BACKGROUND: In 2019, following a large outbreak of typhoid fever, the Zimbabwe Ministry of Health and Child Care conducted a typhoid conjugate vaccine (TCV) vaccination campaign in nine high-risk suburbs of Harare. We aimed to evaluate TCV vaccination coverage, vaccine perceptions, and adverse events reported after vaccination. METHODS: We conducted a two-stage cluster survey to estimate vaccination coverage in the campaign target areas among children aged 6 months-15 years and to classify coverage as either adequate (≥75 % coverage) or inadequate (<75 % coverage) among adults aged 16-45 years in one suburb. Questionnaires assessed socio-demographic factors, TCV vaccination history, reasons for receiving or not receiving TCV, adverse events following immunization, and knowledge and attitudes regarding typhoid and TCV. RESULTS: A total of 1,917 children from 951 households and 298 adults from 135 households enrolled in the survey. Weighted TCV coverage among all children aged 6 months-15 years was 85.3 % (95 % CI: 82.1 %-88.0 %); coverage was 74.8 % (95 % CI: 69.4 %-79.5 %) among children aged 6 months-4 years and 89.3 % (95 % CI: 86.2 %-91.7 %) among children aged 5-15 years. Among adults, TCV coverage was classified as inadequate with a 95 % confidence interval of 55.0 %-73.1 %. Among vaccinated persons, the most reported reason for receiving TCV (96 % across all age groups) was protection from typhoid fever; the most common reasons for non-vaccination were not being in Harare during the vaccination campaign and not being aware of the campaign. Adverse events were infrequently reported in all age groups (10 %) and no serious events were reported. CONCLUSIONS: The 2019 TCV campaign achieved high coverage among school-aged children (5-15 years). Strategies to increase vaccination coverage should be explored for younger children as part of Zimbabwe's integration of TCV into the routine immunization program, and for adults during future post-outbreak campaigns.

BACKGROUND: Vaccine effectiveness (VE) is essential to monitor the performance of vaccines and generate strategic information to guide decision making. We pooled data from six Latin American countries to estimate the effectiveness of COVID-19 vaccines in preventing laboratory-confirmed SARS-CoV-2 hospitalisation during three different pandemic waves from February 2021 to September 2022. METHODS: We used a test-negative case-control design in hospitalised adults in Chile, Costa Rica, Ecuador, Guatemala, Paraguay, and Uruguay. We estimated adjusted VE by age group (18-64 and ≥65 years), vaccine type and product for primary series vaccination and booster vaccination and by time since last dose during the Omicron variant dominant period. We used mixed effects logistic regression models adjusting for sex, age, week of onset of symptom onset and pre-existing conditions with country fit as a random effect term. FINDINGS: We included 15,241 severe acute respiratory infection (SARI) patients in the analysis. Among adults 18-64 years, VE estimates for primary series vaccination during pre-Delta and Delta periods ranged by product from 66.5% to 95.1% and from 33.5% to 88.2% for older adults. During the Omicron period, VE estimates for primary series were lower and decreased by time since last vaccination, but VE increased to between 26.4% and 57.4% when a booster was administered. INTERPRETATION: mRNA and viral vector vaccines presented higher VE for both primary series and booster. While VE decreased over time, protection against severe COVID-19-associated hospitalisation increased when booster doses were administered. Vaccination with additional doses should be recommended, particularly for persons at increased risk of developing severe COVID-19. FUNDING: This work was supported by a grant from the U.S. Centers for Disease Control and Prevention (CDC) through cooperative agreements with the Pan American Health Organization/World Health Organization.

BACKGROUND: Estimating the burden of disease averted by vaccination can assist policymakers to implement, adjust, and communicate the value of vaccination programs. Demonstrating the use of a newly available modeling tool, we estimated the burden of influenza illnesses averted by seasonal influenza vaccination in El Salvador, Panama, and Peru during 2011-2017 among two influenza vaccine target populations: children aged 6-23 months and pregnant women. METHODS: We derived model inputs, including incidence, vaccine coverage, vaccine effectiveness, and multipliers from publicly available country-level influenza surveillance data and cohort studies. We also estimated changes in illnesses averted when countries' vaccine coverage was achieved using four different vaccine deployment strategies. RESULTS: Among children aged 6-23 months, influenza vaccination averted an estimated cumulative 2,161 hospitalizations, 81,907 medically-attended illnesses, and 126,987 overall illnesses during the study period, with a prevented fraction ranging from 0.3 % to 12.5 %. Among pregnant women, influenza vaccination averted an estimated cumulative 173 hospitalizations, 6,122 medically attended illnesses, and 16,412 overall illnesses, with a prevented fraction ranging from 0.2 % to 10.9 %. Compared to an influenza vaccine campaign with equal vaccine distribution during March-June, scenarios in which total cumulative coverage was achieved in March and April consistently resulted in the greatest increase in averted illness (23 %-3,129 % increase among young children and 22 %-3,260 % increase among pregnant women). DISCUSSION: Influenza vaccination campaigns in El Salvador, Panama, and Peru conducted between 2011 and 2018 prevented hundreds to thousands of influenza-associated hospitalizations and illnesses in young children and pregnant women. Existing vaccination programs could prevent additional illnesses, using the same number of vaccines, by achieving the highest possible coverage within the first two months of an influenza vaccine campaign.

To support efforts to vaccinate millions of Americans across the United States (US) against COVID-19, the US federal government (USG) launched the Pharmacy Partnership for Long-Term Care Program (PPP) in December 2020 and the Federal Retail Pharmacy Program (FRPP) in February 2021. These programs consisted of a collaborative partnership with the USG and 21 pharmacy organizations, including large retail chains, coordinating pharmacy services administrative organizations (PSAOs) representing independent retail and long-term care pharmacies, and pharmacy network administrators. These pharmacy organizations represented over 46,000 providers and created a robust channel for far-reaching COVID-19 vaccination across 56 state and local jurisdictions. PPP reported more than 8 million COVID-19 doses administered to residents and staff in long-term care facilities (LTCFs) as of June 2021. In addition, FRPP was responsible for administering more than 304 million doses, accounting for approximately 49% of all COVID-19 doses administered as of June 2023. This unprecedented public-private partnership allowed USG to rapidly adapt, expand, and aim to provide equitable access to vaccines for adults and eligible-aged children during the COVID-19 pandemic. As the largest federal COVID-19 vaccination program, the FRPP exemplifies how public-private partnerships can expand access to immunizations during a public health emergency. End-to-end informatics support helped pharmacies meet critical national public health goals and served as convenient access points for sustained health services. This manuscript describes lessons learned regarding informatics coordination with participating pharmacy partners to support the rapid and safe administration of COVID-19 vaccines across the US. The processes of onboarding to CDC's complex data network, establishing connections to state and local immunization information systems (IIS), and monitoring the quality of data pharmacy partners submitted to the CDC Data Clearinghouse (DCH) in alignment with the COVID-19 Vaccine Reporting Specifications (CVRS) are highlighted.

Nonpharmaceutical interventions (NPIs) for SARS-CoV-2 disrupted circulation of influenza. We used data from 13 African countries and generalized linear models to identify associations between levels of NPIs, using the Oxford Stringency Index, and seasonal influenza activity, using parameters derived from 2020-2022 seasonal influenza surveillance. We found that for each step increase in school closings, the average percentage of respiratory specimens testing positive for influenza across the influenza season dropped by 20% (95% CI: 1-38%); no other NPI was significant. These findings may inform interventions to slow influenza circulation in pandemics and possibly during seasonal epidemics.

BACKGROUND: Historically, lack of data on cost-effectiveness of influenza vaccination has been identified as a barrier to vaccine use in low- and middle-income countries. We conducted a systematic review of economic evaluations describing (1) costs of influenza illness; (2) costs of influenza vaccination programs; and (3) vaccination cost-effectiveness from low- and middle-income countries to assess if gaps persist that could hinder global implementation of influenza vaccination programs. METHODS AND FINDINGS: We performed a systematic search in Medline, Embase, Cochrane Library, CINAHL, and Scopus in January 2022 and October 2023 using a combination of the following key words: "influenza" AND "cost" OR "economic." The search included studies with publication years 2012 through 2022. Studies were eligible if they (1) presented original, peer-reviewed findings on cost of illness, cost of vaccination program, or cost-effectiveness of vaccination for seasonal influenza; and (2) included data for at least 1 low- or middle-income country. We abstracted general study characteristics and data specific to each of the 3 study types. Of 54 included studies, 26 presented data on cost-effectiveness, 24 on cost-of-illness, and 5 on program costs. Represented countries were classified as upper-middle income (UMIC; n = 12), lower-middle income (LMIC; n = 7), and low-income (LIC; n = 3). The most evaluated target groups were children (n = 26 studies), older adults (n = 17), and persons with chronic medical conditions (n = 12); fewer studies evaluated pregnant persons (n = 9), healthcare workers (n = 5), and persons in congregate living settings (n = 1). Costs-of-illness were generally higher in UMICs than in LMICs/LICs; however, the highest national economic burden, as a percent of gross domestic product and national health expenditure, was reported from an LIC. Among studies that evaluated the cost-effectiveness of influenza vaccine introduction, most (88%) interpreted at least 1 scenario per target group as either cost-effective or cost-saving, based on thresholds designated in the study. Key limitations of this work included (1) heterogeneity across included studies; (2) restrictiveness of the inclusion criteria used; and (3) potential for missed influenza burden from use of sentinel surveillance systems. CONCLUSIONS: The 54 studies identified in this review suggest an increased momentum to generate economic evidence about influenza illness and vaccination from low- and middle-income countries during 2012 to 2022. However, given that we observed substantial heterogeneity, continued evaluation of the economic burden of influenza illness and costs/cost-effectiveness of influenza vaccination, particularly in LICs and among underrepresented target groups (e.g., healthcare workers and pregnant persons), is needed. Use of standardized methodology could facilitate pooling across settings and knowledge sharing to strengthen global influenza vaccination programs.

BACKGROUND: During November 2019-October 2021, a pediatric influenza vaccination demonstration project was conducted in four sub-counties in Kenya. The demonstration piloted two different delivery strategies: year-round vaccination and a four-month vaccination campaign. Our objective was to compare the costs of both delivery strategies. METHODS: Cost data were collected using standardized questionnaires and extracted from government and project accounting records. We reported total costs and costs per vaccine dose administered by delivery strategy from the Kenyan government perspective in 2021 US$. Costs were separated into financial costs (monetary expenditures) and economic costs (financial costs plus the value of existing resources). We also separated costs by administrative level (national, regional, county, sub-county, and health facility) and program activity (advocacy and social mobilization; training; distribution, storage, and waste management; service delivery; monitoring; and supervision). RESULTS: The total estimated cost of the pediatric influenza demonstration project was US$ 225,269 (financial) and US$ 326,691 (economic) for the year-round delivery strategy (30,397 vaccine doses administered), compared with US$ 214,753 (financial) and US$ 242,385 (economic) for the campaign strategy (25,404 doses administered). Vaccine purchase represented the largest proportion of costs for both strategies. Excluding vaccine purchase, the cost per dose administered was US$ 1.58 (financial) and US$ 5.84 (economic) for the year-round strategy and US$ 2.89 (financial) and US$ 4.56 (economic) for the campaign strategy. CONCLUSIONS: The financial cost per dose was 83% higher for the campaign strategy than the year-round strategy due to larger expenditures for advocacy and social mobilization, training, and hiring of surge staff for service delivery. However, the economic cost per dose was more comparable for both strategies (year-round 22% higher than campaign), balanced by higher costs of operating equipment and monitoring activities for the year-round strategy. These delivery cost data provide real-world evidence to inform pediatric influenza vaccine introduction in Kenya.

INTRODUCTION: Advocacy for the provision of public health resources, including vaccine for the prevention of acute respiratory illnesses (ARIs) among older adults in India, needs evidence on costs and benefits. Using a cohort of community-dwelling adults aged 60 years and older in India, we estimated the cost of ARI episode and its determinants. METHODS: We enrolled 6016 participants in Ballabgarh, Chennai, Kolkata and Pune from July 2018 to March 2020. They were followed up weekly to identify ARI and classified them as acute upper respiratory illness (AURI) or pneumonia based on clinical features based on British Thoracic Society guidelines. All pneumonia and 20% of AURI cases were asked about the cost incurred on medical consultation, investigation, medications, transportation, food and lodging. The cost of services at public facilities was supplemented by WHO-Choosing Interventions that are Cost-Effective(CHOICE) estimates for 2019. Indirect costs incurred by the affected participant and their caregivers were estimated using human capital approach. We used generalised linear model with log link and gamma family to identify the average marginal effect of key determinants of the total cost of ARI. RESULTS: We included 2648 AURI and 1081 pneumonia episodes. Only 47% (range 36%-60%) of the participants with pneumonia sought care. The mean cost of AURI episode was US$13.9, while that of pneumonia episode was US$25.6, with indirect costs comprising three-fourths of the total. The cost was higher among older men by US$3.4 (95% CI: 1.4 to 5.3), those with comorbidities by US$4.3 (95% CI: 2.8 to 5.7) and those who sought care by US$17.2 (95% CI: 15.1 to 19.2) but not by influenza status. The mean per capita annual cost of respiratory illness was US$29.5. CONCLUSION: Given the high community disease and cost burden of ARI, intensifying public health interventions to prevent and mitigate ARI among this fast-growing older adult population in India is warranted.

Bhutan successfully introduced multiple vaccines since the establishment of the Vaccine Preventable Disease Program in 1979. Surveillance and subsequent introduction of influenza vaccination became a public health priority for the Ministry of Health following the influenza A(H1N1)pdm09 pandemic. Sentinel surveillance for influenza in Bhutan began in 2008, and a study of severe acute respiratory infection was conducted in 2017, which found the highest influenza burden in children aged <5 years and adults ≥50 years. Following review of surveillance and burden of disease data, the National Technical Advisory Group presented recommendations to Bhutan's Ministry of Health which approved influenza vaccine introduction for all five high-risk groups in the country. Upon the official launch of the program in June 2018, the Vaccine Preventable Disease Program began planning, budgeting, and procurement processes with technical and financial support from the Partnership for Influenza Vaccine Introduction, the United States Centers for Disease Control and Prevention, the Bhutan Health Trust Fund, and the World Health Organization. Influenza vaccination for high-risk groups was integrated into Bhutan's routine immunization services in all health care facilities beginning in November 2019 and vaccinated all populations in 2020 in response to the COVID-19 pandemic. Coverage levels between 2019 and 2022 were highest in children aged 6-24 months (62.5%-96.9%) and lowest in pregnant women (47.7%-62.5%). Bhutan maintained high coverage levels despite the COVID-19 pandemic by continued provision of influenza vaccine services at health centers during lockdowns, conducting communication and sensitization efforts, and using catch-up campaigns. Bhutan's experience with introducing and scaling up the influenza vaccine program contributed to the country's capacity to rapidly deploy its COVID-19 vaccination program in 2021.

In the dynamic landscape of respiratory virus vaccines, it is crucial to assess the value of novel mRNA and combination influenza/COVID-19 vaccines in low- and middle-income countries. Modeling studies, such as the one conducted by Waterlow et al., provide vital information about the cost-benefit potential of these products compared to currently licensed vaccines. However, this approach only accounts for directly measured medically attended influenza-associated illnesses and has two major limitations. First, this method fails to capture the full disease burden of influenza (including non-respiratory and non-medically attended influenza illnesses), which are particularly important drivers of disease burden in infants and older adults. Second, the model does not describe the ancillary benefits of influenza vaccination such as the attenuation of severe disease, prevention of severe non-respiratory outcomes (e.g., myocardial infarctions), or reduced antibiotic use. To obtain a comprehensive understanding of the benefits of influenza vaccines, we must strive to improve the inputs for future modeling-based evaluations.

Monitoring COVID-19 vaccination coverage among nursing home (NH) residents and staff is important to ensure high coverage and guide patient-safety policies. With the termination of the federal Pharmacy Partnership for Long-Term Care Program, another source of facility-based vaccination data is needed. We compared numbers of COVID-19 vaccinations administered to NH residents and staff reported by pharmacies participating in the temporary federal Pharmacy Partnership for Long-Term Care Program with those reported by NHs participating in new COVID-19 vaccination modules of CDC’s National Healthcare Safety Network (NHSN). Pearson correlation coefficients comparing the number vaccinated between the two approaches were 0.89, 0.96, and 0.97 for residents and 0.74, 0.90, and 0.90 for staff, in the weeks ending January 3, 10, and 17, respectively. Based on subsequent NHSN reporting, vaccination coverage with ≥1 vaccine dose reached 77% for residents and 50% for staff the week ending January 31 and plateaued through April 2021.Three-question summary boxWhat is the current understanding of the subject?Because of high risk of disease, nursing home residents and staff were prioritized for COVID-19 vaccination when doses were limited.What does this report add to the literature?National monitoring of nursing home residents and staff vaccination coverage through the CDC National Healthcare Safety Network (NHSN) correlated with vaccination administration reports from the federal Pharmacy Partnership for Long-Term Care Program in January 2021. NHSN-reported vaccination coverage rates plateaued from February through April 2021.What are the implications for public health practice?NHSN can track COVID-19 vaccination in nursing homes and help guide efforts to increase vaccine uptake in residents and staff.Competing Interest StatementThe authors have declared no competing interest.Funding StatementThe authors received no financial support for the research, authorship, and/or publication of this article.Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:This activity was reviewed by CDC and was conducted consistent with applicable federal law and CDC policy (See e.g., 45 C.F.R. part 46, 21 C.F.R. part 56; 42 U.S.C. section 241(d); 5 U.S.C. section 552a; 44 U.S.C. section 3501 et seq.).All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesData supporting the findings of the study are found in the manuscript and/or supplementary files. Any other data can be furnished upon request.

Background Approximately 67% of U.S. households have pets. Limited data are available on SARS-CoV-2 in pets. We assessed SARS-CoV-2 infection in pet cohabitants as a sub-study of an ongoing COVID-19 household transmission investigation.Methods Mammalian pets from households with ≥1 person with laboratory-confirmed COVID-19 were eligible for inclusion from April–May 2020. Demographic/exposure information, oropharyngeal, nasal, rectal, and fur swabs, feces, and blood were collected from enrolled pets and tested by rRT-PCR and virus neutralization assays.Findings We enrolled 37 dogs and 19 cats from 34 of 41 eligible households. All oropharyngeal, nasal, and rectal swabs tested negative by rRT-PCR; one dog’s fur swabs (2%) tested positive by rRT-PCR at the first animal sampling. Among 47 pets with serological results from 30 households, eight (17%) pets (4 dogs, 4 cats) from 6 (20%) households had detectable SARS-CoV-2 neutralizing antibodies. In households with a seropositive pet, the proportion of people with laboratory-confirmed COVID-19 was greater (median 79%; range: 40–100%) compared to households with no seropositive pet (median 37%; range: 13–100%) (p=0.01). Thirty-three pets with serologic results had frequent daily contact (≥1 hour) with the human index patient before the person’s COVID-19 diagnosis. Of these 33 pets, 14 (42%) had decreased contact with the human index patient after diagnosis and none (0%) were seropositive; of the 19 (58%) pets with continued contact, 4 (21%) were seropositive.Interpretations Seropositive pets likely acquired infection from humans, which may occur more frequently than previously recognized. People with COVID-19 should restrict contact with animals.Funding Centers for Disease Control and Prevention, U.S. Department of AgricultureCompeting Interest StatementThe authors have declared no competing interest.

Olfactory and taste dysfunctions have emerged as symptoms of COVID-19. Among individuals with COVID-19 enrolled in a household study, loss of taste and/or smell was the fourth most commonly reported symptom (26/42; 62%), and among household contacts, it had the highest positive predictive value (83%; 95% CI: 55–95%) for COVID-19. These findings support consideration of loss of taste and/or smell in possible case identification and testing prioritization for COVID-19.Competing Interest StatementThe authors have declared no competing interest.Funding StatementNo external funding was received.Author DeclarationsAll relevant ethical guidelines have been followed; any necessary IRB and/or ethics committee approvals have been obtained and details of the IRB/oversight body are included in the manuscript.YesAll necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesData presented in the current study may be available from the corresponding author on request.

Introduction: Historically, lack of data on cost-effectiveness of influenza vaccination has been identified as a barrier to vaccine use in low- and middle-income countries. We conducted a systematic review of economic evaluations describing (1) costs of influenza illness, (2) costs of influenza vaccination programs, and (3) vaccination cost-effectiveness from low- and middle-income countries to assess if gaps persist. Method(s): We performed a systematic search in Medline, Embase, Cochrane Library, CINAHL, and Scopus using a combination of the following key words: "influenza" AND "cost" OR "economic." The search included studies with publication years 2012 through 2021. We abstracted general study characteristics and data specific to each of the three areas of review. Result(s): Of 50 included studies, 24 presented data on cost-effectiveness, 23 on cost-of-illness, and four on program costs. Represented countries were classified as upper-middle income (UMIC; n=11), lower-middle income (LMIC; n=7), and low-income (LIC; n=3). The most evaluated target groups were children (n=26 studies), older adults (n=16), and persons with chronic medical conditions (n=12); fewer studies evaluated pregnant persons (n=8), healthcare workers (n=4), and persons in congregate living settings (n=1). Costs-of-illness were generally higher in UMICs than in LMICs/LICs; however, the highest total costs, as a percent of gross domestic product and national health expenditure, were reported from an LIC. Among studies that evaluated the cost-effectiveness of influenza vaccine introduction, most (83%) interpreted at least one scenario per target group as either cost-effective or cost-saving, based on thresholds designated in the study. Conclusion(s): Continued evaluation of the economic burden of influenza illness and costs and cost-effectiveness of influenza vaccination, particularly in low-income countries and among underrepresented target groups (e.g., healthcare workers and pregnant persons), is needed; use of standardized methodology could facilitate pooling across settings. Robust, global economic data are critical to design and maintain sustainable influenza vaccination programs. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv 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.

Background: Beginning in March 2021, Mexico vaccinated childcare workers with a single-dose CanSino Biologics (Adv5-nCoV) COVID-19 vaccine. Although CanSino is currently approved for use in 10 Latin American, Asian, and European countries, little information is available about its vaccine effectiveness (VE). Method(s): We evaluated CanSino VE within a childcare worker cohort that included 1,408 childcare facilities. Participants were followed during March-December 2021 and tested through SARS-CoV-2 RT-PCR or rapid antigen test if they developed any symptom compatible with COVID-19. Vaccination status was obtained through worker registries. VE was calculated as 100% x (1-hazard ratio for SARS-CoV-2 infection in fully vaccinated vs. unvaccinated participants), using an Andersen-Gill model adjusted for age, sex, state, and local viral circulation. Result(s): The cohort included 43,925 persons who were mostly (96%) female with a median age of 32 years; 37,646 (86%) were vaccinated with CanSino. During March-December 2021, 2,250 (5%) participants had laboratory-confirmed COVID-19, of whom 25 were hospitalized and 6 died. Adjusted VE was 20% (95% CI = 10-29%) against illness, 76% (42-90%) against hospitalization, and 94% (66-99%) against death. VE against illness declined from 48% (95% CI = 33-61) after 14-60 days following full vaccination to 20% (95% CI = 9-31) after 61-120 days. Conclusion(s): CanSino vaccine was effective at preventing COVID-19 illness and highly effective at preventing hospitalization and death. It will be useful to further evaluate duration of protection and assess the value of booster doses to prevent COVID-19 and severe outcomes. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv 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.

BACKGROUND: Vaccination is one of the most effective measures to prevent influenza illness and its complications; influenza vaccination remained important during the COVID-19 pandemic to prevent additional burden on health systems strained by COVID-19 demand. OBJECTIVES: We describe policies, coverage, and progress of seasonal influenza vaccination programs in the Americas during 2019-2021 and discuss challenges in monitoring and maintaining influenza vaccination coverage among target groups during the COVID-19 pandemic. METHODS: We used data on influenza vaccination policies and vaccination coverage reported by countries/territories via the electronic Joint Reporting Form on Immunization (eJRF) for 2019-2021. We also summarized country vaccination strategies shared with PAHO. RESULTS: As of 2021, 39 (89 %) out of 44 reporting countries/territories in the Americas had policies for seasonal influenza vaccination. Countries/territories adapted health services and immunization delivery strategies using innovative approaches, such as new vaccination sites and expanded schedules, to ensure continuation of influenza vaccination during the COVID-19 pandemic. However, among countries/territories that reported data to eJRF in both 2019 and 2021, median coverage decreased; the percentage point decrease was 21 % (IQR = 0-38 %; n = 13) for healthcare workers, 10 % (IQR = -1.5-38 %; n = 12) for older adults, 21 % (IQR = 5-31 %; n = 13) for pregnant women, 13 % (IQR = 4.8-20.8 %; n = 8) for persons with chronic diseases, and 9 % (IQR = 3-27 %; n = 15) for children. CONCLUSIONS: Countries/territories in the Americas successfully adapted influenza vaccination delivery to continue vaccination services during the COVID-19 pandemic; however, reported influenza vaccination coverage decreased from 2019 to 2021. Reversing declines in vaccination will necessitate strategic approaches that prioritize sustainable vaccination programs across the life course. Efforts should be made to improve the completeness and quality of administrative coverage data. Lessons learned from COVID-19 vaccination, such as the rapid development of electronic vaccination registries and digital certificates, might facilitate advances in coverage estimation.

In 2016, Tanzania expanded sentinel surveillance for influenza-like illness (ILI) and severe acute respiratory infection (SARI) to include testing for non-influenza respiratory viruses (NIRVs) and additional respiratory pathogens at 9 sentinel sites. During 2017-2019, respiratory specimens from 2730 cases underwent expanded testing: 2475 specimens (90.7%) were tested using a U.S. Centers for Disease Control and Prevention (CDC)-developed assay covering 7 NIRVs (respiratory syncytial virus [RSV], rhinovirus, adenovirus, human metapneumovirus, parainfluenza virus 1, 2, and 3) and influenza A and B viruses. Additionally, 255 specimens (9.3%) were tested using the Fast-Track Diagnostics Respiratory Pathogens 33 (FTD-33) kit which covered the mentioned viruses and additional viral, bacterial, and fungal pathogens. Influenza viruses were identified in 7.5% of all specimens; however, use of the CDC assay and FTD-33 kit increased the number of specimens with a pathogen identified to 61.8% and 91.5%, respectively. Among the 9 common viruses between the CDC assay and FTD-33 kit, the most identified pathogens were RSV (22.9%), rhinovirus (21.8%), and adenovirus (14.0%); multi-pathogen co-detections were common. Odds of hospitalization (SARI vs. ILI) varied by sex, age, geographic zone, year of diagnosis, and pathogen identified; hospitalized illnesses were most common among children under the age of 5 years. The greatest number of specimens were submitted for testing during December-April, coinciding with rainy seasons in Tanzania, and several viral pathogens demonstrated seasonal variation (RSV, human metapneumovirus, influenza A and B, and parainfluenza viruses). This study demonstrates that expanding an existing influenza platform to include additional respiratory pathogens can provide valuable insight into the etiology, incidence, severity, and geographic/temporal patterns of respiratory illness. Continued respiratory surveillance in Tanzania, and globally, can provide valuable data, particularly in the context of emerging respiratory pathogens such as SARS-CoV-2, and guide public health interventions to reduce the burden of respiratory illnesses.

BACKGROUND: Beginning in March 2021, Mexico vaccinated childcare workers with a single-dose CanSino Biologics (Adv5-nCoV) COVID-19 vaccine. Although CanSino is currently approved for use in 10 Latin American, Asian, and European countries, little information is available about its vaccine effectiveness (VE). METHODS: We evaluated CanSino VE within a childcare worker cohort that included 1,408 childcare facilities. Participants were followed during March-December 2021 and tested through SARS-CoV-2 RT-PCR or rapid antigen test if they developed any symptom compatible with COVID-19. Vaccination status was obtained through worker registries. VE was calculated as 100% × (1-hazard ratio for SARS-CoV-2 infection in fully vaccinated vs. unvaccinated participants), using an Andersen-Gill model adjusted for age, sex, state, and local viral circulation. RESULTS: The cohort included 43,925 persons who were mostly (96%) female with a median age of 32 years; 37,646 (86%) were vaccinated with CanSino. During March-December 2021, 2,250 (5%) participants had laboratory-confirmed COVID-19, of whom 25 were hospitalized and 6 died. Adjusted VE was 20% (95% CI = 10-29%) against illness, 76% (42-90%) against hospitalization, and 94% (66-99%) against death. VE against illness declined from 48% (95% CI = 33-61) after 14-60 days following full vaccination to 20% (95% CI = 9-31) after 61-120 days. CONCLUSIONS: CanSino vaccine was effective at preventing COVID-19 illness and highly effective at preventing hospitalization and death. It will be useful to further evaluate duration of protection and assess the value of booster doses to prevent COVID-19 and severe outcomes.

Monitoring COVID-19 vaccination coverage among nursing home residents and staff is important to ensure high coverage rates and guide patient-safety policies. With the termination of the federal Pharmacy Partnership for Long-Term Care Program, another source of facility-based vaccination data is needed. We compared numbers of COVID-19 vaccinations administered to nursing home residents and staff reported by pharmacies participating in the temporary federal Pharmacy Partnership for Long-Term Care Program with the numbers of COVID-19 vaccinations reported by nursing homes participating in new COVID-19 vaccination modules of the Centers for Disease Control and Prevention's National Healthcare Safety Network (NHSN). Pearson correlation coefficients comparing the number vaccinated between the 2 approaches were 0.89, 0.96, and 0.97 for residents and 0.74, 0.90, and 0.90 for staff, in the weeks ending January 3, 10, and 17, 2021, respectively. Based on subsequent NHSN reporting, vaccination coverage with ≥1 vaccine dose reached 73.7% for residents and 47.6% for staff the week ending January 31 and increased incrementally through July 2021. Continued monitoring of COVID-19 vaccination coverage is important as new nursing home residents are admitted, new staff are hired, and additional doses of vaccine are recommended.

During July 2021, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) B.1.617.2 variant infections, including vaccine breakthrough infections, occurred after large public gatherings in Provincetown, Massachusetts, USA, prompting a multistate investigation. Public health departments identified primary and secondary cases by using coronavirus disease surveillance data, case investigations, and contact tracing. A primary case was defined as SARS-CoV-2 detected <14 days after travel to or residence in Provincetown during July 3-17. A secondary case was defined as SARS-CoV-2 detected <14 days after close contact with a person who had a primary case but without travel to or residence in Provincetown during July 3-August 10. We identified 1,098 primary cases and 30 secondary cases associated with 26 primary cases among fully and non-fully vaccinated persons. Large gatherings can have widespread effects on SARS-CoV-2 transmission, and fully vaccinated persons should take precautions, such as masking, to prevent SARS-CoV-2 transmission, particularly during substantial or high transmission.

BACKGROUND: After the first of three COVID-19 vaccination clinics in U.S. nursing homes (NHs), the median vaccination coverage of staff was 37.5%, indicating the need to identify strategies to increase staff coverage. We aimed to compare the facility-level activities, policies, incentives, and communication methods associated with higher staff COVID-19 vaccination coverage. METHODS: Design Case-control analysis. Setting Nationally stratified random sample of 1,338 U.S. NHs participating in the Pharmacy Partnership for Long-Term Care Program. Participants Nursing home leadership Measurement During February 4-March 2, 2021, we surveyed NHs with low (<35%), medium (40%-60%) and high (>75%) staff vaccination coverage, to collect information on facility strategies used to encourage staff vaccination. Cases were respondents with medium and high vaccination coverage, whereas controls were respondents with low coverage. We used logistic regression modeling, adjusted for county and NH characteristics, to identify strategies associated with facility-level vaccination coverage. RESULTS: We obtained responses from 413 of 1,338 NHs (30.9%). Compared with facilities with lower staff vaccination coverage, facilities with medium or high coverage were more likely to have designated frontline staff champions (medium: adjusted odds ratio [aOR] 3.6, 95% CI 1.3-10.3; high: aOR 2.9, 95% CI 1.1-7.7) and set vaccination goals (medium: aOR 2.4, 95% 1.0-5.5; high: aOR 3.7, 95% CI 1.6-8.3). NHs with high vaccination coverage were more likely to have given vaccinated staff rewards such as T-shirts compared with NHs with low coverage (aOR 3.8, 95% CI 1.3-11.0). Use of multiple strategies was associated with greater likelihood of facilities having medium or high vaccination coverage: for example, facilities that used ≥9 strategies were three times more likely to have high staff vaccination coverage than facilities using <6 strategies (aOR 3.3, 95% CI 1.2-8.9). CONCLUSIONS: Use of designated champions, setting targets, and use of non-monetary awards, were associated with high NH staff COVID-19 vaccination coverage. This article is protected by copyright. All rights reserved.

Approximately 67% of U.S. households have pets. Limited data are available on SARS-CoV-2 in pets. We assessed SARS-CoV-2 infection in pets during a COVID-19 household transmission investigation. Pets from households with ≥1 person with laboratory-confirmed COVID-19 were eligible for inclusion from April-May 2020. We enrolled 37 dogs and 19 cats from 34 households. All oropharyngeal, nasal, and rectal swabs tested negative by rRT-PCR; one dog's fur swabs (2%) tested positive by rRT-PCR at the first sampling. Among 47 pets with serological results, eight (17%) pets (four dogs, four cats) from 6/30 (20%) households had detectable SARS-CoV-2 neutralizing antibodies. In households with a seropositive pet, the proportion of people with laboratory-confirmed COVID-19 was greater (median 79%; range: 40-100%) compared to households with no seropositive pet (median 37%; range: 13-100%) (p = 0.01). Thirty-three pets with serologic results had frequent daily contact (≥1 h) with the index patient before the person's COVID-19 diagnosis. Of these 33 pets, 14 (42%) had decreased contact with the index patient after diagnosis and none were seropositive; of the 19 (58%) pets with continued contact, four (21%) were seropositive. Seropositive pets likely acquired infection after contact with people with COVID-19. People with COVID-19 should restrict contact with pets and other animals.

OBJECTIVES: In December 2020, CDC launched the Pharmacy Partnership for Long-Term Care Program to facilitate COVID-19 vaccination of residents and staff in long-term care facilities (LTCFs), including assisted living (AL) and other residential care (RC) communities. We aimed to assess vaccine uptake in these communities and identify characteristics that might impact uptake. DESIGN: Cross-sectional study. SETTING AND PARTICIPANTS: AL/RC communities in the Pharmacy Partnership for Long-Term Care Program that had ≥1 on-site vaccination clinic during December 18, 2020-April 21, 2021. METHODS: We estimated uptake by using the cumulative number of doses of COVID-19 vaccine administered and normalizing by the number of AL/RC community beds. We estimated the percentage of residents vaccinated in 3 states using AL census counts. We linked community vaccine administration data with county-level social vulnerability index (SVI) measures to calculate median vaccine uptake by SVI tertile. RESULTS: In AL communities, a median of 67 residents [interquartile range (IQR): 48-90] and 32 staff members (IQR: 15-60) per 100 beds received a first dose of COVID-19 vaccine at the first on-site clinic; in RC, a median of 8 residents (IQR: 5-10) and 5 staff members (IQR: 2-12) per 10 beds received a first dose. Among 3 states with available AL resident census data, median resident first-dose uptake at the first clinic was 93% (IQR: 85-108) in Connecticut, 85% in Georgia (IQR: 70-102), and 78% (IQR: 56-91) in Tennessee. Among both residents and staff, cumulative first-dose vaccine uptake increased with increasing social vulnerability related to housing type and transportation. CONCLUSIONS AND IMPLICATIONS: COVID-19 vaccination of residents and staff in LTCFs is a public health priority. On-site clinics may help to increase vaccine uptake, particularly when transportation may be a barrier. Ensuring steady access to COVID-19 vaccine in LTCFs following the conclusion of the Pharmacy Partnership is critical to maintaining high vaccination coverage among residents and staff.

OBJECTIVE: To evaluate if facility-level vaccination after an initial vaccination clinic was independently associated with COVID-19 incidence adjusted for other factors in January 2021 among nursing home residents. DESIGN: Ecological analysis of data from the CDC's National Healthcare Safety Network (NHSN) and from the CDC's Pharmacy Partnership for Long-Term Care Program. SETTING AND PARTICIPANTS: CMS-certified nursing homes participating in both NHSN and the Pharmacy Partnership for Long-Term Care Program. METHODS: A multivariable, random intercepts, negative binomial model was applied to contrast COVID-19 incidence rates among residents living in facilities with an initial vaccination clinic during the week ending January 3, 2021 (n = 2843), vs those living in facilities with no vaccination clinic reported up to and including the week ending January 10, 2021 (n = 3216). Model covariates included bed size, resident SARS-CoV-2 testing, staff with COVID-19, cumulative COVID-19 among residents, residents admitted with COVID-19, community county incidence, and county social vulnerability index (SVI). RESULTS: In December 2020 and January 2021, incidence of COVID-19 among nursing home residents declined to the lowest point since reporting began in May, diverged from the pattern in community cases, and began dropping before vaccination occurred. Comparing week 3 following an initial vaccination clinic vs week 2, the adjusted reduction in COVID-19 rate in vaccinated facilities was 27% greater than the reduction in facilities where vaccination clinics had not yet occurred (95% confidence interval: 14%-38%, P < .05). CONCLUSIONS AND IMPLICATIONS: Vaccination of residents contributed to the decline in COVID-19 incidence in nursing homes; however, other factors also contributed. The decline in COVID-19 was evident prior to widespread vaccination, highlighting the benefit of a multifaced approach to prevention including continued use of recommended screening, testing, and infection prevention practices as well as vaccination to keep residents in nursing homes safe.

During July 2021, 469 cases of COVID-19 associated with multiple summer events and large public gatherings in a town in Barnstable County, Massachusetts, were identified among Massachusetts residents; vaccination coverage among eligible Massachusetts residents was 69%. Approximately three quarters (346; 74%) of cases occurred in fully vaccinated persons (those who had completed a 2-dose course of mRNA vaccine [Pfizer-BioNTech or Moderna] or had received a single dose of Janssen [Johnson & Johnson] vaccine ≥14 days before exposure). Genomic sequencing of specimens from 133 patients identified the B.1.617.2 (Delta) variant of SARS-CoV-2, the virus that causes COVID-19, in 119 (89%) and the Delta AY.3 sublineage in one (1%). Overall, 274 (79%) vaccinated patients with breakthrough infection were symptomatic. Among five COVID-19 patients who were hospitalized, four were fully vaccinated; no deaths were reported. Real-time reverse transcription-polymerase chain reaction (RT-PCR) cycle threshold (Ct) values in specimens from 127 vaccinated persons with breakthrough cases were similar to those from 84 persons who were unvaccinated, not fully vaccinated, or whose vaccination status was unknown (median = 22.77 and 21.54, respectively). The Delta variant of SARS-CoV-2 is highly transmissible (1); vaccination is the most important strategy to prevent severe illness and death. On July 27, CDC recommended that all persons, including those who are fully vaccinated, should wear masks in indoor public settings in areas where COVID-19 transmission is high or substantial.* Findings from this investigation suggest that even jurisdictions without substantial or high COVID-19 transmission might consider expanding prevention strategies, including masking in indoor public settings regardless of vaccination status, given the potential risk of infection during attendance at large public gatherings that include travelers from many areas with differing levels of transmission.

BACKGROUND: Shigella infections are an important cause of diarrhea in young children and can result in severe complications. Disparities in Shigella infections are well documented among US adults. Our objective was to characterize disparities in incidence and severity of Shigella infections among US children. METHODS: We analyzed laboratory-diagnosed Shigella infections reported to FoodNet, an active, population-based surveillance system in 10 US sites, among children during 2009-2018. We calculated the incidence rate stratified by sex, age, race/ethnicity, Shigella species, and disease severity. Criteria for severe classification were hospitalization, bacteremia, or death. The odds of severe infection were calculated using logistic regression. RESULTS: During 2009-2018, 10 537 Shigella infections were reported in children and 1472 (14.0%) were severe. The incidence rate was 9.5 infections per 100 000 child-years and the incidence rate of severe infections was 1.3 per 100 000 child-years. Incidence was highest among children aged 1-4 years (19.5) and lowest among children aged 13-17 years (2.3); however, children aged 13-17 years had the greatest proportion of severe infections (21.2%). Incidence was highest among Black (16.2 total; 2.3 severe), Hispanic (13.1 total; 2.3 severe), and American Indian/Alaska Native (15.2 total; 2.5 severe) children. Infections caused by non-sonnei species had higher odds of severity than infections caused by Shigella sonnei (adjusted odds ratio 2.58; 95% confidence interval 2.12-3.14). CONCLUSIONS: The incidence and severity of Shigella infections among US children vary by age, race/ethnicity, and Shigella species, warranting investigation of unique risk factors among pediatric subpopulations.

BACKGROUND: In 2018, CDC and the Vermont Department of Health investigated an outbreak of multidrug-resistant Shigella sonnei infections in a retirement community that offered a continuum of care from independent living through skilled nursing care. The investigation identified 24 culture-confirmed cases. Isolates were resistant to trimethoprim-sulfamethoxazole, ampicillin, and ceftriaxone, and had decreased susceptibility to azithromycin and ciprofloxacin. METHODS: To evaluate clinical and microbiologic response, we reviewed inpatient and outpatient medical records for treatment outcomes among the 24 patients with culture-confirmed S. sonnei infection. We defined clinical failure as diarrhea (≥3 loose stools per day) for ≥1 day after treatment finished, and microbiologic failure as a stool culture that yielded S. sonnei after treatment finished. We used broth microdilution to perform antimicrobial susceptibility testing, and whole genome sequencing to identify resistance mechanisms. RESULTS: Isolates contained macrolide resistance genes mph(A) and erm(B) and had azithromycin minimum inhibitory concentrations above the Clinical and Laboratory Standards Institute epidemiological cutoff value of ≤16 µg/mL. Among 24 patients with culture-confirmed Shigella infection, four were treated with azithromycin; all had clinical treatment failure and two also had microbiologic treatment failure. Isolates were susceptible to ciprofloxacin but contained a gyrA mutation; two patients failed treatment with ciprofloxacin. CONCLUSIONS: These azithromycin treatment failures demonstrate the importance of clinical breakpoints to aid clinicians in identifying alternative treatment options for resistant strains. Additionally, these treatment failures highlight a need for comprehensive susceptibility testing and systematic outcome studies, particularly given the emergence of multidrug-resistant Shigella among an expanding range of patient populations.

Compared with other age groups, older adults (defined here as persons aged ≥65 years) are at higher risk for COVID-19-associated morbidity and mortality and have therefore been prioritized for COVID-19 vaccination (1,2). Ensuring access to vaccines for older adults has been a focus of federal, state, and local response efforts, and CDC has been monitoring vaccination coverage to identify and address disparities among subpopulations of older adults (2). Vaccine administration data submitted to CDC were analyzed to determine the prevalence of COVID-19 vaccination initiation among adults aged ≥65 years by demographic characteristics and overall. Characteristics of counties with low vaccination initiation rates were quantified using indicators of social vulnerability data from the 2019 American Community Survey.* During December 14, 2020-April 10, 2021, nationwide, a total of 42,736,710 (79.1%) older adults had initiated vaccination. The initiation rate was higher among men than among women and varied by state. On average, counties with low vaccination initiation rates (<50% of older adults having received at least 1 vaccine dose), compared with those with high rates (≥75%), had higher percentages of older adults without a computer, living in poverty, without Internet access, and living alone. CDC, state, and local jurisdictions in partnerships with communities should continue to identify and implement strategies to improve access to COVID-19 vaccination for older adults, such as assistance with scheduling vaccination appointments and transportation to vaccination sites, or vaccination at home if needed for persons who are homebound.(†) Monitoring demographic and social factors affecting COVID-19 vaccine access for older adults and prioritizing efforts to ensure equitable access to COVID-19 vaccine are needed to ensure high coverage among this group.

Stunting (low height for age) affects approximately one-quarter of children aged < 5 years worldwide. Given the limited impact of current interventions for stunting, new multisectoral evidence-based approaches are needed to decrease the burden of stunting in low- and middle-income countries (LMICs). Recognizing that the health of people, animals, and the environment are connected, we present the rationale and research agenda for considering a One Health approach to child stunting. We contend that a One Health strategy may uncover new approaches to tackling child stunting by addressing several interdependent factors that prevent children from thriving in LMICs, and that coordinated interventions among humans, animals, and environmental health sectors may have a synergistic effect in stunting reduction.

Residents and staff of long-term care facilities (LTCFs) have been prioritized by the Advisory Committee on Immunization Practices for vaccination in the initial COVID-19 vaccine allocation phase in the US.1 Residents and staff of LTCFs, who live and work in congregate settings, are at increased risk for infection with SARS-CoV-2,2 and residents, given their advanced age and/or underlying chronic medical conditions, are at increased risk for severe outcomes.3