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.

[Space-time heterogeneity of measles, mumps, and rubella vaccination indicators in children from BrazilHeterogeneidad espaciotemporal de los indicadores de inmunización con la vacuna triple viral en la población infantil de Brasil]. / Heterogeneidade espaço-temporal dos indicadores de imunização da vacina tríplice viral em crianças no Brasil.

Objective: To evaluate immunization coverage and dropout rates of the measles, mumps, and rubella vaccine across Brazilian regions. Methods: This ecological study employing a space-time approach used data from the National Immunization Program (PNI) and the Live Births Information System (SINASC). We estimated the annual variation (2014 to 2021) in immunization coverage and dropout rate of the measles, mumps, and rubella vaccine in children aged 12 and 15 months in the 5 570 Brazilian municipalities. Statistical analysis was conducted for the municipalities contained in each Brazilian region using the space-time scan technique, considering the Poisson probabilistic model and the hypothesis that municipalities with lower immunization coverage or high dropout rates would form space-time clusters. Results: From 2014 to 2021, 38.3% and 12.9% of municipalities achieved a coverage ≥ 95.0% in the first and second doses respectively; 53.6% of municipalities had a high dropout rate (20.0% to 49.9%) and 37.2% had a very high dropout rate. The Northeast region had primary clusters for low coverage of the first (2018 to 2021) and second vaccine doses (2020 to 2021) with higher relative risks (RR) compared to other primary clusters. The RR for high dropout rate was elevated in all Brazilian regions (1.57 to 26.23). Conclusions: In some Brazilian regions, the dropout rate has been high since 2014, signaling a risk of measles resurgence. In turn, space-time analysis indicated lower vaccination coverage in 2020, suggesting the influence of the COVID-19 pandemic.

Objetivo: Evaluar la cobertura de vacunación y las tasas de incumplimiento del esquema de vacunación triple viral en las macrorregiones de Brasil. Métodos: En este estudio ecológico, con un enfoque espaciotemporal, se utilizaron datos del Programa Nacional de Inmunización y del Sistema de Información sobre Recién Nacidos Vivos. Se estimó la variación anual de la cobertura de vacunación y la tasa de incumplimiento del esquema de vacunación triple viral en niños de 12 y 15 meses en 5570 municipios brasileños (en el período 2014-2021). El análisis estadístico se realizó en el conjunto de municipios de cada macrorregión brasileña mediante la técnica de barrido espaciotemporal, con un modelo probabilístico de Poisson y con la hipótesis de que los municipios con menor cobertura de vacunación o tasas altas de incumplimiento formarían conglomerados espaciotemporales. Resultados: En el período 2014-2021, el 38,3% y el 12,9% de los municipios alcanzó una cobertura ≥95,0% para la primera y la segunda dosis de la vacuna triple viral, respectivamente; el 53,6% de los municipios tuvo una tasa de incumplimiento alta (del 20,0% al 49,9%) y el 37,2% una tasa extremadamente alta. En la zona del nordeste se observaron los conglomerados primarios de cobertura baja de la primera y la segunda dosis de la vacuna triple viral (administradas en los períodos 2018-2021 y 2020-2021, respectivamente) con un mayor riesgo relativo (RR), en comparación con los demás conglomerados primarios. Se observó un RR alto de tener una tasa elevada de incumplimiento en todas las macrorregiones de Brasil (de entre 1,57 y 26,23). Conclusiones: En algunas macrorregiones, la tasa de incumplimiento había sido elevada desde el 2014, lo cual indica un riesgo de resurgimiento del sarampión. A su vez, en el análisis espaciotemporal se observó una menor cobertura de vacunación en el 2020, lo que denota la influencia de la pandemia de COVID-19.

Seroprevalence of Diphtheria and Tetanus Immunoglobulin G among the General Health Population in Guangzhou, China.

A seroepidemiological study was conducted in 2018 to assess diphtheria and tetanus antibodies in Guangzhou, China. Diphtheria and tetanus antibody concentrations were measured with an enzyme-linked immunosorbent assay. A total of 715 subjects were enrolled in the study. The overall diphtheria and tetanus toxoid IgG-specific antibody levels were 0.126 IU/mL (95% CI: 0.115, 0.137) and 0.210 IU/mL (95% CI: 0.185, 0.240), respectively; the overall positivity rate was 61.82% (95% CI: 58.14, 65.39) and 71.61% (95% CI: 68.3, 74.92), respectively. The diphtheria and tetanus antibody concentration was decreased by age and increased by doses. The geometric mean concentrations and positivity rate of diphtheria and tetanus antibodies were lowest and below the essential protection level in people over 14 years of age. Compared to children and adolescents, middle-aged people and the aged are at much higher risk of infection with Corynebacterium diphtheriae and Clostridium tetani. The current diphtheria and tetanus immunization schedule does not provide persistent protection after childhood. There is an urgent need to adjust the current immunization schedule.

[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.

Exploratory Study of the Phase IV Immunization Schedule of Quadrivalent Influenza Split-Virion Vaccine in Children Aged 3-8 Years.

This study explored the optimum immunization schedule for the quadrivalent influenza split-virion vaccine containing influenza A strains (H1N1 and H3N2) and B lineage strains (Yamagata and Victoria) in children aged 3-8 years. The 652 participants enrolled were divided into two groups based on a history of influenza immunization (IH group) or no history of influenza immunization (NH group). The groups were administered a two-dose immunization schedule on days 0 and 30. In the NH group, on day 30 after the first dose, the positive rates of influenza hemagglutination-inhibition antibodies of strains H1N1, H3N2, BV, and BY were 85.85%, 71.70%, 65.27% and 60.45%, respectively. The positive rates of BV and BY failed to meet the absolute criteria for evaluating the immunogenicity of influenza vaccine in the population aged 3-60 years (for each strain antibody). On day 30 after the second dose, HI antibodies to strains H1N1, H3N2, BV, and BY met the immunogenicity acceptable criteria. In the IH group, on day 30 after the first dose, HI antibodies to strains H1N1, H3N2, BV, and BY met the acceptable criteria for immunogenicity. The incidence rates of adverse reactions (vaccine-related adverse events) from the first dose up until 30 days after the second dose were 20.80% in the IH group and 19.50% in the NH group. Only two Grade 3 adverse reactions (fever: temperature ≥ 39.5 °C, swelling: area ≥ 50% of the injection site area) occurred in the IH group, and no Grade 3 adverse reactions occurred in the NH group. No serious adverse reactions occurred in either group. We conclude that for the NH group, two doses of quadrivalent influenza vaccine should be administered, and for the IH group, a one-dose regimen is acceptable.

Potential serotype-specific effectiveness against IPD of pneumococcal conjugate vaccines V114 and PCV20 in children given a 2+1 dosing regimen.

BACKGROUND: Next generation, higher valency pneumococcal conjugate vaccines (PCVs) are assessed and licensed by comparing the immune response across serotypes shared with the PCVs that are standard of care for prevention of pneumococcal disease. METHODS: Using a previously qualified method we predicted the serotype-specific vaccine effectiveness (VE) against invasive pneumococcal disease of V114 and PCV20 for the serotypes shared with PCV13 in an EU, Russian, and Australian pediatric population that is recommended to receive a 2 + 1 dosing regimen. RESULTS: The estimated protective antibody concentrations ranged from 0.03 (serotype 23F) to 1.49 µg/mL (serotype 19F). Predicted VE values for V114 ranged from 79% (serotype 5) to 100% (serotype 23F). V114 had comparable effectiveness to PCV13 for all but one of shared serotypes, with predicted higher effectiveness (in V114) against serotype 3 (93% vs. 65%). Predicted VE values for PCV20 ranged from 47% (serotype 3) to 91% (serotype 14). PCV20 predicted VE was lower than PCV13's for serotypes 4, 19F, 23F, 1, 3, 5, 6A, 7F, and 19A. CONCLUSIONS: Predicted serotype-specific VE values suggest that, with a 2 + 1 dosing regimen, V114 will have greater effectiveness than PCV20 against PCV13 serotypes, particularly for the still-prevalent serotype 3. Real-world VE studies will ultimately provide clarity on the effectiveness of novel PCVs and support further confidence in and/or improvements to modeling efforts.

Pediatric pneumococcal conjugate vaccines (PCVs) were first introduced in Europe in the early 2000s and their incorporation into national immunization programs has helped decrease the incidence of invasive pneumococcal disease (IPD) in Europe and globally. However, some IPD persists, due both to the emergence of non-vaccine pneumococcal serotypes and to the persistence of certain vaccine-targeted serotypes. Higher valency vaccines have been developed to help prevent IPD arising from these serotypes. The goal of the present study is to employ a previously developed model to predict the serotype-specific vaccine effectiveness of higher valency PCVs in a pediatric population that is recommended to receive a 2 + 1 dosing schedule.

Equity in vaccine coverage in Uganda from 2000 to 2016: revealing the multifaceted nature of inequity.

BACKGROUND: This study analyses vaccine coverage and equity among children under five years of age in Uganda based on the 2016 Uganda Demographic and Health Survey (UDHS) dataset. Understanding equity in vaccine access and the determinants is crucial for the redress of emerging as well as persistent inequities. METHODS: Applied to the UDHS for 2000, 2006, 2011, and 2016, the Vaccine Economics Research for Sustainability and Equity (VERSE) Equity Toolkit provides a multivariate assessment of immunization coverage and equity by (1) ranking the sample population with a composite direct unfairness index, (2) generating quantitative measure of efficiency (coverage) and equity, and (3) decomposing inequity into its contributing factors. The direct unfairness ranking variable is the predicted vaccination coverage from a logistic model based upon fair and unfair sources of variation in vaccination coverage. Our fair source of variation is defined as the child's age - children too young to receive routine immunization are not expected to be vaccinated. Unfair sources of variation are the child's region of residence, and whether they live in an urban or rural area, the mother's education level, the household's socioeconomic status, the child's sex, and their insurance coverage status. For each unfair source of variation, we identify a "more privileged" situation. RESULTS: The coverage and equity of the Diphtheria-Pertussis-Tetanus vaccine, 3rd dose (DPT3) and the Measles-Containing Vaccine, 1st dose (MCV1) - two vaccines indicative of the health system's performance - improved significantly since 2000, from 49.7% to 76.8% and 67.8% to 82.7%, respectively, and there are fewer zero-dose children: from 8.4% to 2.2%. Improvements in retaining children in the program so that they complete the immunization schedule are more modest (from 38.1% to 40.8%). Progress in coverage was pro-poor, with concentration indices (wealth only) moving from 0.127 (DPT3) and 0.123 (MCV1) in 2000 to -0.042 and -0.029 in 2016. Gains in overall equity (composite) were more modest, albeit significant for most vaccines except for MCV1: concentration indices of 0.150 (DPT3) and 0.087 (MCV1) in 2000 and 0.054 and 0.055 in 2016. The influence of the region and settings (urban/rural) of residence significantly decreased since 2000. CONCLUSION: The past two decades have seen significant improvements in vaccine coverage and equity, thanks to the efforts to strengthen routine immunization and ongoing supplemental immunization activities such as the Family Health Days. While maintaining the regular provision of vaccines to all regions, efforts should be made to alleviate the impact of low maternal education and literacy on vaccination uptake.

Immunogenicity and safety of a live-attenuated varicella vaccine in a healthy population aged 13 years and older: A randomized, double-blind, controlled study.

OBJECTIVES: Vaccines for prevention against varicella are important for adolescents and adults, who have an increased risk of severe varicella. This study aimed to evaluate the immunogenicity and safety of a two-dose immunization schedule of a live-attenuated varicella vaccine (VarV) manufactured by Sinovac (Dalian) in healthy adolescents and adults. METHODS: A randomized, double-blind, controlled clinical trial was conducted in healthy population aged ≥ 13 years old in China. Participants in block 1 were randomly assigned (1:1) to receive two doses of either the test vaccine or an active control vaccine, administered 4, 6 or 8 weeks apart. Participants in block 2 were randomly assigned (2:1) to receive two doses of test vaccine or placebo, administered 10 weeks apart. The primary immunogenicity endpoint was the seroconversion rates and GMTs of varicella zoster virus (VZV) antibodies measured by fluorescent-antibody-to-membrane-antigen (FAMA) 4 weeks post-immunization. The primary safety endpoint was the incidence of adverse reactions within 4 weeks after each dose. RESULTS: A total of 2398 participants were enrolled. The seroconversion rates of VZV antibodies were 79.55 % in the test group and 76.41 % in the active control group respectively 4 weeks after two doses of pooled schedule, with the difference of 3.14 % (95 %CI: -0.69 %, 6.97 %). The GMTs were 1:162.07 and 1:160.04 respectively, with the ratio of 1.013 (95 %CI: 0.910, 1.127). Both the seroconversion rates and GMTs reached the prespecified non-inferiority criteria. Two-dose schedule with an interval of 10 weeks could also induce high immune responses, with a seroconversion rate of 83.22 % and a GMT of 1:160.38 in the test group. Safety profiles were similar among the test group, active control group and placebo group. CONCLUSION: VarV, manufactured by Sinovac (Dalian), demonstrated higher immune response and better flexibility in the immunization schedule among heathy population aged 13 years and older, without increased safety risk.

Impact of hepatitis B birth dose on immune response in Pakistani children: an open-label, non-inferiority randomized controlled trial, implications for achieving SDG target.

BACKGROUND: Despite presence of hyperendemic areas, the national immunisation schedule in Pakistan does not include a hepatitis B birth dose, placing newborns at an additional risk of acquiring hepatitis B. This study aimed to assess the impact of adding hepatitis B birth dose in existing national vaccination schedule. METHODS: An open label, randomised controlled non-inferiority trial enrolled 296 healthy near-term mothers to intervention and control groups. Newborns in the intervention group received a hepatitis B birth dose along with routine immunisation vaccines, while control group newborns received vaccinations under the national schedule. Seroprotection was measured and compared at birth and 8 weeks after administering the third dose of pentavalent vaccine. The risk ratio of seroprotection was computed and compared with the delta value set at 5%. RESULTS: The study found that 95.8% of infants in the intervention group achieved seroprotection, which was significantly higher than the control group's 58.7%. The difference in risk ratio of seroprotection was 1.62 (CI95: 1.37-1.93), with the upper limit of the CI below the delta margin, confirming non-inferiority. The time interval between birth and the first hepatitis B immunisation shot was a predictor of seroprotection, with an odds ratio of 1.79 (CI95: 1.01-2.9). CONCLUSION: Our study indicates that adding a hepatitis B birth dose to the immunisation schedule in Pakistan is non-inferior to the existing one. This can also contribute towards Pakistan's achievement of the SDG target of reducing hepatitis B surface antigen seroprevalence in children under 5 years of age. TRIAL REGISTRATION NUMBER: NCT04870021.

Heterogeneidade espaço-temporal dos indicadores de imunização da vacina tríplice viral em crianças no Brasil / Space-time heterogeneity of measles, mumps, and rubella vaccination indicators in children from Brazil / Heterogeneidad espaciotemporal de los indicadores de inmunización con la vacuna triple viral en la población infantil de Brasil

RESUMO Objetivo. Avaliar a cobertura vacinal e as taxas de abandono da vacina tríplice viral nas macrorregiões brasileiras. Métodos. Este estudo ecológico, com abordagem espaço-temporal, utilizou dados do Programa Nacional de Imunizações e do Sistema de Informação sobre Nascidos Vivos. Estimou-se a variação anual (2014 a 2021) da cobertura vacinal e da taxa de abandono da vacina tríplice viral em crianças de 12 meses e 15 meses de idade nos 5 570 municípios brasileiros. A análise estatística foi realizada para o conjunto de municípios de cada macrorregião brasileira usando a técnica de varredura espaço-temporal, considerando o modelo probabilístico de Poisson e a hipótese de que os municípios com menores coberturas vacinais ou altas taxa de abandono formariam aglomerados (clusters) espaço-temporais. Resultados. De 2014 a 2021, 38,3% e 12,9% dos municípios alcançaram cobertura da vacina tríplice viral ≥ 95,0% na primeira e segunda doses, respectivamente; 53,6% dos municípios tiveram alta taxa de abandono (20,0% a 49,9%) e 37,2% tiveram altíssima taxa de abandono. O Nordeste apresentou os clusters primários para baixa cobertura da primeira (2018 a 2021) e da segunda doses (2020 a 2021) da vacina tríplice viral com maiores riscos relativos (RR) em relação aos demais clusters primários. O RR para alta taxa de abandono foi elevado em todas as macrorregiões brasileiras (1,57 a 26,23). Conclusões. Em algumas macrorregiões, a taxa de abandono era alta desde 2014, sinalizando risco de ressurgimento do sarampo. Por sua vez, a análise espaço-temporal indicou mais baixas coberturas vacinais em 2020, sugerindo influência da pandemia de covid-19.

ABSTRACT Objective. To evaluate immunization coverage and dropout rates of the measles, mumps, and rubella vaccine across Brazilian regions. Methods. This ecological study employing a space-time approach used data from the National Immunization Program (PNI) and the Live Births Information System (SINASC). We estimated the annual variation (2014 to 2021) in immunization coverage and dropout rate of the measles, mumps, and rubella vaccine in children aged 12 and 15 months in the 5 570 Brazilian municipalities. Statistical analysis was conducted for the municipalities contained in each Brazilian region using the space-time scan technique, considering the Poisson probabilistic model and the hypothesis that municipalities with lower immunization coverage or high dropout rates would form space-time clusters. Results. From 2014 to 2021, 38.3% and 12.9% of municipalities achieved a coverage ≥ 95.0% in the first and second doses respectively; 53.6% of municipalities had a high dropout rate (20.0% to 49.9%) and 37.2% had a very high dropout rate. The Northeast region had primary clusters for low coverage of the first (2018 to 2021) and second vaccine doses (2020 to 2021) with higher relative risks (RR) compared to other primary clusters. The RR for high dropout rate was elevated in all Brazilian regions (1.57 to 26.23). Conclusions. In some Brazilian regions, the dropout rate has been high since 2014, signaling a risk of measles resurgence. In turn, space-time analysis indicated lower vaccination coverage in 2020, suggesting the influence of the COVID-19 pandemic.

RESUMEN Objetivo. Evaluar la cobertura de vacunación y las tasas de incumplimiento del esquema de vacunación triple viral en las macrorregiones de Brasil. Métodos. En este estudio ecológico, con un enfoque espaciotemporal, se utilizaron datos del Programa Nacional de Inmunización y del Sistema de Información sobre Recién Nacidos Vivos. Se estimó la variación anual de la cobertura de vacunación y la tasa de incumplimiento del esquema de vacunación triple viral en niños de 12 y 15 meses en 5570 municipios brasileños (en el período 2014-2021). El análisis estadístico se realizó en el conjunto de municipios de cada macrorregión brasileña mediante la técnica de barrido espaciotemporal, con un modelo probabilístico de Poisson y con la hipótesis de que los municipios con menor cobertura de vacunación o tasas altas de incumplimiento formarían conglomerados espaciotemporales. Resultados. En el período 2014-2021, el 38,3% y el 12,9% de los municipios alcanzó una cobertura ≥95,0% para la primera y la segunda dosis de la vacuna triple viral, respectivamente; el 53,6% de los municipios tuvo una tasa de incumplimiento alta (del 20,0% al 49,9%) y el 37,2% una tasa extremadamente alta. En la zona del nordeste se observaron los conglomerados primarios de cobertura baja de la primera y la segunda dosis de la vacuna triple viral (administradas en los períodos 2018-2021 y 2020-2021, respectivamente) con un mayor riesgo relativo (RR), en comparación con los demás conglomerados primarios. Se observó un RR alto de tener una tasa elevada de incumplimiento en todas las macrorregiones de Brasil (de entre 1,57 y 26,23). Conclusiones. En algunas macrorregiones, la tasa de incumplimiento había sido elevada desde el 2014, lo cual indica un riesgo de resurgimiento del sarampión. A su vez, en el análisis espaciotemporal se observó una menor cobertura de vacunación en el 2020, lo que denota la influencia de la pandemia de COVID-19.

Strategies for expanding childhood vaccination in the Americas following the COVID-19 pandemic / Estrategias para ampliar la vacunación infantil en la Región de las Américas después de la pandemia de COVID-19 / Estratégias para ampliar a vacinação infantil nas Américas depois da pandemia de COVID-19

ABSTRACT 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.

RESUMEN Objetivo. Presentar un panorama general de la situación del calendario de vacunación infantil en la Región de las Américas, describir la estructura de los programas y encontrar estrategias actualizadas para su ejecución a fin de mejorar la cobertura de vacunación después de la pandemia de COVID-19. Métodos. Un grupo de expertos en pediatría, epidemiología, vacunas y salud pública y mundial analizó la situación actual del calendario de vacunación infantil en la Región de las Américas, mediante la descripción de la estructura de los programas y la búsqueda de nuevas estrategias de ejecución capaces de mejorar la cobertura de vacunación en el contexto posterior a la pandemia de COVID-19, una vez superados los desafíos planteados por esta durante más de dos años. Resultados. En este momento, en la Región de las Américas hay un riesgo alto de reaparición de enfermedades previamente controladas o eliminadas. En consecuencia, es importante contar con nuevas estrategias para la educación de salud de la ciudadanía sobre los riesgos asociados a las tasas bajas de vacunación, especialmente en la población infantil. Conclusiones. Es necesario contar con nuevas estrategias, acompañadas de una fuerte movilización de la población y una promoción por parte de la ciudadanía, para evitar que los grupos que generan mensajes antivacunas aumenten su presencia en la Región y pongan en peligro la credibilidad del Programa Ampliado de Inmunización.

RESUMO Objetivo. Apresentar um panorama da situação do calendário de vacinação infantil nas Américas, definir a estrutura do programa e identificar estratégias de implementação atualizadas para melhorar a cobertura vacinal depois da pandemia de COVID-19. Métodos. Um grupo de especialistas em pediatria, epidemiologia, vacinas e saúde pública e global discutiu a situação atual do calendário de vacinação infantil nas Américas, descrevendo a estrutura dos programas e identificando novas estratégias de implementação que poderiam melhorar a cobertura vacinal no contexto pós-pandemia, na sequência dos desafios impostos pela COVID-19 durante mais de dois anos. Resultados. Atualmente, as Américas enfrentam um grande risco de ressurgimento de doenças já controladas ou eliminadas. Desse modo, é importante identificar novas estratégias para conscientizar os cidadãos sobre os riscos decorrentes da queda das taxas de vacinação, sobretudo em crianças. Conclusões. É necessário adotar novas estratégias, aliadas a uma forte mobilização da população e promoção da causa pelos cidadãos, a fim de impedir que os grupos antivacinas fortaleçam sua presença na região e coloquem em risco a credibilidade do Programa Ampliado de Imunização.

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

RESUMEN Objetivo. Construir y comparar el ranking de los programas nacionales de inmunizaciones (PNI) de América Latina del año 2020 con el año anterior. Métodos. Se evaluaron 18 PNI con base en la información pública obtenida de sitios oficiales de los ministerios de salud de los países, la Organización Mundial de la Salud, la Organización Panamericana de la Salud, el Fondo de las Naciones Unidas para la Infancia y referentes locales. El ranking se elaboró con base en el calendario de vacunación del año 2020 en distintas etapas de la vida, situaciones especiales, vacunación antigripal, coberturas vacunales (CV) del 2019 y aspectos programáticos. Resultados. Las CV disminuyeron en la mayoría de los países. El puntaje promedio regional y de la mayoría de los países también bajó en el 2020 excepto en Chile y Colombia. Chile lidera el ranking, seguido por Uruguay, Panamá y Costa Rica, y se destaca por su calendario completo, mayores CV y logros programáticos. Conclusiones. El menor puntaje global del 2020 resalta que es necesario recuperar la CV en la Región. Este análisis busca motivar a los países a abordar los desafíos pendientes.

ABSTRACT 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.

RESUMO 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.

Summary of the NACI Statement on Public Health Level Recommendations on the Use of Pneumococcal Vaccines in Adults, Including the Use of 15-valent and 20-valent Conjugate Vaccines.

Background: Age and certain medical/social conditions are risk factors for invasive pneumococcal disease (IPD). For prevention of IPD, the National Advisory Committee on Immunization (NACI) has recommended the 23-valent polysaccharide pneumococcal vaccine, PNEU-P-23, for adults 65 years of age and older and adults over 18 years of age living with certain underlying conditions. NACI has also recommended 13-valent conjugate pneumococcal vaccine, PNEU-C-13, for adults; however, in publicly funded programs, this recommendation is limited to individuals with risk factors for IPD. Two new conjugate vaccines, PNEU-C-15 and PNEU-C-20, have been authorized by Health Canada for prevention of IPD in adults. This article summarizes NACI public health recommendations for pneumococcal vaccines in adults given these new conjugate vaccines that provide additional serotype coverage over PNEU-C-13. Methods: Key studies evaluating the immunogenicity and safety of PNEU-C-15 and PNEU-C-20 were reviewed. The Grading of Recommendations, Assessment, Development and Evaluations framework methodology was used to assess the certainty of evidence. Results: The PNEU-C-15 and PNEU-C-20 vaccines showed comparable immune responses, and safety profiles for all mild, moderate, and severe adverse events, to the currently used vaccines. No data were available on the efficacy or effectiveness of PNEU-C-15 or PNEU-C-20. Economic evidence and feasibility assessments supported the use of the PNEU-C-20 vaccine. Conclusion: NACI recommends PNEU-C-20 for adults 65 years of age and older, 50-64 years of age and living with factors placing them at higher risk of pneumococcal disease, and 18-49 years of age with immunocompromising conditions, with PNEU-C-15+PNEU-P-23 an alternative.

Impact of an Intervention to Promote the Vaccination of Patients with Inflammatory Bowel Disease.

Patients with inflammatory bowel disease (IBD) have a dysregulated immune system, being at high risk of opportunistic infections. Low vaccination rates hinder the prevention of such diseases. Therefore, we implemented an intervention to increase vaccination rates, and we aimed to evaluate the effect. We determined the change in professionals and the change in the vaccination rates after the intervention. A quasi-experimental study was carried out using data from 31 December 2016 to 31 December 2021. First, healthcare professionals specializing in IBD agreed on a vaccination protocol; then, this protocol was passed on to the professionals involved in vaccination. We evaluated the perception of knowledge, capacity, and intention to vaccinate patients with IBD among the professionals before and after the intervention with a survey. We also described the effectiveness of the intervention for already diagnosed patients and compared the vaccination rates between patients diagnosed prior to the intervention and newly diagnosed patients. The intervention resulted in an improved perception of knowledge, capacity, and intention to vaccinate patients with IBD among the professionals (p < 0.05). Moreover, during the post-intervention period, in the 315 patients, the vaccination rate increased for all immune-preventable diseases (p < 0.05). The professionals positively valued the intervention, and compliance with the recommended vaccination protocol in patients with IBD improved significantly.

Predictors for Uptake of Vaccines Offered during the Second Year of Life: Second Dose of Measles-Containing Vaccine and Meningococcal Serogroup A-Containing Vaccine, Ghana, 2020.

BACKGROUND: Understanding the drivers of coverage for vaccines offered in the second year of life (2YL) is a critical focus area for Ghana's life course approach to vaccination. This study characterizes the predictors of vaccine receipt for 2YL vaccines-meningococcal serogroup A conjugate vaccine (MACV) and the second dose of measles-containing vaccine (MCV2)-in Ghana. METHODS: 1522 children aged 18-35 months were randomly sampled through household surveys in the Greater Accra Region (GAR), Northern Region (NR), and Volta Region (VR). The association between predictors and vaccination status was modeled using logistic regression with backwards elimination procedures. Predictors included child, caregiver, and household characteristics. RESULTS: Coverage was high for infant vaccines (>85%) but lower for 2YL vaccines (ranging from 60.2% for MACV in GAR to 82.8% for MCV2 in VR). Predictors of vaccination status varied by region. Generally, older, first-born children, those living in rural settlements and those who received their recommended infant vaccines by their first birthday were the most likely to have received 2YL vaccines. Uptake was higher among those with older mothers and children whose caregivers were aware of the vaccination schedule. CONCLUSIONS: Improving infant immunization uptake through increased community awareness and targeted strategies, such as parental reminders about vaccination visits, may improve 2YL vaccination coverage.

Comparación de protocolos de vacunación contra el virus del papiloma humano en Ecuador y América Latina / Comparation of vaccination protocols against the human papillomavirus in Ecuador and Latin America

INTRODUCCIÓN: El virus del papiloma humano (VPH), con más de 100 tipos, es de transmisión sexual. Varios países de América Latina han introducido las vacunas contra el VPH. Aunque América Latina es la región que más rápido avanzó en la vacunación contra el VPH, sus sistemas de seguimiento y vigilancia son aún deficientes. OBJETIVO: Comparar las diferentes estrategias de vacunación contra el VPH en Ecuador y América Latina. MÉTODO: Revisión bibliográfica, en la que se obtuvo información de documentos gubernamentales y artículos indexados en los últimos 5 años sobre las estrategias de vacunación contra el VPH en Ecuador y América Latina. RESULTADOS: La mayoría de los países de América Latina han logrado introducir la vacuna contra el VPH, excepto Venezuela, Martinica, Haití, Nicaragua y Cuba. CONCLUSIONES: Los protocolos de vacunación de Ecuador y América Latina necesitan mejorar sus sistemas de seguimiento y aumentar la expansión de datos de cobertura disponibles de manera consistente. Actualmente siguen existiendo desafíos para introducir las vacunas, lograr una alta cobertura y fortalecer el seguimiento, la evaluación y la notificación.

INTRODUCTION: The human papilloma virus (HPV), with more than 100 types, is a sexual transmission infection. Many Latin American countries have introduced the vaccines against the HPV. Although Latin América is the region which advanced faster against the HPV, its surveillance and follow-up systems are yet deficient. OBJECTIVE: To compare the different strategies to assume the vaccination against the HPV in Ecuador and Latin America. METHOD: Bibliographic review, in which information was obtained from government documents and articles indexed in the last five years on vaccination strategies against HPV in Ecuador and Latin America. RESULTS: Most Latin American countries have managed to introduce the vaccine against the HPV, except Venezuela, Martinica, Haiti, Nicaragua and Cuba. CONCLUSIONS: The vaccination protocols of Ecuador and Latin América need to improve their systems of follow-up and monitoring, and increase the expansion of available data in a consistent manner. Now, there are still existing challenges to introduce the vaccines, manage a high reach and fortify the follow-up, the evaluation, and the notification.

Evaluating immune responses to pneumococcal vaccines.

Streptococcus pneumoniae (pneumococcus) is a significant cause of bacterial infections ranging from mild infections affecting the respiratory tract such as otitis media and sinusitis to severe diseases including bacteremia, pneumonia, and invasive pneumococcal disease (IPD) (eg, meningitis, septic arthritis, and endocarditis). Pneumococcal vaccines were first developed in the 1970s as capsular pneumococcal polysaccharide vaccines, which were T-cell independent and hence lacked immunologic memory. Subsequently in the year 2000, pneumococcal conjugate vaccines (PCV) conjugated to a protein to increase immunogenicity were developed and made commercially available. The increasing number of pneumococcal serotypes identified and the expanding pipeline of PCV vaccines with improved immunogenicity have significantly reduced the morbidity and mortality associated with IPD in high-risk patients. Pneumococcal vaccines also play an important role in the diagnosis and immunophenotyping of children and adults with inborn errors of immunity (IEI) given the increasing diversity/heterogeneity of IEI presenting with primary and/or specific antibody deficiency. Other than the quantitation of serotype levels in routine clinical care, other measurements of immune response including the functional activity of antibodies, antibody avidity, cell-mediated immunity, and immunological memory remain limited to clinical trials during vaccine development.

Factors Affecting Human Papillomavirus Vaccine Trends in the United States of America.

Background Routine immunization of both girls and boys starting from nine years of age with the human papillomavirus (HPV) vaccine is the current recommendation. The objective of this retrospective study using National Health and Nutrition Examination Survey data was to evaluate the influence of sociodemographic factors on the series initiation and completion of the HPV vaccine from 2011 to 2020. Methodology The chi-square test was used to examine the statistical significance of the association between categorical variables and receipt of the HPV vaccine. The Cochran-Armitage test for trend was employed to assess the statistical significance of temporal trends in risk factors associated with rates of HPV vaccination. These trends were further quantified by a significant rate ratio by comparing them against the most recent survey years. Results HPV vaccine uptake was higher in the 9-14-year age group across survey years and had increased for both males and females over that time. The first dose of the HPV vaccine was most likely to be received by the 11-18-year age group. In the most recent survey of 2017-2020, the highest number of vaccination series completion was achieved for Gardasil®. Conclusions Improved physician efforts and strategies to vaccinate males, low socioeconomic strata patients, and ethnic minorities in more numbers are needed.

Vaccination schedule for adolescents. Consensus of the AEV, CAV-AEP and SEMA.

We present the consensus document on the immunization schedule for adolescents developed by 3 scientific societies: the Spanish Association of Pediatrics (AEP), through its Advisory Committee on Vaccines (CAV-AEP), the Spanish Society of Adolescent Medicine (SEMA) and the Spanish Association of Vaccinology (AEV). There are particularities in infectious disease during adolescence, such as an increased susceptibility to pertussis, poorer outcomes of chickenpox, mumps and hepatitis A, a high incidence of sexually transmitted infections or increased prevalence of meningococcal carriage. The document analyses the schedule for adolescents in the context of vaccination policy overall. It contemplates the vaccines to be included in the immunization schedule for healthy adolescents: against invasive meningococcal disease (tetravalent ACWY and B), against human papillomavirus (which should be gender-neutral), against pertussis, against influenza and against SARS-CoV-2 (in unvaccinated individuals and at-risk groups). It is worth noting that the 4CMenB vaccine appears to confer some protection against gonococcal infection, which would be a considerable added value for adolescents. The vaccination of adolescents belonging to risk groups or travelling abroad also needs to be contemplated, as is the case in any other age group. Vaccination against hepatitis A, which is included in the routine immunization schedule of Catalonia, Ceuta and Melilla from the second year of life, should also be considered a priority in adolescents traveling to endemic areas.

Temporal and spatial distribution trends of polio vaccine coverage in less than one-year old children in Brazil, 2011-2021.

BACKGROUND: Low polio vaccine coverage can result in the spread of Poliovirus to areas free from viral circulation. This study analyzed the temporal trends and spatial distribution of polio vaccine coverage in one year-old children in Brazil, between 2011 and 2021. METHODS: This was an ecological, time-series study (2011 to 2021) with annual vaccine coverages against poliomyelitis, extracted from the Information System of the National Immunization Program from the 26 States and the Distrito Federal (DF). The percentage reductions in vaccination coverage in Brazil and in the Regions were calculated. Prais-Winsten regression models were used to analyze time series for the Regions and States, and spatial analysis identified the distribution of clusters (high-high; low-low; high-low and low-high) of vaccination coverages across Brazilian municipalities, using a 5% significance level. RESULTS: From 2011 to 2021, the coverage of polio vaccines decreased by 29,9%. There was a progressive increase observed in clusters resulting in low vaccination coverages (140 low-low Brazilian municipalities in 2011 vs. 403 in 2021), mostly reported in the North and Northeast regions of the country. There was a downward trend in vaccination coverages in 24 of the 26 States and DF (p ≤ 0.05). CONCLUSIONS: The reduction in polio vaccine coverage, as observed in the North and Northeast regions of Brazil, may favor the spread of Poliovirus. Therefore, vaccination strategies should be prioritized for children residing in areas with sharp and recurrent declines in vaccination coverages, including travelers, migrants, and refugees.