Systematic documentation of the introduction of COVID-19 vaccines in Latin America and the Caribbean.

Objective: To document the process of introducing COVID-19 vaccines in a selection of Latin American and Caribbean countries, including the lessons learned and the strengths and weaknesses, and similarities and differences among programs. Methods: This descriptive study is based on a systematic evaluation of the process of introducing COVID-19 vaccines in Argentina, Belize, Brazil, Costa Rica, Panama and Peru. Data were collected through a questionnaire distributed to key stakeholders. Six informants from each of the included countries participated in this study. The period of the study was from December 2021 through September 2022. Results: The main strengths reported by countries were health workers' commitment to delivering vaccinations, evidence-based decision-making, the development of plans for vaccine introduction, the participation of national immunization technical advisory groups, the availability of economic resources and positive actions from the respective Ministry of Health. The main challenges were the actions of antivaccination groups, problems with electronic immunization registries, a lack of vaccines, delays in the delivery of vaccines and the scarcity of health personnel at the local level. Conclusions: Commitment, the participation of multiple sectors, the availability of resources and preparedness planning were some of the many strengths shown by countries introducing COVID-19 vaccines. Weaknesses included third parties' interests, the lack of information systems and difficulty in accessing vaccines and vaccine services. There is a window of opportunity for countries to maintain the good practices that allowed for the processes' strengths and to assess the identified weaknesses to invigorate immunization programs and prepare for future health crises.

Effectiveness of 13-pneumococcal conjugate vaccine (PCV13) against invasive pneumococcal disease in children in the Dominican Republic.

BACKGROUND: Limited data are available on the effectiveness of 13-valent pneumococcal conjugate vaccine (PCV13) in resource-poor settings and PCV naïve populations. The Dominican Republic introduced PCV13 in September 2013 using a 2 + 1 schedule (2, 4, and 12 months) without a catch-up campaign. We evaluated PCV13 effectiveness against vaccine-type (VT) invasive pneumococcal disease (IPD) among children in the Dominican Republic. METHODS: We conducted a matched case-control study. A case-patient was defined as VT-IPD identified by culture or polymerase chain reaction (PCR) from a normally sterile-site in a hospitalized child who was age-eligible to have received ≥1 PCV13 dose. Four age- and neighborhood-matched controls were enrolled for each case-patient. We collected demographic, vaccination history, and risk factor data. Conditional logistic regression was performed. Vaccine effectiveness was calculated as (1- adjusted matched odds ratio for vaccination) X 100%. RESULTS: We enrolled 39 case-patients and 149 matched-controls. Most case-patients had pneumonia with pleural effusion (64%), followed by meningitis (28%) and septicemia (13%). The most common pneumococcal serotypes identified included 14 (18%), 3 (13%), 19A (10%), and 1 (8%). Fewer case-patients had ≥1 PCV13 dose as compared to controls (61.5% vs. 80.0%; p = 0.006). Adjusting for malnutrition and socioeconomic status, VE of ≥1 PCV13 dose compared to no doses was 67.2% (95% CI: 2.3% to 90.0%). Only 44% of controls were up-to-date for PCV13, suggesting low vaccine coverage in the population. CONCLUSIONS: We found that PCV13 provided individual protection against VT-IPD in this resource-poor setting with a PCV-naïve population, despite low PCV13 coverage. Expanding vaccination coverage might increase PCV13 impact.

Knowing the scope of meningococcal disease in Latin America.

Opportunities for strengthening surveillance of meningococcal disease exist between and within countries in Latin America. In August of 2015, a workshop was convened in the city of São Paulo, Brazil, to address the following objectives: 1) to review meningococcal disease burden and vaccine use in Latin America; 2) to evaluate the effectiveness of current meningococcal surveillance practices in the region; 3) to identify challenges to meningococcal surveillance in the region; and 4) to outline steps for strengthening meningococcal surveillance and disease control in the region. Based on the workshop's discussions, recommendations for strengthening surveillance and controlling meningococcal disease in Latin America focus on improving: a) laboratory capabilities for diagnostic testing; b) communication regarding epidemiologic- and laboratory-based analyses; c) communication during outbreaks; d) monitoring of long-term disease outcomes; e) knowledge of vaccines against serogroup B disease; and f) criteria for defining and controlling meningococcal outbreaks. Overall, improving surveillance will help guide strategies for meningococcal disease prevention and control in Latin America.

Existen distintas oportunidades para reforzar los procedimientos de vigilancia de la enfermedad meningocócica entre los países de América Latina y dentro de ellos. En agosto del 2015, se llevó a cabo un taller en la ciudad de São Paulo (Brasil) en el que se trataron los siguientes puntos: 1) examen de la carga de la enfermedad meningocócica y el uso de la vacuna en América Latina; 2) evaluación de la eficacia de los actuales procedimientos de vigilancia de la enfermedad meningocócica en la región; 3) especificación de los retos para la vigilancia de la enfermedad meningocócica en la región; y 4) definición de los pasos para fortalecer los procedimientos de vigilancia de la enfermedad meningocócica y el control de esta enfermedad en la región. Como resultado del taller se formularon recomendaciones para reforzar los procedimientos de vigilancia y control de la enfermedad meningocócica en América Latina que hacían hincapié en mejorar: a) las capacidades de laboratorio con respecto a las pruebas diagnósticas; b) la comunicación sobre los análisis epidemiológicos y de laboratorio; c) la comunicación durante los brotes; d) el seguimiento de las consecuencias de la enfermedad a largo plazo; e) el conocimiento sobre las vacunas contra la enfermedad causada por el serogrupo B; y f) los criterios para definir y controlar los brotes meningocócicos. En términos generales, la mejora de los procedimientos de vigilancia ayudará a delinear las estrategias para la prevención y el control de la enfermedad meningocócica en América Latina.

Existem oportunidades para o reforço da vigilância da doença meningocócica entre os países e em cada país na América Latina. Em agosto de 2015, foi realizado um seminário na cidade de São Paulo, Brasil, com os seguintes objetivos: 1) avaliar a carga da doença meningocócica e o uso da vacina na América Latina; 2) avaliar a eficácia das atuais práticas de vigilância da doença meningocócica na Região; 3) identificar os desafios para a vigilância meningocócica na Região e 4) definir medidas para reforçar a vigilância da doença meningocócica e o controle da doença na Região. Partindo dos debates realizados durante o seminário, foram feitas as seguintes recomendações para reforçar a vigilância e o controle da doença meningocócica na América Latina, dando-se ênfase a melhorar: a) a infraestrutura laboratorial para exames diagnósticos; b) a comunicação das análises epidemiológicas e laboratoriais; c) a comunicação nos surtos; d) o monitoramento dos desfechos da doença a longo prazo; e) o conhecimento sobre as vacinas contra o meningococo do sorogrupo B e f) os critérios para definir e controlar os surtos de doença meningocócica. Em geral, a melhoria da vigilância contribuirá para orientar as estratégias para prevenção e controle da doença meningocócica na América Latina.

Effectiveness of Pentavalent Rotavirus Vaccine Against a Diverse Range of Circulating Strains in Nicaragua.

BACKGROUND: Because >60 rotavirus strains have been reported worldwide, concerns exist about strain replacement after the introduction of rotavirus vaccines, particularly in developing countries with diverse strains and lower efficacy. METHODS: We used the case-control design in 4 hospitals in Nicaragua to assess strain-specific vaccine effectiveness (VE) of a pentavalent rotavirus vaccine (RotaTeq) against rotavirus diarrhea. Cases were identified through prospective strain surveillance with reverse transcription-polymerase chain reaction for 3 years among children hospitalized for diarrhea, and controls were children negative for rotavirus. RESULTS: We enrolled 1178 case-patients, 1082 (92%) with G and P typing, and 4927 controls. A different strain predominated each year with increasing age of the vaccine-eligible cohort during the study period: G2P[4] in 2008 (97%; mean age, 11.9 months), G1P[8] in 2009 (55%; mean age, 17.0 months), and G3P[8] in 2010 (78%; mean age, 17.3 months). Overall VE was 45% (95% confidence interval, 25%-59%). Regardless of the strain, VE estimates were 12%-79% lower among children aged ≥12 months relative to those 6-11 months of age. The lower VE for G3P[8] was related to the higher mean age of cases (17.3 months) compared with the G2P[4] strains (11.9 months), with a significant trend (R(2)= 0.819;P< .001) of declining effectiveness with increasing mean age of the cases. CONCLUSIONS: Introduction of RotaTeq did not result in sustained emergence of any particular strain in Nicaragua. Variation in strain-specific effectiveness was due to an age-related decline in effectiveness rather than differences in protection against the observed strains.

Reduced rotavirus vaccine effectiveness among children born during the rotavirus season: a pooled analysis of 5 case-control studies from the Americas.

Using data from rotavirus vaccine effectiveness (VE) studies, we assessed whether rotavirus season modifies rotavirus VE in infants. In the first year of life, adjusted VE was 72% for children born during rotavirus season and 84% for children born in other months (P = .01). Seasonal factors may interfere with vaccine performance.

Intussusception risk and health benefits of rotavirus vaccination in Mexico and Brazil.

BACKGROUND: Because postlicensure surveillance determined that a previous rotavirus vaccine, RotaShield, caused intussusception in 1 of every 10,000 recipients, we assessed the association of the new monovalent rotavirus vaccine (RV1) with intussusception after routine immunization of infants in Mexico and Brazil. METHODS: We used case-series and case-control methods to assess the association between RV1 and intussusception. Infants with intussusception were identified through active surveillance at 69 hospitals (16 in Mexico and 53 in Brazil), and age-matched infants from the same neighborhood were enrolled as controls. Vaccination dates were verified by a review of vaccination cards or clinic records. RESULTS: We enrolled 615 case patients (285 in Mexico and 330 in Brazil) and 2050 controls. An increased risk of intussusception 1 to 7 days after the first dose of RV1 was identified among infants in Mexico with the use of both the case-series method (incidence ratio, 5.3; 95% confidence interval [CI], 3.0 to 9.3) and the case-control method (odds ratio, 5.8; 95% CI, 2.6 to 13.0). No significant risk was found after the first dose among infants in Brazil, but an increased risk, albeit smaller than that seen after the first dose in Mexico--an increase by a factor of 1.9 to 2.6 - was seen 1 to 7 days after the second dose. A combined annual excess of 96 cases of intussusception in Mexico (approximately 1 per 51,000 infants) and in Brazil (approximately 1 per 68,000 infants) and of 5 deaths due to intussusception was attributable to RV1. However, RV1 prevented approximately 80,000 hospitalizations and 1300 deaths from diarrhea each year in these two countries. CONCLUSIONS: RV1 was associated with a short-term risk of intussusception in approximately 1 of every 51,000 to 68,000 vaccinated infants. The absolute number of deaths and hospitalizations averted because of vaccination far exceeded the number of intussusception cases that may have been associated with vaccination. (Funded in part by the GAVI Alliance and the U.S. Department of Health and Human Services.).

Reductions in Childhood Pneumonia Mortality After Vaccination in the United States.

BACKGROUND: We aim to estimate the magnitude of the reduction in pneumococcal pneumonia and meningitis mortality after the mass introduction of pneumococcal conjugate vaccine (PCV)7 and PCV13 in children in the United States. METHODS: We assessed the trends in mortality rates from pneumococcal pneumonia and meningitis, in the United States between 1994 and 2017. We fitted an interrupted time-series negative binomial regression model (adjusted by trend, seasonality, PCV7/PCV13 coverage, and H. influenzae type b vaccine coverage) to estimate the counterfactual rates without vaccination. We reported a percent reduction in mortality estimates relative to the projected no-vaccination scenario, using the formula 1 minus the incidence risk ratio, with 95% confidence intervals (CIs). RESULTS: Between 1994 and 1999 (the prevaccination period), the all-cause pneumonia mortality rate for 0-1-month-old children was 2.55 per 100,00 pop., whereas for 2-11 months-old children, this rate was 0.82 deaths per 100,000 pop. During the PCV7-period in 0-59-month-old children in the United States, the adjusted reduction of all-cause pneumonia was 13% (95% CI: 4-21) and 19% (95% CI: 0-33) of all-cause meningitis For PCV13, the reductions in this age group were 21% (95% CI: 4-35) for all-cause pneumonia mortality and 22% (95% CI: -19 to 48) for all-cause meningitis mortality. PCV13 had greater reductions of all-cause pneumonia than PCV13 in 6-11-month-old infants. CONCLUSIONS: The universal introduction of PCV7, and later PCV13, for children 0-59 months old in the United States was associated with decreases in mortality due to all-cause pneumonia.

Rotavirus genotypes in children under five years hospitalized with diarrhea in low and middle-income countries: Results from the WHO-coordinated Global Rotavirus Surveillance Network.

Rotavirus is the most common pathogen causing pediatric diarrhea and an important cause of morbidity and mortality in low- and middle-income countries. Previous evidence suggests that the introduction of rotavirus vaccines in national immunization schedules resulted in dramatic declines in disease burden but may also be changing the rotavirus genetic landscape and driving the emergence of new genotypes. We report genotype data of more than 16,000 rotavirus isolates from 40 countries participating in the Global Rotavirus Surveillance Network. Data from a convenience sample of children under five years of age hospitalized with acute watery diarrhea who tested positive for rotavirus were included. Country results were weighted by their estimated rotavirus disease burden to estimate regional genotype distributions. Globally, the most frequent genotypes identified after weighting were G1P[8] (31%), G1P[6] (8%) and G3P[8] (8%). Genotypes varied across WHO Regions and between countries that had and had not introduced rotavirus vaccine. G1P[8] was less frequent among African (36 vs 20%) and European (33 vs 8%) countries that had introduced rotavirus vaccines as compared to countries that had not introduced. Our results describe differences in the distribution of the most common rotavirus genotypes in children with diarrhea in low- and middle-income countries. G1P[8] was less frequent in countries that had introduced the rotavirus vaccine while different strains are emerging or re-emerging in different regions.

Potential intussusception risk versus health benefits from rotavirus vaccination in Latin America.

BACKGROUND: With the recent postlicensure identification of an increased risk of intussusception with rotavirus vaccine, the 14 Latin American countries currently using rotavirus vaccine must now weigh the health benefits versus risks to assess whether to continue vaccination. To inform policy considerations, we estimated excess intussusception cases and mortality potentially caused by rotavirus vaccine for each of the 14 countries and compared these estimates to hospitalizations and deaths expected to be averted through vaccination. METHODS: We used regional rotavirus disease burden and rotavirus vaccine efficacy data, global natural intussusception and regional rotavirus vaccine-related risk estimates, and country-specific diphtheria, tetanus, and pertussus vaccination coverage rates to estimate rotavirus vaccine coverage rates. We performed a probabilistic sensitivity analysis to account for uncertainty in these parameters. RESULTS: For an aggregate hypothetical birth cohort of 9.5 million infants in these 14 countries, rotavirus vaccine would annually prevent 144 746 (90% confidence interval [CI], 128 821-156 707) hospitalizations and 4124 deaths (90% CI, 3740-4239) due to rotavirus in their first 5 years of life but could cause an additional 172 hospitalizations (90% CI, 126-293) and 10 deaths (90% CI, 6-17) due to intussusception, yielding benefit-risk ratios for hospitalization and death of 841:1 (90% CI, 479:1 to 1142:1) and 395:1 (90% CI, 207:1 to 526:1), respectively. In an uncertainty analysis using 10 000 simulations of our probabilistic parameters, in comparing rotavirus disease averted to intussusception events caused, the hospitalization ratio was never below 100:1, and our death ratio fell below 100:1 only once. CONCLUSIONS: The health benefits of vaccination far outweigh the short-term risks and support continued rotavirus vaccination in Latin America.

Decline in diarrhea mortality and admissions after routine childhood rotavirus immunization in Brazil: a time-series analysis.

BACKGROUND: In 2006, Brazil began routine immunization of infants <15 wk of age with a single-strain rotavirus vaccine. We evaluated whether the rotavirus vaccination program was associated with declines in childhood diarrhea deaths and hospital admissions by monitoring disease trends before and after vaccine introduction in all five regions of Brazil with varying disease burden and distinct socioeconomic and health indicators. METHODS AND FINDINGS: National data were analyzed with an interrupted time-series analysis that used diarrhea-related mortality or hospitalization rates as the main outcomes. Monthly mortality and admission rates estimated for the years after rotavirus vaccination (2007-2009) were compared with expected rates calculated from pre-vaccine years (2002-2005), adjusting for secular and seasonal trends. During the three years following rotavirus vaccination in Brazil, rates for diarrhea-related mortality and admissions among children <5 y of age were 22% (95% confidence interval 6%-44%) and 17% (95% confidence interval 5%-27%) lower than expected, respectively. A cumulative total of ~1,500 fewer diarrhea deaths and 130,000 fewer admissions were observed among children <5 y during the three years after rotavirus vaccination. The largest reductions in deaths (22%-28%) and admissions (21%-25%) were among children younger than 2 y, who had the highest rates of vaccination. In contrast, lower reductions in deaths (4%) and admissions (7%) were noted among children two years of age and older, who were not age-eligible for vaccination during the study period. CONCLUSIONS: After the introduction of rotavirus vaccination for infants, significant declines for three full years were observed in under-5-y diarrhea-related mortality and hospital admissions for diarrhea in Brazil. The largest reductions in diarrhea-related mortality and hospital admissions for diarrhea were among children younger than 2 y, who were eligible for vaccination as infants, which suggests that the reduced diarrhea burden in this age group was associated with introduction of the rotavirus vaccine. These real-world data are consistent with evidence obtained from clinical trials and strengthen the evidence base for the introduction of rotavirus vaccination as an effective measure for controlling severe and fatal childhood diarrhea.

Diarrheal Deaths After the Introduction of Rotavirus Vaccination in 4 Countries.

BACKGROUND: We aim in our analysis to estimate the reduction of diarrhea-related mortality rates after introduction of a rotavirus vaccine in subregions of 4 Latin American countries. METHODS: We selected diarrhea-related deaths from individual-level data from death certificates in Brazil, Colombia, Ecuador, and Mexico. Counts were aggregated by region, year and month, and age group for each country. We ran an interrupted time-series analysis using Poisson regression to obtain seasonal and trend-adjusted estimates of impact. Results are reported as percentages (1 - mortality rate ratio). RESULTS: We found a reduction in diarrhea-related mortality in children <5 years old of 18% (95% confidence interval [CI], 15 to 20) for Mexico, 39% (95% CI, 35 to 44) for Colombia, 19 (95% CI, 17 to 22) for Brazil, and -26% (95% CI, -40 to -14) for Ecuador. Using wavelet analyses, we found a reduction of 6- and 12-month seasonality in Brazil, Colombia, and Mexico. We also found that the increased reduction of diarrhea-related deaths was larger with greater prevaccine burden of diarrhea in infants. CONCLUSIONS: Our findings and available evidence support the recommendation from the World Health Organization for the monovalent and/or pentavalent rotavirus vaccine in countries worldwide. We found an increased benefit in those settings with a higher burden of infant diarrhea-related deaths.

Uptake of rotavirus vaccine and national trends of acute gastroenteritis among children in Nicaragua.

BACKGROUND: In October 2006, a new rotavirus vaccine was introduced in Nicaragua and was available free to all age-eligible children. We assessed vaccine uptake and trends in acute gastroenteritis (AGE) to assess vaccine impact. METHODS: We analyzed national data from the period 2001-2007 on the total number of AGE episodes and on RotaTeq vaccine dose administration during 2006-2007. RESULTS: After the introduction of RotaTeq, 1-dose vaccine coverage rates rapidly increased to 80% among age-eligible children. During the 2007 rotavirus season, when combined 2- and 3-dose vaccine coverage among children aged 0-11 months was approximately 26%, the total number of AGE episodes among children aged 0-11 months decreased by 23%, compared with a decrease of 6% among unvaccinated children aged 12-59 months. Furthermore, a 12% decrease in the number of all-cause hospitalizations for AGE was noted among children aged 0-11 months, whereas a approximately 5% increase was observed among children aged 12-59 months. CONCLUSIONS: The high rate of vaccination among age-eligible children soon after vaccine introduction in Nicaragua indicates an efficient immunization program. However, in the age group at risk of rotavirus disease, vaccine coverage during the 2007 rotavirus season had yet to reach a level sufficient for making firm conclusions about vaccine impact. Epidemiologic studies to evaluate vaccine effectiveness and ongoing surveillance as vaccine uptake increases will allow a better assessment of vaccine impact.

Sentinel hospital surveillance for rotavirus in latin american and Caribbean countries.

The burden of rotavirus disease in the Latin American region has been poorly understood despite the promise of effective vaccines. We describe here the implementation and results of a rotavirus surveillance network in the Latin American and Caribbean region. From 2005 through 2007, stool specimens and epidemiologic information were gathered from children <5 years of age who were hospitalized for acute diarrhea (3 looser-than-normal stools within <24 h) lasting <14 days with use of a standardized generic protocol. Stool samples were tested for rotavirus, and a proportion of detected strains were typed. The proportion of samples positive for rotavirus was applied to World Health Organization diarrhea-related mortality estimates to calculate rotavirus-associated mortality. In 2007, the network comprised 54 sites in 11 countries. During 2006-2007, specimens were collected from 19,817 children; 8141 of these specimens were positive for rotavirus. The median percentage of positive specimens in the country was 31.5% (range, 24%-47%). The risk of death from rotavirus diarrhea by age 5 years was 1 of 2874. Strong rotavirus winter seasonality was apparent, even in tropical Central America. Globally common strains (P[8] G1, P[8] G9, and P[4] G2) accounted for >75% of strains, although unusual strains, including G12, were detected at low levels. As rotavirus vaccines continue to be introduced in Latin America, maintenance of surveillance will provide robust pre-introduction data and a platform for estimating vaccine effectiveness and other measures of impact.

Identifying signatures of the impact of rotavirus vaccines on hospitalizations using sentinel surveillance data from Latin American countries.

BACKGROUND: Passive surveillance data are often the only available source of data that can be used to evaluate the population-level impact of vaccination, but such data often suffer from important limitations such as changes in surveillance efforts. This study provides an example of how to identify important signatures of rotavirus vaccine impact, including evaluating the overall effectiveness and changes in rotavirus seasonal dynamics. METHODS: We used data from a standardized sentinel rotavirus surveillance network in six Latin American countries (Bolivia, El Salvador, Guatemala, Honduras, Paraguay, and Venezuela) from 2004 to 2017. A random-effects model was used to evaluate changes in the proportion of rotavirus-associated hospitalizations following vaccine introduction. Harmonic regression models were used to estimate vaccine impact on the number of rotavirus hospitalizations, controlling for trends in rotavirus-negative cases. Changes to rotavirus seasonality were evaluated using center of gravity analysis, wavelet analysis, and harmonic regression. RESULTS: All countries observed declines in the proportion of rotavirus-positive acute diarrhea samples with a mean reduction of 16% (95% confidence interval: 10-22%). We estimate that each 10% increase in vaccine coverage was associated with declines in the number of rotavirus-positive cases, ranging from 4.3% (1.3-7.2%) in Honduras to 21.4% (16.8-25.9%) in Venezuela. The strength of the seasonal peak in rotavirus incidence became smaller after vaccine introduction in Guatemala, Honduras, and Venezuela. Seasonal peaks also shifted later in the surveillance year, especially in higher-mortality countries. CONCLUSIONS: The combination of methods we applied have different strengths that allow us to identify common signatures of rotavirus vaccine impact.

Immunization stress-related responses presenting as psychogenic non-epileptic seizures following HPV vaccination in Rio Branco, Brazil.

IMPORTANCE: The absence of a positive diagnosis of psychogenic non-epileptic seizures (PNES) in immunization stress-related response (ISRR) clusters may have not only a direct impact on affected patients' health but may also reduce compliance to national vaccination programs. It is therefore crucial to develop efficient diagnostic tools and a feasible proposal for proper communication and treatment of ISRR. PURPOSE: To explore the psychogenic nature of patients' convulsive seizures in a suspected outbreak of an ISRR cluster following human papillomavirus vaccination in Rio Branco, Brazil. METHODS: Twelve patients with convulsive seizures were submitted to prolonged intensive video-electroencephalography monitoring, brain magnetic resonance imaging, cerebrospinal fluid diagnostic testing, laboratory subsidiary examinations, and complete neurological and psychiatric evaluations. RESULTS: Ten patients received the positive diagnosis of PNES, and two patients received the diagnosis of idiopathic generalized epilepsy. No biological association was found between the HPV vaccine and the clinical problems presented by the patients. CONCLUSIONS: Prolonged VEEG monitoring can contribute significantly to the positive diagnosis of PNES in ISRR clusters and to avoid hesitancy to vaccinate.

Association between pentavalent rotavirus vaccine and severe rotavirus diarrhea among children in Nicaragua.

CONTEXT: Pentavalent rotavirus vaccine (RV5), a live, oral attenuated vaccine, prevented 98% of severe rotavirus diarrhea in a trial conducted mainly in Finland and the United States. Nicaragua introduced RV5 in 2006, providing the first opportunity to assess the association between vaccination and rotavirus disease in a developing country. OBJECTIVE: To assess the association between RV5 vaccination and subsequent rotavirus diarrhea requiring overnight admission or intravenous hydration. DESIGN, SETTING, AND PARTICIPANTS: Case-control evaluation in 4 hospitals in Nicaragua from June 2007 to June 2008. Cases were children age-eligible to receive RV5 who were admitted or required intravenous hydration for laboratory-confirmed rotavirus diarrhea. For each case (n = 285), 1 to 3 neighborhood (n = 840) and hospital (n = 690) controls were selected. MAIN OUTCOME MEASURES: Primary outcome was the association of RV5 and rotavirus diarrhea requiring overnight admission or intravenous hydration in the emergency department. Secondary analysis further classified disease as severe and very severe. We computed the matched odds ratio of vaccination in cases vs controls. Vaccine effectiveness was estimated using the formula 1 - matched odds ratio x 100%. RESULTS: Of the 285 rotavirus cases, 265 (93%) required hospitalization; 251 (88%) received intravenous hydration. A single rotavirus strain (G2P[4]) was identified in 88% of the cases. Among cases and controls, respectively, 18% and 12% were unvaccinated, 12% and 15% received 1 dose of RV5, 15% and 17% received 2 doses, and 55% and 57% received 3 doses. Vaccination with 3 doses was associated with a lower risk of rotavirus diarrhea requiring overnight admission or intravenous hydration (odds ratio [OR], 0.54; 95% confidence interval [CI], 0.36-0.82). Of the 285 rotavirus cases, 191 (67%) were severe and 54 (19%) were very severe. A progressively lower risk of severe (OR, 0.42; 95% CI, 0.26-0.70) and very severe rotavirus diarrhea (OR, 0.23; 95% CI, 0.08-0.61) was observed after RV5 vaccination. Thus, effectiveness of 3 doses of RV5 against rotavirus disease requiring admission or treatment with intravenous hydration was 46% (95% CI, 18%-64%); against severe rotavirus diarrhea, 58% (95% CI, 30%-74%); and against very severe rotavirus diarrhea, 77% (95% CI, 39%-92%). CONCLUSION: Vaccination with RV5 was associated with a lower risk of severe rotavirus diarrhea in children younger than 2 years in Nicaragua but to a lesser extent than that seen in clinical trials in industrialized countries.

Systematic documentation of the introduction of COVID-19 vaccines in Latin America and the Caribbean / Documentación sistemática de la introducción de vacunas contra la COVID- 19 en América Latina y el Caribe / Documentação sistemática da introdução das vacinas contra a COVID-19 na América Latina e no Caribe

[ABSTRACT]. Objective. To document the process of introducing COVID-19 vaccines in a selection of Latin American and Caribbean countries, including the lessons learned and the strengths and weaknesses, and similarities and differences among programs. Methods. This descriptive study is based on a systematic evaluation of the process of introducing COVID-19 vaccines in Argentina, Belize, Brazil, Costa Rica, Panama and Peru. Data were collected through a questionnaire distributed to key stakeholders. Six informants from each of the included countries participated in this study. The period of the study was from December 2021 through September 2022. Results. The main strengths reported by countries were health workers’ commitment to delivering vaccinations, evidence-based decision-making, the development of plans for vaccine introduction, the participation of national immunization technical advisory groups, the availability of economic resources and positive actions from the respective Ministry of Health. The main challenges were the actions of antivaccination groups, problems with electronic immunization registries, a lack of vaccines, delays in the delivery of vaccines and the scarcity of health personnel at the local level. Conclusions. Commitment, the participation of multiple sectors, the availability of resources and preparedness planning were some of the many strengths shown by countries introducing COVID-19 vaccines. Weaknesses included third parties’ interests, the lack of information systems and difficulty in accessing vaccines and vac- cine services. There is a window of opportunity for countries to maintain the good practices that allowed for the processes’ strengths and to assess the identified weaknesses to invigorate immunization programs and prepare for future health crises.

[RESUMEN]. Objetivo. Documentar el proceso de introducción de las vacunas contra la COVID-19 en un algunos países de América Latina y el Caribe, incluidas las enseñanzas extraídas y sus puntos fuertes y débiles, así como las similitudes y diferencias entre los distintos programas. Métodos. Este estudio descriptivo se basa en una evaluación sistemática del proceso de introducción de las vacunas contra la COVID-19 en Argentina, Belice, Brasil, Costa Rica, Panamá y Perú. Los datos se recopilaron mediante un cuestionario distribuido a las principales partes interesadas. El estudio contó con la participación de un informante de cada uno de los seis países incluidos. El período de estudio fue de diciembre del 2021 a septiembre del 2022. Resultados. Los países indicaron como puntos fuertes principales el compromiso del personal de atención de salud con la vacunación, la toma de decisiones basada en la evidencia, la formulación de planes para la introducción de las vacunas, la participación de grupos técnicos asesores nacionales sobre inmunización, la disponibilidad de recursos económicos y las medidas favorables adoptadas por respectivos los Ministerios de Salud. Los retos más importantes fueron las acciones de los grupos contrarios a las vacunas, los problemas con los registros electrónicos de vacunación, la falta de vacunas, los retrasos en la entrega de vacunas y la escasez de personal de atención de salud a nivel local. Conclusiones. Se observó que el compromiso, la participación de múltiples sectores, la disponibilidad de recursos y la planificación de la preparación eran algunos de los puntos fuertes de los países que introdujeron las vacunas contra la COVID-19. Los puntos débiles fueron los intereses de terceros, la falta de sistemas de información y las dificultades para acceder a las vacunas y a los servicios de vacunación. Los países disponen ahora de una oportunidad para mantener las buenas prácticas que propiciaron los puntos fuertes de los procesos y evaluar los puntos débiles identificados a fin de fortalecer los programas de inmunización y prepararse para futuras crisis de salud.

[RESUMO]. Objetivo. Documentar o processo de introdução da vacina contra a COVID-19 em alguns países da América Latina e do Caribe, incluindo as lições aprendidas e os pontos fortes e fracos, bem como semelhanças e diferenças entre os programas. Métodos. Este estudo descritivo baseia-se em uma avaliação sistemática do processo de introdução das vacinas contra a COVID-19 na Argentina, em Belize, no Brasil, na Costa Rica, no Panamá e no Peru. Os dados foram coletados por meio de um questionário distribuído às principais partes interessadas. Seis informantes de cada um dos países incluídos participaram do estudo, que foi realizado entre dezembro de 2021 e setembro de 2022. Resultados. Os principais pontos fortes relatados pelos países foram o comprometimento dos profissionais de saúde com a vacinação, a tomada de decisões baseadas em evidências, o desenvolvimento de planos para a introdução de vacinas, a participação de grupos técnicos assessores nacionais sobre imunização, a disponibilidade de recursos econômicos e ações positivas dos respectivos ministérios da Saúde. Os principais desafios foram as ações de grupos antivacina, problemas com os registros eletrônicos de imunização, a falta de vacinas, atrasos na entrega das vacinas e a escassez de pessoal de saúde em nível local. Conclusões. O comprometimento, a participação de vários setores, a disponibilidade de recursos e o planejamento de preparação foram alguns dos muitos pontos fortes demonstrados pelos países ao introduzirem as vacinas contra a COVID-19. Entre os pontos fracos estavam os interesses de terceiros, a falta de sistemas de informação e a dificuldade de acesso às vacinas e aos serviços de vacinação. Há uma janela de oportunidade para que os países mantenham as boas práticas que viabilizaram os pontos fortes dos processos e avaliem os pontos fracos identificados a fim de revigorar os programas de imunização e preparar-se para futuras crises sanitárias.

Systematic documentation of the introduction of COVID-19 vaccines in Latin America and the Caribbean / Documentación sistemática de la introducción de vacunas contra la COVID-19 en América Latina y el Caribe / Documentação sistemática da introdução das vacinas contra a COVID-19 na América Latina e no Caribe

ABSTRACT Objective. To document the process of introducing COVID-19 vaccines in a selection of Latin American and Caribbean countries, including the lessons learned and the strengths and weaknesses, and similarities and differences among programs. Methods. This descriptive study is based on a systematic evaluation of the process of introducing COVID-19 vaccines in Argentina, Belize, Brazil, Costa Rica, Panama and Peru. Data were collected through a questionnaire distributed to key stakeholders. Six informants from each of the included countries participated in this study. The period of the study was from December 2021 through September 2022. Results. The main strengths reported by countries were health workers' commitment to delivering vaccinations, evidence-based decision-making, the development of plans for vaccine introduction, the participation of national immunization technical advisory groups, the availability of economic resources and positive actions from the respective Ministry of Health. The main challenges were the actions of antivaccination groups, problems with electronic immunization registries, a lack of vaccines, delays in the delivery of vaccines and the scarcity of health personnel at the local level. Conclusions. Commitment, the participation of multiple sectors, the availability of resources and preparedness planning were some of the many strengths shown by countries introducing COVID-19 vaccines. Weaknesses included third parties' interests, the lack of information systems and difficulty in accessing vaccines and vaccine services. There is a window of opportunity for countries to maintain the good practices that allowed for the processes' strengths and to assess the identified weaknesses to invigorate immunization programs and prepare for future health crises.

RESUMEN Objetivo. Documentar el proceso de introducción de las vacunas contra la COVID-19 en un algunos países de América Latina y el Caribe, incluidas las enseñanzas extraídas y sus puntos fuertes y débiles, así como las similitudes y diferencias entre los distintos programas. Métodos. Este estudio descriptivo se basa en una evaluación sistemática del proceso de introducción de las vacunas contra la COVID-19 en Argentina, Belice, Brasil, Costa Rica, Panamá y Perú. Los datos se recopilaron mediante un cuestionario distribuido a las principales partes interesadas. El estudio contó con la participación de un informante de cada uno de los seis países incluidos. El período de estudio fue de diciembre del 2021 a septiembre del 2022. Resultados. Los países indicaron como puntos fuertes principales el compromiso del personal de atención de salud con la vacunación, la toma de decisiones basada en la evidencia, la formulación de planes para la introducción de las vacunas, la participación de grupos técnicos asesores nacionales sobre inmunización, la disponibilidad de recursos económicos y las medidas favorables adoptadas por respectivos los Ministerios de Salud. Los retos más importantes fueron las acciones de los grupos contrarios a las vacunas, los problemas con los registros electrónicos de vacunación, la falta de vacunas, los retrasos en la entrega de vacunas y la escasez de personal de atención de salud a nivel local. Conclusiones. Se observó que el compromiso, la participación de múltiples sectores, la disponibilidad de recursos y la planificación de la preparación eran algunos de los puntos fuertes de los países que introdujeron las vacunas contra la COVID-19. Los puntos débiles fueron los intereses de terceros, la falta de sistemas de información y las dificultades para acceder a las vacunas y a los servicios de vacunación. Los países disponen ahora de una oportunidad para mantener las buenas prácticas que propiciaron los puntos fuertes de los procesos y evaluar los puntos débiles identificados a fin de fortalecer los programas de inmunización y prepararse para futuras crisis de salud.

RESUMO Objetivo. Documentar o processo de introdução da vacina contra a COVID-19 em alguns países da América Latina e do Caribe, incluindo as lições aprendidas e os pontos fortes e fracos, bem como semelhanças e diferenças entre os programas. Métodos. Este estudo descritivo baseia-se em uma avaliação sistemática do processo de introdução das vacinas contra a COVID-19 na Argentina, em Belize, no Brasil, na Costa Rica, no Panamá e no Peru. Os dados foram coletados por meio de um questionário distribuído às principais partes interessadas. Seis informantes de cada um dos países incluídos participaram do estudo, que foi realizado entre dezembro de 2021 e setembro de 2022. Resultados. Os principais pontos fortes relatados pelos países foram o comprometimento dos profissionais de saúde com a vacinação, a tomada de decisões baseadas em evidências, o desenvolvimento de planos para a introdução de vacinas, a participação de grupos técnicos assessores nacionais sobre imunização, a disponibilidade de recursos econômicos e ações positivas dos respectivos ministérios da Saúde. Os principais desafios foram as ações de grupos antivacina, problemas com os registros eletrônicos de imunização, a falta de vacinas, atrasos na entrega das vacinas e a escassez de pessoal de saúde em nível local. Conclusões. O comprometimento, a participação de vários setores, a disponibilidade de recursos e o planejamento de preparação foram alguns dos muitos pontos fortes demonstrados pelos países ao introduzirem as vacinas contra a COVID-19. Entre os pontos fracos estavam os interesses de terceiros, a falta de sistemas de informação e a dificuldade de acesso às vacinas e aos serviços de vacinação. Há uma janela de oportunidade para que os países mantenham as boas práticas que viabilizaram os pontos fortes dos processos e avaliem os pontos fracos identificados a fim de revigorar os programas de imunização e preparar-se para futuras crises sanitárias.

Global impact of rotavirus vaccine introduction on rotavirus hospitalisations among children under 5 years of age, 2008-16: findings from the Global Rotavirus Surveillance Network.

BACKGROUND: Rotavirus vaccine use in national immunisation programmes has led to declines in hospital admissions for rotavirus gastroenteritis among children; however, the global impact of rotavirus vaccine introduction has not been described using primary data. We describe the impact of rotavirus vaccine introduction on admissions for acute rotavirus gastroenteritis in primarily low-income and middle-income countries, using 9 years of data from the WHO-coordinated Global Rotavirus Surveillance Network (GRSN). METHODS: Between Jan 1, 2008, and Dec 31, 2016, children younger than 5 years of age who were admitted to hospital with acute gastroenteritis were prospectively enrolled in GRSN sites. We included sites that enrolled children and collected stool specimens monthly and tested at least 100 specimens annually in the impact analysis, with a separate analysis taking into account site continuity. We compared proportions of acute gastroenteritis cases positive for rotavirus in the pre-vaccine and post-vaccine periods and calculated mean proportion changes for WHO regions, with 95% CIs; these findings were then compared with interrupted time series analyses. We did further sensitivity analyses to account for rotavirus vaccination coverage levels and sites that collected specimens for at least 11 months per year and tested at least 80 specimens per year. We also analysed the age distribution of rotavirus-positive cases before and after vaccine introduction. FINDINGS: 403 140 children younger than 5 years of age admitted to hospital with acute gastroenteritis from 349 sites in 82 countries were enrolled over the study period, of whom 132 736 (32·9%) were positive for rotavirus. We included 305 789 children from 198 sites in 69 countries in the impact analysis. In countries that had not introduced rotavirus vaccine in their national immunisation programmes, rotavirus was detected in 38·0% (95% CI 4·8-73·4) of admissions for acute gastroenteritis annually whereas in those that have introduced the vaccine, rotavirus was detected in 23·0% (0·7-57·7) of admissions for acute gastroenteritis, showing a 39·6% (35·4-43·8) relative decline following introduction. Interrupted time series analyses confirmed these findings. Reductions by WHO regions ranged from 26·4% (15·0-37·8) in the Eastern Mediterranean Region to 55·2% (43·0-67·4) in the European Region and were sustained in nine countries (contributing up to 31 sites) for 6-10 years. The age distribution of children with rotavirus gastroenteritis shifted towards older children after rotavirus vaccine introduction. INTERPRETATION: A significant and sustained reduction in the proportion of hospital admissions for acute gastroenteritis due to rotavirus was seen among children younger than 5 years in GRSN sites following rotavirus vaccine introduction. These findings highlight the need to incorporate rotavirus vaccines into immunisation programmes in countries that have not yet introduced them and underline the importance of high-quality surveillance. FUNDING: The GRSN receives funding from Gavi, the Vaccine Alliance and the US Centers for Disease Control and Prevention. No specific funding was provided for this Article.

Pneumococcal conjugate vaccine introduction in Latin America and the Caribbean: progress and lessons learned.

In Latin America and the Caribbean, pneumococcus has been estimated to cause 12,000-28,000 deaths, 182,000 hospitalizations, and 1.4 million clinic visits annually. Countries in the Americas have been among the first developing nations to introduce pneumococcal conjugate vaccines into their Expanded Programs on Immunization, with 34 countries and territories having introduced these vaccines as of September 2015. Lessons learned for successful vaccine introduction include the importance of coordination between political and technical decision makers, adjustments to the cold chain prior to vaccine introduction, and the need for detailed plans addressing the financial and technical sustainability of introduction. Though many questions on the Pneumococcal Conjugate Vaccine remain unanswered, the experience of the Americas suggests that the vaccines can be introduced quickly and effectively.