction (PCR) on upper respiratory specimens from asymptomatic controls and individuals of all ages recruited through severe acute respiratory illness (SARI) surveillance at Queen Elizabeth Central Hospital, Blantyre, and a prospective influenza-like illness (ILI) observational study between 2011 and 2017. We modeled the probability of having a positive PCR for each HCoV using negative binomial models, and calculated pathogen-attributable fractions (PAFs). RESULTS: Overall, 8.8% (539/6107) of specimens were positive for ≥1 HCoV. OC43 was the most frequently detected HCoV (3.1% [191/6107]). NL63 was more frequently detected in ILI patients (adjusted incidence rate ratio [aIRR], 9.60 [95% confidence interval {CI}, 3.25-28.30]), while 229E (aIRR, 8.99 [95% CI, 1.81-44.70]) was more frequent in SARI patients than asymptomatic controls. In adults, 229E and OC43 were associated with SARI (PAF, 86.5% and 89.4%, respectively), while NL63 was associated with ILI (PAF, 85.1%). The prevalence of HCoVs was similar between children with SARI and controls. All HCoVs had bimodal peaks but distinct seasonality. CONCLUSIONS: OC43 was the most prevalent HCoV in acute respiratory illness of all ages. Individual HCoVs had distinct seasonality that differed from temperate settings. |
Historical reconstruction of inaccessibility status in Local Government Areas (LGAs) of Borno and Yobe States, Nigeria, 2010-2020
Forbi JC , Musa MS , Salawu M , Idris JM , Ba'aba AI , Higgins J , Musa AI , Bashir B , Shettima A , Njeakor N , Uzoma I , Mshelia H , Nganda GW , Mohammed KI , Bomoi IM , Chiroma U , Kovacs SD , Biya O , Waziri NE , Aina M , Adamu US , Shuaib F , Bolu O , Franka R , Wiesen E . Pan Afr Med J 2023 45 7 INTRODUCTION: ultimately detected in 2016, wild poliovirus (WPV) transmission continued undetected after 2011 in Northeast Nigeria Borno and Yobe States in security-compromised areas, inaccessible due to armed insurgency. Varying inaccessibility prevented children aged <5 years in these areas from polio vaccination interventions and surveillance, while massive population displacements occurred. We examined progress in access over time to provide data supporting a very low probability of undetected WPV circulation within remaining trapped populations after 2016. METHODS: to assess the extent of inaccessibility in security-compromised areas, we obtained empirical historical data in 2020 on a quarterly and annual basis from relevant polio eradication staff for the period 2010-2020. The extent of access to areas for immunization by recall was compared to geospatial data from vaccinator tracking. Population estimates over time in security-compromised areas were extracted from satellite imagery. We compared the historical access data from staff with tracking and population esimates. RESULTS: access varied during 2010-2020, with inaccessibility peaking during 2014-2016. We observed concurrent patterns between historical recalled data on inaccessibility and contemporaneous satellite imagery on population displacements, which increased confidence in the quality of recalled data. CONCLUSION: staff-recalled access was consistent with vaccinator tracking and satellite imagery of population displacments. Despite variability in inaccessibility over time, innovative immunization initiatives were implemented as access allowed and surveillance initiatives were initiated to search for poliovirus transmission. Along with escape and liberation of residents by the military in some geographic areas, these initiatives resulted in a massive reduction in the size of the unvaccinated population remaining resident. |
Bivalent mRNA vaccine improves antibody-mediated neutralization of many SARS-CoV-2 Omicron lineage variants (preprint)
Jiang N , Wang L , Hatta M , Feng C , Currier M , Lin X , Hossain J , Cui D , Mann BR , Kovacs NA , Wang W , Atteberry G , Wilson M , Chau R , Lacek KA , Paden CR , Hassell N , Rambo-Martin B , Barnes JR , Kondor RJ , Self WH , Rhoads JP , Baughman A , Chappell JD , Shapiro NI , Gibbs KW , Hager DN , Lauring AS , Surie D , McMorrow ML , Thornburg NJ , Wentworth DE , Zhou B . bioRxiv 2023 09 The early Omicron lineage variants evolved and gave rise to diverging lineages that fueled the COVID-19 pandemic in 2022. Bivalent mRNA vaccines, designed to broaden protection against circulating and future variants, were authorized by the U.S. Food and Drug Administration (FDA) in August 2022 and recommended by the U.S. Centers for Disease Control and Prevention (CDC) in September 2022. The impact of bivalent vaccination on eliciting neutralizing antibodies against homologous BA.4/BA.5 viruses as well as emerging heterologous viruses needs to be analyzed. In this study, we analyze the neutralizing activity of sera collected after a third dose of vaccination (2-6 weeks post monovalent booster) or a fourth dose of vaccination (2-7 weeks post bivalent booster) against 10 predominant/recent Omicron lineage viruses including BA.1, BA.2, BA.5, BA.2.75, BA.2.75.2, BN.1, BQ.1, BQ.1.1, XBB, and XBB.1. The bivalent booster vaccination enhanced neutralizing antibody titers against all Omicron lineage viruses tested, including a 10-fold increase in neutralization of BQ.1 and BQ.1.1 viruses that predominated in the U.S. during the last two months of 2022. Overall, the data indicate the bivalent vaccine booster strengthens protection against Omicron lineage variants that evolved from BA.5 and BA.2 progenitors. Copyright The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available for use under a CC0 license. |
Differential neutralization and inhibition of SARS-CoV-2 variants by antibodies elicited by COVID-19 mRNA vaccines (preprint)
Wang L , Kainulainen MH , Jiang N , Di H , Bonenfant G , Mills L , Currier M , Shrivastava-Ranjan P , Calderon BM , Sheth M , Hossain J , Lin X , Lester S , Pusch E , Jones J , Cui D , Chatterjee P , Jenks HM , Morantz E , Larson G , Hatta M , Harcourt J , Tamin A , Li Y , Tao Y , Zhao K , Burroughs A , Wong T , Tong S , Barnes JR , Tenforde MW , Self WH , Shapiro NI , Exline MC , Files DC , Gibbs KW , Hager DN , Patel M , Laufer Halpin AS , Lee JS , Xie X , Shi PY , Davis CT , Spiropoulou CF , Thornburg NJ , Oberste MS , Dugan V , Wentworth DE , Zhou B , Batra D , Beck A , Caravas J , Cintron-Moret R , Cook PW , Gerhart J , Gulvik C , Hassell N , Howard D , Knipe K , Kondor RJ , Kovacs N , Lacek K , Mann BR , McMullan LK , Moser K , Paden CR , Martin BR , Schmerer M , Shepard S , Stanton R , Stark T , Sula E , Tymeckia K , Unoarumhi Y . bioRxiv 2021 30 The evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in the emergence of many new variant lineages that have exacerbated the COVID-19 pandemic. Some of those variants were designated as variants of concern/interest (VOC/VOI) by national or international authorities based on many factors including their potential impact on vaccines. To ascertain and rank the risk of VOCs and VOIs, we analyzed their ability to escape from vaccine-induced antibodies. The variants showed differential reductions in neutralization and replication titers by post-vaccination sera. Although the Omicron variant showed the most escape from neutralization, sera collected after a third dose of vaccine (booster sera) retained moderate neutralizing activity against that variant. Therefore, vaccination remains the most effective strategy to combat the COVID-19 pandemic. |
Genomic surveillance for SARS-CoV-2 variants: Circulation of Omicron lineages - United States, January 2022-May 2023
Ma KC , Shirk P , Lambrou AS , Hassell N , Zheng XY , Payne AB , Ali AR , Batra D , Caravas J , Chau R , Cook PW , Howard D , Kovacs NA , Lacek KA , Lee JS , MacCannell DR , Malapati L , Mathew S , Mittal N , Nagilla RR , Parikh R , Paul P , Rambo-Martin BL , Shepard SS , Sheth M , Wentworth DE , Winn A , Hall AJ , Silk BJ , Thornburg N , Kondor R , Scobie HM , Paden CR . MMWR Morb Mortal Wkly Rep 2023 72 (24) 651-656 CDC has used national genomic surveillance since December 2020 to monitor SARS-CoV-2 variants that have emerged throughout the COVID-19 pandemic, including the Omicron variant. This report summarizes U.S. trends in variant proportions from national genomic surveillance during January 2022-May 2023. During this period, the Omicron variant remained predominant, with various descendant lineages reaching national predominance (>50% prevalence). During the first half of 2022, BA.1.1 reached predominance by the week ending January 8, 2022, followed by BA.2 (March 26), BA.2.12.1 (May 14), and BA.5 (July 2); the predominance of each variant coincided with surges in COVID-19 cases. The latter half of 2022 was characterized by the circulation of sublineages of BA.2, BA.4, and BA.5 (e.g., BQ.1 and BQ.1.1), some of which independently acquired similar spike protein substitutions associated with immune evasion. By the end of January 2023, XBB.1.5 became predominant. As of May 13, 2023, the most common circulating lineages were XBB.1.5 (61.5%), XBB.1.9.1 (10.0%), and XBB.1.16 (9.4%); XBB.1.16 and XBB.1.16.1 (2.4%), containing the K478R substitution, and XBB.2.3 (3.2%), containing the P521S substitution, had the fastest doubling times at that point. Analytic methods for estimating variant proportions have been updated as the availability of sequencing specimens has declined. The continued evolution of Omicron lineages highlights the importance of genomic surveillance to monitor emerging variants and help guide vaccine development and use of therapeutics. |
Surveillance to track progress toward poliomyelitis eradication - Worldwide, 2021-2022
Stehling-Ariza T , Wilkinson AL , Diop OM , Jorba J , Asghar H , Avagnan T , Grabovac V , Johnson T , Joshi S , Kfutwah AKW , Sangal L , Sharif S , Wahdan A , Tallis GF , Kovacs SD . MMWR Morb Mortal Wkly Rep 2023 72 (23) 613-620 Since the Global Polio Eradication Initiative (GPEI) was established in 1988, the number of wild poliovirus (WPV) cases has declined by >99.9%, and WPV serotypes 2 and 3 have been declared eradicated (1). By the end of 2022, WPV type 1 (WPV1) transmission remained endemic only in Afghanistan and Pakistan (2,3). However, during 2021-2022, Malawi and Mozambique reported nine WPV1 cases that were genetically linked to Pakistan (4,5), and circulating vaccine-derived poliovirus (cVDPV) outbreaks were detected in 42 countries (6). cVDPVs are oral poliovirus vaccine-derived viruses that can emerge after prolonged circulation in populations with low immunity allowing reversion to neurovirulence and can cause paralysis. Polioviruses are detected primarily through surveillance for acute flaccid paralysis (AFP), and poliovirus is confirmed through stool specimen testing. Environmental surveillance, the systematic sampling of sewage and testing for the presence of poliovirus, supplements AFP surveillance. Both surveillance systems were affected by the COVID-19 pandemic's effects on public health activities during 2020 (7,8) but improved in 2021 (9). This report updates previous reports (7,9) to describe surveillance performance during 2021-2022 in 34 priority countries.* In 2022, a total of 26 (76.5%) priority countries met the two key AFP surveillance performance indicator targets nationally compared with 24 (70.6%) countries in 2021; however, substantial gaps remain in subnational areas. Environmental surveillance expanded to 725 sites in priority countries, a 31.1% increase from the 553 sites reported in 2021. High-quality surveillance is critical to rapidly detect poliovirus transmission and enable prompt poliovirus outbreak response to stop circulation. Frequent monitoring of surveillance guides improvements to achieve progress toward polio eradication. |
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. |
Erratum: Vol. 71, No. 6.
Lambrou AS , Shirk P , Steele MK , Paul P , Paden CR , Cadwell B , Reese HE , Aoki Y , Hassell N , Caravas J , Kovacs NA , Gerhart JG , Ng HJ , Zheng XY , Beck A , Chau R , Cintron R , Cook PW , Gulvik CA , Howard D , Jang Y , Knipe K , Lacek KA , Moser KA , Paskey AC , Rambo-Martin BL , Nagilla RR , Rethchless AC , Schmerer MW , Seby S , Shephard SS , Stanton RA , Stark TJ , Uehara A , Unoarumhi Y , Bentz ML , Burhgin A , Burroughs M , Davis ML , Keller MW , Keong LM , Le SS , Lee JS , Madden Jr JC , Nobles S , Owouor DC , Padilla J , Sheth M , Wilson MM , Talarico S , Chen JC , Oberste MS , Batra D , McMullan LK , Halpin AL , Galloway SE , MacCannell DR , Kondor R , Barnes J , MacNeil A , Silk BJ , Dugan VG , Scobie HM , Wentworth DE . MMWR Morb Mortal Wkly Rep 2022 71 (14) 528 The report “Genomic Surveillance for SARS-CoV-2 Variants: Predominance of the Delta (B.1.617.2) and Omicron (B.1.1.529) Variants — United States, June 2021–January 2022” contained several errors. |
Review of use of inactivated poliovirus vaccine in campaigns to control type 2 circulating vaccine derived poliovirus (cVDPV) outbreaks
Estivariz CF , Kovacs SD , Mach O . Vaccine 2022 41 Suppl 1 A113-A121 Delivering inactivated poliovirus vaccine (IPV) with oral poliovirus vaccine (OPV) in campaigns has been explored to accelerate the control of type 2 circulating vaccine-derived poliovirus (cVDPV) outbreaks. A review of scientific literature suggests that among populations with high prevalence of OPV failure, a booster with IPV after at least two doses of OPV may close remaining humoral and mucosal immunity gaps more effectively than an additional dose of trivalent OPV. However, IPV alone demonstrates minimal advantage on humoral immunity compared with monovalent and bivalent OPV, and cannot provide the intestinal immunity that prevents infection and spread to those individuals not previously exposed to live poliovirus of the same serotype (i.e. type 2 for children born after the switch from trivalent to bivalent OPV in April 2016). A review of operational data from polio campaigns shows that addition of IPV increases the cost and logistic complexity of campaigns. As a result, campaigns in response to an outbreak often target small areas. Large campaigns require a delay to ensure logistics are in place for IPV delivery, and may need implementation in phases that last several weeks. Challenges to delivery of injectable vaccines through house-to-house visits also increases the risk of missing the children who are more likely to benefit from IPV: those with difficult access to routine immunization and other health services. Based upon this information, the Strategic Advisory Group of Experts in immunization (SAGE) recommended in October 2020 the following strategies: provision of a second dose of IPV in routine immunization to reduce the risk and number of paralytic cases in countries at risk of importation or new emergences; and use of type 2 OPV in high-quality campaigns to interrupt transmission and avoid seeding new type 2 cVDPV outbreaks. |
Analysis of population immunity to poliovirus following cessation of trivalent oral polio vaccine
Voorman A , Lyons H , Bennette C , Kovacs S , Makam JK , Vertefeuille JF , Tallis G . Vaccine 2022 41 Suppl 1 A85-A92 BACKGROUND: The global withdrawal of trivalent oral poliovirus vaccine (OPV) (tOPV, containing Sabin poliovirus strains serotypes 1, 2 and 3) from routine immunization, and the introduction of bivalent OPV (bOPV, containing Sabin poliovirus strains serotypes 1 and 3) and trivalent inactivated poliovirus vaccine (IPV) into routine immunization was expected to improve population serologic and mucosal immunity to types 1 and 3 poliovirus, while population mucosal immunity to type 2 poliovirus would decline. However, over the period since tOPV withdrawal, the implementation of preventive bOPV supplementary immunization activities (SIAs) has decreased, while outbreaks of type 2 circulating vaccine derived poliovirus (cVDPV2) have required targeted use of monovalent type 2 OPV (mOPV2). METHODS: We develop a dynamic model of OPV-induced immunity to estimate serotype-specific, district-level immunity for countries in priority regions and characterize changes in immunity since 2016. We account for the changes in routine immunization schedules and varying implementation of preventive and outbreak response SIAs, assuming homogenous coverages of 50% and 80% for SIAs. RESULTS: In areas with strong routine immunization, the switch from tOPV to bOPV has likely resulted in gains in population immunity to types 1 and 3 poliovirus. However, we estimate that improved immunogenicity of new schedules has not compensated for declines in preventive SIAs in areas with weak routine immunization. For type 2 poliovirus, without tOPV in routine immunization or SIAs, mucosal immunity has declined nearly everywhere, while use of mOPV2 has created highly heterogeneous population immunity for which it is important to take into account when responding to cVDPV2 outbreaks. CONCLUSIONS: The withdrawal of tOPV and declining allocations of resources for preventive bOPV SIAs have resulted in reduced immunity in vulnerable areas to types 1 and 3 poliovirus and generally reduced immunity to type 2 poliovirus in the regions studied, assuming homogeneous coverages of 50% and 80% for SIAs. The very low mucosal immunity to type 2 poliovirus generates substantially greater risk for further spread of cVDPV2 outbreaks. Emerging gaps in immunity to all serotypes will require judicious targeting of limited resources to the most vulnerable populations by the Global Polio Eradication Initiative (GPEI). |
Genomic Surveillance for SARS-CoV-2 Variants: Predominance of the Delta (B.1.617.2) and Omicron (B.1.1.529) Variants - United States, June 2021-January 2022.
Lambrou AS , Shirk P , Steele MK , Paul P , Paden CR , Cadwell B , Reese HE , Aoki Y , Hassell N , Caravas J , Kovacs NA , Gerhart JG , Ng HJ , Zheng XY , Beck A , Chau R , Cintron R , Cook PW , Gulvik CA , Howard D , Jang Y , Knipe K , Lacek KA , Moser KA , Paskey AC , Rambo-Martin BL , Nagilla RR , Rethchless AC , Schmerer MW , Seby S , Shephard SS , Stanton RA , Stark TJ , Uehara A , Unoarumhi Y , Bentz ML , Burhgin A , Burroughs M , Davis ML , Keller MW , Keong LM , Le SS , Lee JS , Madden Jr JC , Nobles S , Owouor DC , Padilla J , Sheth M , Wilson MM , Talarico S , Chen JC , Oberste MS , Batra D , McMullan LK , Halpin AL , Galloway SE , MacCannell DR , Kondor R , Barnes J , MacNeil A , Silk BJ , Dugan VG , Scobie HM , Wentworth DE . MMWR Morb Mortal Wkly Rep 2022 71 (6) 206-211 Genomic surveillance is a critical tool for tracking emerging variants of SARS-CoV-2 (the virus that causes COVID-19), which can exhibit characteristics that potentially affect public health and clinical interventions, including increased transmissibility, illness severity, and capacity for immune escape. During June 2021-January 2022, CDC expanded genomic surveillance data sources to incorporate sequence data from public repositories to produce weighted estimates of variant proportions at the jurisdiction level and refined analytic methods to enhance the timeliness and accuracy of national and regional variant proportion estimates. These changes also allowed for more comprehensive variant proportion estimation at the jurisdictional level (i.e., U.S. state, district, territory, and freely associated state). The data in this report are a summary of findings of recent proportions of circulating variants that are updated weekly on CDC's COVID Data Tracker website to enable timely public health action.(†) The SARS-CoV-2 Delta (B.1.617.2 and AY sublineages) variant rose from 1% to >50% of viral lineages circulating nationally during 8 weeks, from May 1-June 26, 2021. Delta-associated infections remained predominant until being rapidly overtaken by infections associated with the Omicron (B.1.1.529 and BA sublineages) variant in December 2021, when Omicron increased from 1% to >50% of circulating viral lineages during a 2-week period. As of the week ending January 22, 2022, Omicron was estimated to account for 99.2% (95% CI = 99.0%-99.5%) of SARS-CoV-2 infections nationwide, and Delta for 0.7% (95% CI = 0.5%-1.0%). The dynamic landscape of SARS-CoV-2 variants in 2021, including Delta- and Omicron-driven resurgences of SARS-CoV-2 transmission across the United States, underscores the importance of robust genomic surveillance efforts to inform public health planning and practice. |
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. |
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. |
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. |
The safety of atovaquone-proguanil for the prevention and treatment of malaria in pregnancy: A systematic review
Andrejko KL , Mayer RC , Kovacs S , Slutsker E , Bartlett E , Tan KR , Gutman JR . Travel Med Infect Dis 2019 27 20-26 BACKGROUND: Malaria infection poses a significant risk in pregnancy, yet chemoprophylaxis for pregnant women is limited. A systematic review was conducted to evaluate the incidence of adverse outcomes after atovaquone-proguanil (AP) exposure during pregnancy. METHODS: Following PRISMA guidelines, the authors searched PubMed, MEDLINE, and the Malaria in Pregnancy Consortium Library to identify relevant literature including infant outcomes after exposure to atovaquone, proguanil, or AP in pregnancy. Two authors independently screened the titles, abstracts, and full texts, and extracted data into an EpiInfo database. Overall proportions and 95% confidence intervals of adverse outcomes were determined by pooling data across studies. RESULTS: Of 455 records identified, 16 studies were included: ten AP studies and six proguanil studies. The overall proportions and 95% confidence intervals (CI) of adverse outcomes reported for the 446 women exposed to AP include miscarriage (8.08% CI: 5.07, 12.08%), stillbirth (1.05% CI: 0.03, 5.73%), early neonatal death (0% CI: 0, 7.4%), and congenital anomalies (2.56% CI: 1.28, 4.53%). CONCLUSIONS: The limited available data suggest that outcomes following AP exposure during pregnancy are similar to expected rates in similar populations. AP may be a promising option for pregnant women, but further data are needed on its safety in pregnancy. |
Safety, tolerability, and efficacy of repeated doses of dihydroartemisinin-piperaquine for prevention and treatment of malaria: a systematic review and meta-analysis
Gutman J , Kovacs S , Dorsey G , Stergachis A , Ter Kuile FO . Lancet Infect Dis 2016 17 (2) 184-193 BACKGROUND: Intermittent preventive treatment (IPT) for malaria is used in infants, children, adults, and pregnant women. Dihydroartemisinin-piperaquine (DP) is an effective, well tolerated artemisinin-based combination therapy. The long half-life of piperaquine makes it attractive for IPT. We conducted a systematic review and meta-analysis to establish the efficacy and safety of repeated treatment with DP. METHODS: Following PRISMA guidelines, we searched multiple databases on Sept 1, 2016, with the terms: "human" AND "dihydroartemisinin-piperaquine" OR "DHA-PPQ". Studies were eligible if they were randomised controlled trials (RCTs) or prospective cohort studies involving repeat exposures to standard 3-day courses of DP for either seasonal malaria chemoprevention, mass drug administration, or treatment of clinical malaria, conducted at any time and in any geographic location. Random-effects meta-analysis was used to generate pooled incidence rate ratios and relative risks, or risk differences. FINDINGS: 11 studies were included: two repeat treatment studies (one in children younger than 5 years and one in pregnant women), and nine IPT trials (five in children younger than 5 years, one in schoolchildren, one in adults, two in pregnant women). Comparator interventions included placebo, artemether-lumefantrine, sulfadoxine-pyrimethamine (SP), SP+amodiaquine, SP+piperaquine, SP+chloroquine, and co-trimoxazole. Of 14 628 participants, 3935 received multiple DP courses (2-18). Monthly IPT-DP was associated with an 84% reduction in the incidence of malaria parasitaemia measured by microscopy compared with placebo. Monthly IPT-DP was associated with fewer serious adverse events than placebo, daily co-trimoxazole, or monthly SP. Among 56 IPT-DP recipients (26 children, 30 pregnant women) with cardiac parameters, all QTc intervals were within normal limits, with no significant increase in QTc prolongation with increasing courses of DP. INTERPRETATION: Monthly DP appears well tolerated and effective for IPT. Additional data are needed in pregnancy and to further explore the cardiac safety with monthly dosing. FUNDING: Bill & Melinda Gates Foundation and NIH. |
Deconstructing the differences: a comparison of GBD 2010 and CHERG inverted question marks approach to estimating the mortality burden of diarrhea, pneumonia, and their etiologies
Kovacs SD , Mullholland K , Bosch J , Campbell H , Forouzanfar MH , Khalil I , Lim S , Liu L , Maley SN , Mathers CD , Matheson A , Mokdad AH , OBrien K , Parashar U , Schaafsma TT , Steele D , Hawes SE , Grove JT . BMC Infect Dis 2015 15 (1) 16 BACKGROUND: Pneumonia and diarrhea are leading causes of death for children under five (U5). It is challenging to estimate the total number of deaths and cause-specific mortality fractions. Two major efforts, one led by the Institute for Health Metrics and Evaluation (IHME) and the other led by the World Health Organization (WHO)/Child Health Epidemiology Reference Group (CHERG) created estimates for the burden of disease due to these two syndromes, yet their estimates differed greatly for 2010. METHODS: This paper discusses three main drivers of the differences: data sources, data processing, and covariates used for modelling. The paper discusses differences in the model assumptions for etiology-specific estimates and presents recommendations for improving future models. RESULTS: IHME inverted question marks Global Burden of Disease (GBD) 2010 study estimated 6.8 million U5 deaths compared to 7.6 million U5 deaths from CHERG. The proportional differences between the pneumonia and diarrhea burden estimates from the two groups are much larger; GBD 2010 estimated 0.847 million and CHERG estimated 1.396 million due to pneumonia. Compared to CHERG, GBD 2010 used broader inclusion criteria for verbal autopsy and vital registration data. GBD 2010 and CHERG used different data processing procedures and therefore attributed the causes of neonatal death differently. The major difference in pneumonia etiologies modeling approach was the inclusion of observational study data; GBD 2010 included observational studies. CHERG relied on vaccine efficacy studies. DISCUSSION: Greater transparency in modeling methods and more timely access to data sources are needed. In October 2013, the Bill & Melinda Gates Foundation (BMGF) hosted an expert meeting to examine possible approaches for better estimation. The group recommended examining the impact of data by systematically excluding sources in their models. GBD 2.0 will use a counterfactual approach for estimating mortality from pathogens due to specific etiologies to overcome bias of the methods used in GBD 2010 going forward. |
Comprehensive laboratory evaluation of a highly specific lateral flow assay for the presumptive identification of ricin in suspicious white powders and environmental samples
Hodge DR , Prentice KW , Ramage JG , Prezioso S , Gauthier C , Swanson T , Hastings R , Basavanna U , Datta S , Sharma SK , Garber EA , Staab A , Pettit D , Drumgoole R , Swaney E , Estacio PL , Elder IA , Kovacs G , Morse BS , Kellogg RB , Stanker L , Morse SA , Pillai SP . Biosecur Bioterror 2013 11 (4) 237-50 Ricin, a heterodimeric toxin that is present in the seeds of the Ricinus communis plant, is the biothreat agent most frequently encountered by law enforcement agencies in the United States. Even in untrained hands, the easily obtainable seeds can yield a highly toxic product that has been used in various types of threats, including "white-powder" letters. Although the vast majority of these threats are hoaxes, an impediment to accurate hazard assessments by first responders is the unreliability of rapid detection assays for ricin, such as lateral flow assays (LFAs). One of the complicating factors associated with LFAs is the incorporation of antibodies of poor specificity that cross-react with near-neighbors or with plant lectins that are capable of nonspecifically cross-linking the capture and detector antibodies. Because of the compelling and critical need to promote the interests of public safety and public health, the Department of Homeland Security conducted a comprehensive laboratory evaluation study of a commercial LFA for the rapid detection of ricin. This study was conducted using comprehensive inclusivity and exclusivity panels of ricin and near-neighbor plant materials, along with panels of lectins and "white-powders," to determine the specificity, sensitivity, limits of detection, dynamic range, and repeatability of the assay for the specific intended use of evaluating suspicious white powders and environmental samples in the field. |
Detection of novel porcine bocaviruses in fecal samples of asymptomatic pigs in Cameroon
Ndze VN , Cadar D , Csagola A , Kisfali P , Kovacs E , Farkas S , Ngu AF , Esona MD , Dan A , Tuboly T , Banyai K . Infect Genet Evol 2013 17 277-82 Improvements and widespread use of nucleic acid amplification and sequencing methods have led to the recognition of new virus diversity in various domestic animals, including pigs. In this study we utilized either virus species specific or broadly reactive PCR assays to describe the occurrence and genetic diversity of selected DNA viruses belonging to families Adenoviridae, Circoviridae, Anelloviridae and Parvoviridae in Cameroonian pigs. Fecal specimens were collected during spring of 2011. No adenoviruses, circoviruses and anelloviruses were detected, however, high prevalence and remarkable genetic diversity within the identified parvoviruses and, particularly, within bocaviruses was observed. PPV4 was the most prevalent virus (20%), followed by PBoV3 (18%), PBoV4 (18%), PBoV5 plus 6V/7V (16%), and PBoV1 plus PBoV2 (6%). The frequency of mixed infections with various combinations of these virus species reached 20%. Genetic analysis of the identified viruses showed that the capsid gene of PBoV1 and PBoV2 strains shared up to 91% and 94%nt sequence similarities to reference PBoV1 and PBoV2 strains, respectively. The identified PBoV3 and PBoV4 strains shared 95% and 98%nt identities with reference PBoV3 and PBoV4 strains, respectively, along the NS gene, whereas the PBoV5 strains shared 86%nt identities with Hungarian and 87%nt identities with Chinese PBoV5 strains along the capsid gene. In addition, a single PBoV5-like strain shared 71%nt sequence identity with other PBoV5 strains. This is the first study to report evidence of the circulation of bocaviruses in Africa and contributes to our understanding of the impact of globalization on the dispersal of new and emerging viruses. |
No interactions between previously associated 2-hour glucose gene variants and physical activity or BMI on 2-hour glucose levels.
Scott RA , Chu AY , Grarup N , Manning AK , Hivert MF , Shungin D , Tonjes A , Yesupriya A , Barnes D , Bouatia-Naji N , Glazer NL , Jackson AU , Kutalik Z , Lagou V , Marek D , Rasmussen-Torvik LJ , Stringham HM , Tanaka T , Aadahl M , Arking DE , Bergmann S , Boerwinkle E , Bonnycastle LL , Bornstein SR , Brunner E , Bumpstead SJ , Brage S , Carlson OD , Chen H , Chen YD , Chines PS , Collins FS , Couper DJ , Dennison EM , Dowling NF , Egan JS , Ekelund U , Erdos MR , Forouhi NG , Fox CS , Goodarzi MO , Grässler J , Gustafsson S , Hallmans G , Hansen T , Hingorani A , Holloway JW , Hu FB , Isomaa B , Jameson KA , Johansson I , Jonsson A , Jørgensen T , Kivimaki M , Kovacs P , Kumari M , Kuusisto J , Laakso M , Lecoeur C , Lévy-Marchal C , Li G , Loos RJ , Lyssenko V , Marmot M , Marques-Vidal P , Morken MA , Müller G , North KE , Pankow JS , Payne F , Prokopenko I , Psaty BM , Renström F , Rice K , Rotter JI , Rybin D , Sandholt CH , Sayer AA , Shrader P , Schwarz PE , Siscovick DS , Stancáková A , Stumvoll M , Teslovich TM , Waeber G , Williams GH , Witte DR , Wood AR , Xie W , Boehnke M , Cooper C , Ferrucci L , Froguel P , Groop L , Kao WH , Vollenweider P , Walker M , Watanabe RM , Pedersen O , Meigs JB , Ingelsson E , Barroso I , Florez JC , Franks PW , Dupuis J , Wareham NJ , Langenberg C . Diabetes 2012 61 (5) 1291-6 Gene-lifestyle interactions have been suggested to contribute to the development of type 2 diabetes. Glucose levels 2 h after a standard 75-g glucose challenge are used to diagnose diabetes and are associated with both genetic and lifestyle factors. However, whether these factors interact to determine 2-h glucose levels is unknown. We meta-analyzed single nucleotide polymorphism (SNP) x BMI and SNP x physical activity (PA) interaction regression models for five SNPs previously associated with 2-h glucose levels from up to 22 studies comprising 54,884 individuals without diabetes. PA levels were dichotomized, with individuals below the first quintile classified as inactive (20%) and the remainder as active (80%). BMI was considered a continuous trait. Inactive individuals had higher 2-h glucose levels than active individuals (beta = 0.22 mmol/L [95% CI 0.13-0.31], P = 1.63 x 10(-6)). All SNPs were associated with 2-h glucose (beta = 0.06-0.12 mmol/allele, P ≤ 1.53 x 10(-7)), but no significant interactions were found with PA (P > 0.18) or BMI (P ≥ 0.04). In this large study of gene-lifestyle interaction, we observed no interactions between genetic and lifestyle factors, both of which were associated with 2-h glucose. It is perhaps unlikely that top loci from genome-wide association studies will exhibit strong subgroup-specific effects, and may not, therefore, make the best candidates for the study of interactions. |
Patterns and predictors of HIV/STI risk among Latino migrant men in a new receiving community
Kissinger P , Kovacs S , Anderson-Smits C , Schmidt N , Salinas O , Hembling J , Beaulieu A , Longfellow L , Liddon N , Rice J , Shedlin M . AIDS Behav 2012 16 (1) 199-213 The purpose of this study was to examine patterns and predictors of HIV/STI risk over time among Latino migrant men in a new receiving community. Latino men (N=125) were interviewed quarterly for 18 months and HIV/STI tested annually. Selected individual, environmental and cultural factors by partner type and condom use were explored longitudinally and in a cross-section. Sex with female sex workers (FSWs) and multiple partners decreased, sex with main partners and abstinence increased, while the number of casual partners remained stable. Consistent condom use was highest with FSWs, lowest with main partners and midrange with casual partners with no trends over time. STI morbidity was low; no HIV was detected. Drug use and high mobility were associated with inconsistent condom use with FSW, whereas having family in the household was protective. HIV/STI prevention efforts should focus on drug using Latino migrants who are highly mobile and should foster healthy social connections. |
[Post vaccination rotavirus surveillance in Hungary, in 2007]
Laszlo B , Czellar E , Deak J , Juhasz A , Kovacs J , Konya J , Meszaros J , Meszner Z , Mihaly I , Molnar P , Nyul Z , Patri L , Puskas E , Schneider F , Siffel C , Toth A , Toth E , Szucs G , Banyai K . Orv Hetil 2009 150 (31) 1443-50 Vaccination is the main strategy to control severe dehydrating gastroenteritis caused by rotaviruses in early childhood. The availability of new generation rotavirus vaccines has led to an intensification of strain surveillance worldwide, in part, to gauge the impact of the possible vaccine-driven immune selection of wild-type rotavirus strains. In the present study, authors describe the strain prevalence data obtained in 2007, with the involvement of different regions of Hungary. Genomic RNA was extracted from rotavirus-positive stool samples collected mainly from children and then subjected to genotyping using multiplex RT-PCR assay. Type-specific primers targeted G1 to G4, G6, G8 to G10, and G12 VP7 specificities, and P[4], P[6], and P[8] to P[11] VP4 specificities were used. Out of 489 rotavirus-positive specimens, collected from 482 patients, 466 and 474 were successfully G and P typed, respectively, and both G and P type specificities could be assigned for 457 strains. Prevalence data showed the predominance of G4P[8] (31.5%) strains, followed by G1P[8] (28.3%), G2P[4] (19.3%), and G9P[8] (10.2%). Minority strains were G1P[4] (0.4%), G2P[8] (1.3%), G3P[9] (0.2%), G4P[6] (0.7%), G6P[9] (0.4%), G8P[8] (0.2%), G9P[4] (0.2%), G9P[6] (0.8%), and G12P[8] (0.4%). Mixed infections were found in 1.2% of the samples, while 4.9% remained partially or fully non-typified. Our data indicate that the antigen specificities of medically important rotavirus strains identified in this 1-year study are well represented in the vaccines available in the pharmaceutical private market in Hungary. Depending on the vaccination coverage achievable in the forthcoming years, the post-vaccination rotavirus strain surveillance may allow us to gain comprehensive information on the impact of rotavirus vaccines on the prevalence of circulating rotavirus strains. |
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