Determining Herd Immunity Thresholds for Hepatitis A Virus Transmission to Inform Vaccination Strategies Among People Who Inject Drugs in 16†US States.

BACKGROUND: Widespread outbreaks of person-to-person transmitted hepatitis A virus (HAV), particularly among people who inject drugs (PWID), continue across the United States and globally. However, the herd immunity threshold and vaccination coverage required to prevent outbreaks are unknown. We used surveillance data and dynamic modeling to estimate herd immunity thresholds among PWID in 16 US states. METHODS: We used a previously published dynamic model of HAV transmission calibrated to surveillance data from outbreaks involving PWID in 16 states. Using state-level calibrated models, we estimated the basic reproduction number (R0) and herd immunity threshold for PWID in each state. We performed a meta-analysis of herd immunity thresholds to determine the critical vaccination coverage required to prevent most HAV outbreaks among PWID. RESULTS: Estimates of R0 for HAV infection ranged from 2.2 (95% confidence interval [CI], 1.9-2.5) for North Carolina to 5.0 (95% CI, 4.5-5.6) for West Virginia. Corresponding herd immunity thresholds ranged from 55% (95% CI, 47%-61%) for North Carolina to 80% (95% CI, 78%-82%) for West Virginia. Based on the meta-analysis, we estimated a pooled herd immunity threshold of 64% (95% CI, 61%-68%; 90% prediction interval, 52%-76%) among PWID. Using the prediction interval upper bound (76%) and assuming 95% vaccine efficacy, we estimated that vaccination coverage of 80% could prevent most HAV outbreaks. CONCLUSIONS: Hepatitis A vaccination programs in the United States may need to achieve vaccination coverage of at least 80% among PWID in order to prevent most HAV outbreaks among this population.

Effectiveness of patient reminders on influenza vaccination coverage among adults with chronic conditions: A feasibility study in Australian general practices.

BACKGROUND: Influenza vaccination is recommended for Australians 18+ years old with medical risk factors, but coverage is suboptimal. We aimed to examine whether automatic, opportunistic patient reminders (SMS and/or printed) before appointments with a general practitioner increased influenza vaccination uptake. METHODS: This clustered non-randomised feasibility study in Australian general practice included patients aged 18-64 years with at least one medical risk factor attending participating practices between May and September 2021. Software installed at intervention practices identified unvaccinated eligible patients when they booked an appointment, sent vaccination reminders (SMS on booking and 1 h before appointments), and printed automatic reminders on arrival. Control practices provided usual care. Clustered analyses adjusted for sociodemographic differences among practices were performed using logistic regression. RESULTS: A total of 12,786 at-risk adults attended 16 intervention practices (received reminders = 4066; 'internal control' receiving usual care = 8720), and 5082 individuals attended eight control practices. Baseline influenza vaccination uptake (2020) was similar in intervention and control practices (∼34%). After the intervention, uptake was similar in all groups (control practices = 29.3%; internal control = 30.0%; intervention = 31.6% (p-value = 0.203). However, SMS 1 h before appointments increased vaccination coverage (39.3%, adjusted OR = 1.65; 95%CI 1.20;2.27; number necessary to treat = 13), especially when combined with other reminder forms. That effect was more evident among adults with chronic respiratory, rheumatologic, or inflammatory bowel disease. CONCLUSION: These findings indicate that automated SMS reminders delivered at proximate times to appointments are a low-cost strategy to increase influenza vaccination among adults at higher risk of severe disease attending Australian general practices.

Challenges in assessing the immunization status of adults in Germany-lessons from a population-based VACCELERATE survey on polio vaccination.

PURPOSE: Considering the re-emergence of poliomyelitis (PM) in non-endemic regions, it becomes apparent that vaccine preventable diseases can rapidly develop epi- or even pandemic potential. Evaluation of the current vaccination status is required to inform patients, health care providers and policy makers about vaccination gaps. METHODS: Between October 28 2022 and November 23 2022, 5,989 adults from the VACCELEREATE Volunteer Registry completed an electronic case report form on their previous PM vaccine doses including number, types/-valencies and the time of administration based on their vaccination records. A uni-/multivariable regression analysis was performed to assess associations in participant characteristics and immunization status. RESULTS: Among German volunteers (n = 5,449), complete PM immunization schedule was found in 1,981 (36%) participants. Uncertain immunization, due to unknown previous PM vaccination (n = 313, 6%), number of doses (n = 497, 9%), types/-valencies (n = 1,233, 23%) or incoherent immunization schedule (n = 149, 3%) was found in 40% (n = 2,192). Out of 1,276 (23%) participants who reported an incomplete immunization schedule, 62 (1%) never received any PM vaccine. A total of 5,074 (93%) volunteers reported having been vaccinated at least once and 2,087 (38%) indicated that they received vaccination within the last ten years. Female sex, younger age, as well as availability of first vaccination record were characteristics significantly associated with complete immunization (p < 0.001). CONCLUSION: Full PM immunization schedule was low and status frequently classified as uncertain due to lack of details on administered doses. There is an obviousneed for improved recording to enable long-term access to detailed vaccination history in the absence of a centralized immunization register.

Predictors of COVID-19 vaccine uptake: an online three-wave survey study of US adults.

BACKGROUND: To effectively promote vaccine uptake, it is important to understand which people are most and least inclined to be vaccinated and why. In this study, we examined predictors of COVID-19 vaccine uptake and reasons for non-vaccination. METHODS: We conducted an online English-language survey study in December-2020, January-2021, and March-2021. A total of 930 US respondents completed all surveys. Multiple logistic regression models were run to test whether the early vaccine eligibility, demographic factors, and psychological factors predict getting at least one dose of a COVID-19 vaccination in January-2021 and in March-2021. RESULTS: The proportion of respondents who received ≥ 1-dose of a COVID-19 vaccine increased from 18% (January) to 67% (March). Older age predicted vaccine uptake in January (OR = 2.02[95%CI = 1.14-3.78], p < .001) and March (10.92[6.76-18.05], p < .001). In January, additional predictors were higher numeracy (1.48[1.20-1.86], p < .001), COVID-19 risk perceptions (1.35[1.03-1.78], p = .029), and believing it is important adults get the COVID-19 vaccine (1.66[1.05-2.66], p = .033). In March, additional predictors of uptake were believing it is important adults get the COVID-19 vaccine (1.63[1.15-2.34], p = .006), prior COVID-19 vaccine intentions (1.37[1.10-1.72], p = .006), and belief in science (0.84[0.72-0.99], p = .041). Concerns about side effects and the development process were the most common reasons for non-vaccination. Unvaccinated respondents with no interest in getting a COVID-19 vaccine were younger (0.27[0.09-0.77], p = .016), held negative views about COVID-19 vaccines for adults (0.15[0.08-0.26], p < .001), had lower trust in healthcare (0.59[0.36-0.95], p = .032), and preferred to watch and wait in clinically ambiguous medical situations (0.66[0.48-0.89], p = .007). CONCLUSIONS: Evidence that attitudes and intentions towards COVID-19 vaccines were important predictors of uptake provides validation for studies using these measures and reinforces the need to develop strategies for addressing safety and development concerns which remain at the forefront of vaccine hesitancy.

Assessing New York City's COVID-19 Vaccine Rollout Strategy: A Case for Risk-Informed Distribution.

This study reviews the impact of eligibility policies in the early rollout of the COVID-19 vaccine on coverage and probable outcomes, with a focus on New York City. We conducted a retrospective ecological study assessing age 65+, area-level income, vaccination coverage, and COVID-19 mortality rates, using linked Census Bureau data and New York City Health administrative data aggregated at the level of modified zip code tabulation areas (MODZCTA). The population for this study was all individuals in 177 MODZCTA in New York City. Population data were obtained from Census Bureau and New York City Health administrative data. The total mortality rate was examined through an ordinary least squares (OLS) regression model, using area-level wealth, the proportion of the population aged 65 and above, and the vaccination rate among this age group as predictors. Low-income areas with high proportions of older people demonstrated lower coverage rates (mean vaccination rate 52.8%; maximum coverage 67.9%) than wealthier areas (mean vaccination rate 74.6%; maximum coverage 99% in the wealthiest quintile) in the first 3 months of vaccine rollout and higher mortality over the year. Despite vaccine shortages, many younger people accessed vaccines ahead of schedule, particularly in high-income areas (mean coverage rate 60% among those 45-64 years in the wealthiest quintile). A vaccine program that prioritized those at greatest risk of COVID-19-associated morbidity and mortality would have prevented more deaths than the strategy that was implemented. When rolling out a new vaccine, policymakers must account for local contexts and conditions of high-risk population groups. If New York had focused limited vaccine supply on low-income areas with high proportions of residents 65 or older, overall mortality might have been lower.

Public health and economic benefits of seasonal influenza vaccination in risk groups in France, Italy, Spain and the UK: state of play and perspectives.

BACKGROUND: Seasonal influenza epidemics have a substantial public health and economic burden, which can be alleviated through vaccination. The World Health Organization (WHO) recommends a 75% vaccination coverage rate (VCR) in: older adults (aged ≥ 65 years), individuals with chronic conditions, pregnant women, children aged 6-24 months and healthcare workers. However, no European country achieves this target in all risk groups. In this study, potential public health and economic benefits achieved by reaching 75% influenza VCR was estimated in risk groups across four European countries: France, Italy, Spain, and the UK. METHODS: A static epidemiological model was used to estimate the averted public health and economic burden of increasing the 2021/2022 season VCR to 75%, using the efficacy data of standard-dose quadrivalent influenza vaccine. For each country and risk group, the most recent data on population size, VCR, pre-pandemic influenza epidemiology, direct medical costs and absenteeism were identified through a systematic literature review, supplemented by manual searching. Outcomes were: averted influenza cases, general practitioner (GP) visits, hospitalisations, case fatalities, number of days of work lost, direct medical costs and absenteeism-related costs. RESULTS: As of the 2021/2022 season, the UK achieved the highest weighted VCR across risk groups (65%), followed by Spain (47%), France (44%) and Italy (44%). Based on modelling, the 2021/2022 VCR prevented an estimated 1.9 million influenza cases, avoiding 375,200 GP visits, 73,200 hospitalisations and 38,400 deaths. To achieve the WHO 75% VCR target, an additional 24 million at-risk individuals would need to be vaccinated, most of which being older adults and patients with chronic conditions. It was estimated that this could avoid a further 918,200 influenza cases, 332,000 GP visits, 16,300 hospitalisations and 6,300 deaths across the four countries, with older adults accounting for 52% of hospitalisations and 80% of deaths. An additional €84 million in direct medical costs and €79 million in absenteeism costs would be saved in total, with most economic benefits delivered in France. CONCLUSIONS: Older adults represent most vaccine-preventable influenza cases and deaths, followed by individuals with chronic conditions. Health authorities should prioritise vaccinating these populations for maximum public health and economic benefits.

Assessing the impact of COVID-19 on routine immunization in Sierra Leone.

BACKGROUND: The COVID-19 pandemic had a profound impact on healthcare systems and services, including routine immunization (RI). To date, there is limited information on the effects of the COVID-19 pandemic on RI in West African countries such as Sierra Leone, which had already experienced public health emergencies that disrupted its healthcare system. Here, we describe the impact of the COVID-19 pandemic on the RI of key antigens in Sierra Leone. METHODS: We used vaccination data from the District Health Information System for BCG, measles-rubella 1 and 2, and pentavalent 1 and 3 antigens. We compared 2019, 2020, 2021, and 2022 annual coverage rates for the selected antigens at the national and district levels. We used the Pearson chi-square test to assess the difference between annual coverage rates between 2019 and 2020, 2020-2021, and 2021-2022. RESULTS: National coverage rates for all antigens declined in 2019-2020, notably measles-rubella 1 and pentavalent 3 (-5.4% and - 4.9%). Between 2020 and 2021, there was an overall increase in coverage (+ 0.2% to + 2.5%), except for measles-rubella 2 (-1.8%). Measles-rubella antigens rebounded in 2021-2022, while others decreased between - 0.5 and - 1.9% in coverage. Overall, all district-level coverage rates in 2022 were lower than those in 2019. Most districts decreased between 2019 and 2022, though a few had a continuous increase; some had an increase/recovery between 2020 and 2021; some districts had recovered 2019 levels by 2022. CONCLUSION: The COVID-19 pandemic impacted Sierra Leone's national BCG, measles-rubella, and pentavalent antigen immunization, which were not fully restored in 2022. Most districts experienced notable coverage declines during the pandemic, though a few reached or surpassed 2019 rates in 2022. Examining pandemic impact can benefit from a focus beyond the national level to identify vulnerable regions. Sierra Leone's post-pandemic RI reestablishment needs targeted strategies and continual investments for equitable access and coverage, as well as to prevent vaccine-preventable diseases.

The impact of the COVID-19 vaccination programme on symptomatic and severe SARS-CoV-2 infection during a period of Omicron variant dominance in Ireland, December 2021 to March 2023.

BackgroundAs Ireland prepared for an autumn 2023 COVID-19 vaccination booster campaign, there was concern that vaccine fatigue would affect uptake, which has been abating.AimThis study aimed to quantify the direct impact of the COVID-19 vaccination programme in Ireland on averted COVID-19-related outcomes including symptomatic presentations to primary care/community testing centres, emergency department (ED) presentations, hospitalisations, intensive care unit (ICU) admissions and deaths, in individuals aged ≥ 50 years, during Omicron dominance.MethodsWe conducted a retrospective observational COVID-19 vaccine impact study in December 2021-March 2023 in Ireland. We used national data on notified outcomes and vaccine coverage, as well as vaccine effectiveness (VE) estimates, sourced from the World Health Organization's live systematic review of VE, to estimate the count and prevented fraction of outcomes in ≥ 50-year-olds averted by the COVID-19 vaccination programme in this age group.ResultsThe COVID-19 vaccination programme averted 48,551 symptomatic COVID-19 presentations to primary care/community testing centres (36% of cases expected in the absence of vaccination), 9,517 ED presentations (53% of expected), 102,160 hospitalisations (81% of expected), 3,303 ICU admissions (89% of expected) and 15,985 deaths (87% of expected).ConclusionsWhen Omicron predominated, the COVID-19 vaccination programme averted symptomatic and severe COVID-19 cases, including deaths due to COVID-19. In line with other international vaccine impact studies, these findings emphasise the benefits of COVID-19 vaccination for population health and the healthcare system and are relevant for informing COVID-19 booster vaccination programmes, pandemic preparedness and communicating the reason for and importance of COVID-19 vaccination in Ireland and internationally.

Seroprevalence of tick-borne encephalitis virus and vaccination coverage of tick-borne encephalitis, Sweden, 2018 to 2019.

BackgroundIn Sweden, information on seroprevalence of tick-borne encephalitis virus (TBEV) in the population, including vaccination coverage and infection, is scattered. This is largely due to the absence of a national tick-borne encephalitis (TBE) vaccination registry, scarcity of previous serological studies and use of serological methods not distinguishing between antibodies induced by vaccination and infection. Furthermore, the number of notified TBE cases in Sweden has continued to increase in recent years despite increased vaccination.AimThe aim was to estimate the TBEV seroprevalence in Sweden.MethodsIn 2018 and 2019, 2,700 serum samples from blood donors in nine Swedish regions were analysed using a serological method that can distinguish antibodies induced by vaccination from antibodies elicited by infection. The regions were chosen to reflect differences in notified TBE incidence.ResultsThe overall seroprevalence varied from 9.7% (95% confidence interval (CI): 6.6-13.6%) to 64.0% (95% CI: 58.3-69.4%) between regions. The proportion of vaccinated individuals ranged from 8.7% (95% CI: 5.8-12.6) to 57.0% (95% CI: 51.2-62.6) and of infected from 1.0% (95% CI: 0.2-3.0) to 7.0% (95% CI: 4.5-10.7). Thus, more than 160,000 and 1,600,000 individuals could have been infected by TBEV and vaccinated against TBE, respectively. The mean manifestation index was 3.1%.ConclusionA difference was observed between low- and high-incidence TBE regions, on the overall TBEV seroprevalence and when separated into vaccinated and infected individuals. The estimated incidence and manifestation index argue that a large proportion of TBEV infections are not diagnosed.

[Brazilian Ministry of Health strategy to increase vaccination coverage at bordersEstrategia del Ministerio de Salud de Brasil para aumentar las tasas de cobertura de vacunación en las fronteras]. / Estratégia do Ministério da Saúde do Brasil para aumento das coberturas vacinais nas fronteiras.

Objective: Evaluate the implementation of the Ministry of Health's "Action Plan: Border Vaccination Strategy - Agenda 2022" in the Brazil's 33 twin cities and evaluate the increase in the country's vaccination coverage (VC). Methodology: Pre-post community clinical trial. Implementation of the strategy was analyzed, and pre- and post-intervention VC were compared in two stages: P1 (pre-intervention) and P2 (post-intervention). Based on statistical analyses of P1 and P2 coverage, calculations were made of municipal averages, standard deviation, and difference in VC between the two periods. Results: Integration was observed between the primary health care (PHC), surveillance, immunization, and special indigenous health district (DSEI) teams, although there were difficulties, for example, in relation to migratory flows. While immigration flows present challenges in the areas of immunization, PHC, and DSEI, the difficulties are compounded by the polarization of these services, which hinders intersectoral integration. After carrying out the workshops, a total of 50 977 doses were administered in the general population in the 33 twin cities. There was an increase in vaccination coverage in children up to 1 year of age in the locations evaluated after the intervention, which may be relevant in terms of increasing VC in Brazil. Conclusion: There was an increase in vaccination coverage in children up to 1 year of age in the locations evaluated after the intervention, helping to increase VC in Brazil.

Objetivo: Evaluar la aplicación de la Estrategia de Vacunación en las Fronteras - Agenda 2022, que forma parte del Plan de Acción del Ministerio de Salud en las 33 ciudades hermanas y evaluar el aumento de las tasas de cobertura de vacunación en Brasil. Métodos: Ensayo clínico comunitario realizado antes y después de la intervención correspondiente. Se analizó la aplicación de la estrategia y se compararon las tasas de cobertura de vacunación antes y después de la intervención en dos periodos: P1 (pre-intervención) y P2 (post-intervención). En los análisis estadísticos de la tasa de cobertura de vacunación en P1 y P2 se calcularon los valores de media y desviación estándar de los municipios y la diferencia entre las tasas de cobertura de los dos periodos. Resultados: Se observó una integración entre los equipos de Atención Primaria de Salud, Vigilancia, Inmunización y el Distrito Especial de Salud Indígena (DISEI), pero con dificultades, como las inherentes al flujo migratorio. Cabe destacar que el flujo migratorio es uno de los desafíos en el contexto de la inmunización, la atención primaria de salud y el DISEI, dificultad que se ve agravada por la polarización entre los servicios (inmunización, atención primaria de salud y el DISEI), lo que supone un reto para la integración de los sectores. Por lo que respecta al análisis de las tasas de cobertura de vacunación llevado a cabo después de realizar los talleres, se administró un total de 50 977 dosis a la población general en las 33 ciudades hermanas de Brasil. Hubo un aumento de las tasas de cobertura de vacunación de menores de hasta un año de edad en los lugares evaluados después de la intervención, lo que puede ser importante para aumentar las tasas de cobertura de Brasil. Conclusión: Después de la intervención hubo un aumento de las tasas de cobertura de vacunación de menores de hasta un año de edad en los lugares evaluados, lo cual influyó en el incremento de las tasas de cobertura de Brasil.

Maintaining the Region of the Americas free of polio: best practices for incident management support teams.

The Pan American Health Organization (PAHO) and its Member States have been leading the efforts to eradicate wild poliovirus in the Region of Americas since smallpox's successful elimination in 1971. The region became the first to be certified free of wild poliovirus in 1994. However, in July 2022, an unvaccinated patient with no recent travel history was diagnosed with poliomyelitis in the United States of America. In response to the emergence of a circulating vaccine-derived poliovirus in the United States, PAHO established the Polio Incident Management Support Team. This team has been coordinating response efforts, focusing on: coordination, planning, and monitoring; risk communication and community engagement; surveillance and case investigation; vaccination; and rapid response. In this paper, we identified and documented best practices observed following establishment of the Incident Management Support Team (September 2022-2023) through a comprehensive review and analysis of various data sources and country-specific data from the polio surveillance dashboard. The aim was to share these best practices, highlighting technical support and implementation of polio measures by Member States. Despite several challenges, the Americas region remains polio-free. Polio risk is declining, with a July 2023 assessment showing fewer countries at medium, high, and very high risk. This progress reflects improved immunization coverage, surveillance, containment, health determinants, and outbreak preparedness and response. The PAHO Polio Incident Management Support Team has played a key role in supporting these efforts.

La Organización Panamericana de la Salud (OPS) y sus Estados Miembros han liderado los esfuerzos para erradicar el poliovirus salvaje en la Región de las Américas desde la eliminación exitosa de la viruela en 1971. En 1994, la Región fue la primera en obtener la certificación de libre del poliovirus salvaje. Sin embargo, en julio del 2022, se diagnosticó poliomielitis a un paciente de Estados Unidos de América no vacunado y sin antecedentes de viajes recientes. Para responder a la aparición de un poliovirus circulante derivado de la vacuna en ese país, la OPS creó el equipo de apoyo a la gestión de incidentes de poliomielitis. Este equipo ha asumido la coordinación de los esfuerzos de respuesta y se ha centrado en la coordinación, la planificación y seguimiento; la comunicación de riesgos y la participación de la comunidad; la vigilancia e investigación de casos; la vacunación; y la respuesta rápida. En este artículo, se determinan y documentan las mejores prácticas observadas después de la creación del equipo de apoyo a la gestión de incidentes (septiembre del 2022-2023) mediante una revisión y un análisis pormenorizados de datos procedentes de diversas fuentes y de datos específicos de los países del panel de vigilancia de la poliomielitis. El objetivo fue poner en común estas mejores prácticas y resaltar el apoyo técnico y la aplicación de medidas contra la poliomielitis por parte de los Estados Miembros. A pesar de los diversos desafíos, la Región de las Américas se mantiene libre de poliomielitis. El riesgo de esta enfermedad es cada vez menor, y la evaluación de julio del 2023 muestra una disminución del número de países con un riesgo medio, alto o muy alto. Este progreso refleja la mejora de la cobertura de inmunización, la vigilancia, la contención, los determinantes de la salud y la preparación y respuesta ante brotes. El equipo de apoyo a la gestión de incidentes relacionados con la poliomielitis de la OPS ha desempeñado un papel fundamental para brindar apoyo a estas iniciativas.

Desde a eliminação bem-sucedida da varíola em 1971, a Organização Pan-Americana da Saúde (OPAS) e seus Estados Membros têm estado à frente de iniciativas para erradicar o poliovírus selvagem na Região das Américas. Em 1994, a região foi a primeira do mundo a ser certificada como livre do poliovírus selvagem. Entretanto, em julho de 2022, um paciente não vacinado e sem histórico de viagens recentes foi diagnosticado com poliomielite nos Estados Unidos da América. Em resposta ao surgimento de um poliovírus derivado de vacina circulante nos Estados Unidos, a OPAS criou a Equipe de Apoio à Gestão de Incidentes de Poliomielite. A equipe vem administrando os esforços de resposta, concentrando-se em: coordenação, planejamento e monitoramento; comunicação de risco e envolvimento da comunidade; vigilância e investigação de casos; vacinação; e resposta rápida. Neste documento, identificamos e documentamos as melhores práticas observadas após a criação da Equipe de Apoio à Gestão de Incidentes (setembro de 2022 a 2023) por meio de uma revisão e análise abrangentes de diversas fontes de dados e dados específicos de cada país fornecidos por meio do painel de vigilância da poliomielite. O objetivo foi compartilhar essas melhores práticas, destacando o apoio técnico e a implementação de medidas contra a poliomielite pelos Estados Membros. Apesar de vários desafios, a Região das Américas continua livre da poliomielite. Um levantamento de julho de 2023 demonstrou que o risco da poliomielite vem diminuindo, com menos países com risco médio, alto ou muito alto. Essa evolução é resultado de melhoras na cobertura vacinal, vigilância, contenção, preparação, determinantes de saúde e resposta a surtos. A Equipe de Apoio à Gestão de Incidentes de Poliomielite da OPAS foi fundamental para apoiar esses esforços.

Strategies for expanding childhood vaccination in the Americas following the COVID-19 pandemic.

Objective: To provide an overview of the status of the childhood vaccination schedule in the Americas, outline program structures, and identify updated implementation strategies to improve vaccination coverage following the COVID-19 pandemic. Methods: A group of experts in pediatrics, epidemiology, vaccines, and global and public health discussed the current status of the childhood vaccination schedule in the Americas, describing the program structure and identifying new implementation strategies that have the potential to improve vaccination coverage in the post-pandemic context, after the challenges COVID-19 presented for more than two years. Results: The Americas currently face a high risk of resurgence of diseases that were previously controlled or eliminated. Therefore, it is important to find new strategies to educate citizens on the risks associated with lower vaccination rates, especially in children. Conclusions: New strategies along with strong mobilization of the population and advocacy by citizens are necessary to prevent antivaccination groups from gaining a stronger presence in the region and jeopardizing the credibility of the Expanded Program on Immunization.

[Ranking of immunization programs in Latin America, 2020Ranking dos programas de vacinação na América Latina, 2020]. / Ranking de los programas de vacunación en América Latina, 2020.

Objective: Construct a ranking of national immunization programs in Latin America in 2020 and compare it with the previous year. Methods: Eighteen national immunization programs were evaluated on the basis of public information obtained from official sites of the countries' ministries of health, the World Health Organization, the Pan American Health Organization, the United Nations Children's Fund, and local sources. The ranking was based on the 2020 vaccination schedule for different life stages, special situations, vaccination against influenza, 2019 vaccination coverage, and programmatic aspects. Results: Vaccination coverage decreased in most countries. The average regional declined in 2020, as did the scores for most countries, except Chile and Colombia. Chile leads the ranking, followed by Uruguay, Panama, and Costa Rica. Chile stands out for its full calendar, higher vaccination coverage rates, and programmatic achievements. Conclusions: The lower overall score in 2020 highlights the need to recover the Region's vaccination coverage rates. This analysis seeks to motivate countries to address pending challenges.

Objetivo: Construir e comparar o ranking dos programas nacionais de imunização (PNIs) na América Latina em 2020 com o ano anterior. Métodos: Foram avaliados 18 PNIs com base em informações públicas obtidas de sites oficiais dos ministérios da Saúde dos países, da Organização Mundial da Saúde, da Organização Pan-Americana da Saúde, do Fundo das Nações Unidas para a Infância e de fontes locais. O ranking foi compilado com base no calendário de vacinação de 2020 para diferentes fases da vida, situações especiais, vacinação contra a gripe, cobertura vacinal (CV) de 2019 e aspectos programáticos. Resultados: As CVs diminuíram na maioria dos países. A pontuação média regional e a pontuação da maioria dos países também caíram em 2020, exceto no Chile e na Colômbia. O Chile lidera o ranking, seguido do Uruguai, do Panamá e da Costa Rica, e se destaca por ter um calendário completo, maiores CVs e êxitos programáticos. Conclusões: A pontuação global mais baixa em 2020 destaca a necessidade de recuperar a CV da região. Esta análise busca motivar os países a enfrentar os desafios pendentes.

Anti-rubella seroprevalence assessment in an adult sample population in Italy.

Introduction: Despite global immunization efforts, rubella remains a public health concern, particularly in high- and middle-income countries. This study focused on rubella seroprevalence in the province of Florence, Italy, aiming to identify susceptibility clusters, especially among women in their childbearing age. Methods: A cross-sectional study was conducted between April 2018 and December 2019, enrolling 430 adult subjects (age over 18 years). Serum samples were collected, and anti-rubella antibodies were quantified using the ELISA test. Data were analyzed descriptively and compared by sex, nationality, and age groups using statistical tests. Results: The overall rubella seroprevalence was high (92.3%), with no significant differences between genders or nationalities. Among childbearing-age females (18-49 years), the highest seroprevalence was observed in the 30-39 age group (94.1%). However, susceptibility clusters exceeding the 5% threshold set by WHO were identified, especially in females aged 40-49 years (7.0%). Conclusions: Despite high overall seroprevalence, the study identified pockets of susceptibility, even in childbearing age women. Continuous monitoring, targeted immunization strategies, and public health interventions are recommended to maintain rubella elimination, emphasizing the importance of sustained vaccination efforts to protect vulnerable populations.

[Vaccination status and factors associated with pneumococcal vaccination in geriatric short-stay care]. / Statut vaccinal et facteurs associés à la vaccination antipneumococcique en court séjour gériatrique.

Nearly two-thirds of geriatric short-stay patients were eligible for pneumococcal vaccination. Among patients eligible for vaccination, less than 5 % had received at least one injection of pneumococcal vaccine on admission. We found no modifiable factors associated with vaccination status, but several avenues for improving vaccination coverage.

Relationships Between Social Vulnerability and Coronavirus Disease 2019 Vaccination Coverage and Vaccine Effectiveness.

BACKGROUND: Coronavirus disease 2019 (COVID-19) vaccination coverage remains lower in communities with higher social vulnerability. Factors such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exposure risk and access to healthcare are often correlated with social vulnerability and may therefore contribute to a relationship between vulnerability and observed vaccine effectiveness (VE). Understanding whether these factors impact VE could contribute to our understanding of real-world VE. METHODS: We used electronic health record data from 7 health systems to assess vaccination coverage among patients with medically attended COVID-19-like illness. We then used a test-negative design to assess VE for 2- and 3-dose messenger RNA (mRNA) adult (≥18 years) vaccine recipients across Social Vulnerability Index (SVI) quartiles. SVI rankings were determined by geocoding patient addresses to census tracts; rankings were grouped into quartiles for analysis. RESULTS: In July 2021, primary series vaccination coverage was higher in the least vulnerable quartile than in the most vulnerable quartile (56% vs 36%, respectively). In February 2022, booster dose coverage among persons who had completed a primary series was higher in the least vulnerable quartile than in the most vulnerable quartile (43% vs 30%). VE among 2-dose and 3-dose recipients during the Delta and Omicron BA.1 periods of predominance was similar across SVI quartiles. CONCLUSIONS: COVID-19 vaccination coverage varied substantially by SVI. Differences in VE estimates by SVI were minimal across groups after adjusting for baseline patient factors. However, lower vaccination coverage among more socially vulnerable groups means that the burden of illness is still disproportionately borne by the most socially vulnerable populations.

COVID-19 Epidemiology during Delta Variant Dominance Period in 45 High-Income Countries, 2020-2021.

The SARS-CoV-2 Delta variant, first identified in October 2020, quickly became the dominant variant worldwide. We used publicly available data to explore the relationship between illness and death (peak case rates, death rates, case-fatality rates) and selected predictors (percentage vaccinated, percentage of the population >65 years, population density, testing volume, index of mitigation policies) in 45 high-income countries during the Delta wave using rank-order correlation and ordinal regression. During the Delta-dominant period, most countries reported higher peak case rates (57%) and lower peak case-fatality rates (98%). Higher vaccination coverage was protective against peak case rates (odds ratio 0.95, 95% CI 0.91-0.99) and against peak death rates (odds ratio 0.96, 95% CI 0.91-0.99). Vaccination coverage was vital to preventing infection and death from COVID-19 during the Delta wave. As new variants emerge, public health authorities should encourage the uptake of COVID-19 vaccination and boosters.

COVID-19 Booster Dose Vaccination Coverage and Factors Associated with Booster Vaccination among Adults, United States, March 2022.

The Centers for Disease Control and Prevention recommends a COVID-19 vaccine booster dose for all persons >18 years of age. We analyzed data from the National Immunization Survey-Adult COVID Module collected during February 27-March 26, 2022 to assess COVID-19 booster dose vaccination coverage among adults. We used multivariable logistic regression analysis to assess factors associated with vaccination. COVID-19 booster dose coverage among fully vaccinated adults increased from 25.7% in November 2021 to 63.4% in March 2022. Coverage was lower among non-Hispanic Black (52.7%), and Hispanic (55.5%) than non-Hispanic White adults (67.7%). Coverage was 67.4% among essential healthcare personnel, 62.2% among adults who had a disability, and 69.9% among adults who had medical conditions. Booster dose coverage was not optimal, and disparities by race/ethnicity and other factors are apparent in coverage uptake. Tailored strategies are needed to educate the public and reduce disparities in COVID-19 vaccination coverage.

HPV vaccination coverage and factors among American Indians in Cherokee Nation.

PURPOSE: We estimated human papillomavirus (HPV) vaccine initiation coverage among American Indian adolescents and identified factors associated with HPV vaccination among parents of these adolescents. METHODS: We developed, tested, and disseminated a survey to a random sample of 2,000 parents of American Indian adolescents aged 9-17 years who had accessed Cherokee Nation Health Services from January 2019 to August 2020. We used log-binomial regression to estimate the unadjusted and adjusted weighted prevalence proportion ratios (PPR) and 95% confidence intervals (CI) for adolescent HPV vaccine initiation. RESULTS: HPV vaccine initiation coverage (≥ 1 dose) was 70.7% among adolescents aged 13-17 years. The prevalence of HPV vaccine initiation was higher among American Indian adolescents whose parents were aware of the HPV vaccine (adjusted weighted PPR 3.41; 95% CI 2.80, 4.15) and whose parents received a recommendation from their provider (adjusted weighted PPR 2.70; 95% CI 2.56, 2.84). The most common reasons reported by parents to vaccinate their children were to protect them against HPV-associated cancers (25.7%) and receiving a recommendation from a healthcare provider (25.0%). Parents cited vaccine safety concerns as the main reason for not getting their children vaccinated (33.2%). CONCLUSIONS: HPV vaccine initiation coverage among American Indian adolescents in Cherokee Nation was consistent with the national survey estimates. However, allaying parental concerns about vaccine safety and encouraging providers to recommend the HPV vaccine could improve coverage.

Increasing influenza vaccination coverage in healthcare workers: analysis of an intensified on-site vaccination campaign during the COVID-19 pandemic.

PURPOSE: Influenza infections have substantial impact on healthcare institutions. While vaccination is the most effective preventive measure against influenza infection, vaccination coverage in healthcare workers is low. The study investigates the impact of an intensified influenza vaccination campaign in a maximum-care hospital on influenza vaccination coverage in healthcare workers during the COVID-19 pandemic in 2020/21. METHODS: Building on findings from our previously published review Schumacher et al. (Infection 49(3): 387, 2021), an intensified influenza vaccination campaign comprising a mobile vaccination team providing on-site vaccination and vaccination at a recurring central vaccination site in addition to promotional measures was performed and analysed regarding vaccination coverage. A survey querying vaccination motivation was performed. Campaign strategies and vaccination coverage of influenza seasons between 2017/18 and 2019/20 were analysed. RESULTS: The influenza vaccination campaign 2020/21 led to a significant 2.4-fold increase yielding an overall vaccination coverage of 40% among healthcare workers. A significant increase in vaccination coverage was observed across all professional fields; especially among nurses, a 2.7-fold increase, reaching a vaccination coverage of 48%, was observed. The COVID-19 pandemic positively influenced vaccination decision in 72% of first time ever or first time in over ten years influenza vaccinees. Vaccination coverage during prior vaccination campaigns focusing on educational measures did not exceed 17%. CONCLUSION: A mobile vaccination team providing on-site vaccination and vaccinations at a central vaccination site in addition to promotional measures can be implemented to increase influenza vaccination coverage in healthcare workers. Our concept can inform influenza and other vaccination campaigns for healthcare workers.