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Objective To quantify the association between reduction in child mortality and routine immunization across 204 countries and territories from 1990 to 2019. Methods We used child mortality and vaccine coverage data from the Global Burden of Disease Study. We used a modified child survival framework and applied a mixed-effects regression model to estimate the reduction in deaths in children younger than 5 years associated with eight vaccines. Findings Between 1990 and 2019, the diphtheria--tetanus--pertussis (DTP), measles, rotavirus and Haemophilus influenzae type b vaccines were significantly associated with an estimated 86.9 (95% confidence interval, CI: 57.2 to 132.4) million fewer deaths in children younger than 5 years worldwide. This decrease represented a 24.2% (95% CI: 19.8 to 28.9) reduction in deaths relative to a scenario without vaccines. The DTP and measles vaccines averted 46.7 (95% CI: 30.0 to 72.7) million and 37.9 (95% CI: 25.4 to 56.8) million deaths, respectively. Of the total reduction in child mortality associated with vaccines, 84.2% (95% CI: 83.0 to 85.1) occurred in 73 countries supported by Gavi, the Vaccine Alliance, with an estimated 45.4 (95% CI: 29.8 to 69.2) million fewer deaths from 2000 to 2019. The largest reductions in deaths associated with these four vaccines were in India, China, Ethiopia, Pakistan and Bangladesh (in order of the size of reduction). Conclusion Vaccines continue to reduce childhood mortality significantly, especially in Gavi-supported countries, emphasizing the need for increased investment in routine immunization programmes. [ABSTRACT FROM AUTHOR]

Objective To assess spatiotemporal trends in, and determinants of, the acceptance of coronavirus disease 2019 (COVID-19) vaccination globally, as expressed on the social media platform X (formerly Twitter). Methods We collected over 13 million posts on the platform regarding COVID-19 vaccination made between November 2020 and March 2022 in 90 languages. Multilingual deep learning XLM-RoBERTa models annotated all posts using an annotation framework after being finetuned on 8125 manually annotated, English-language posts. The annotation results were used to assess spatiotemporal trends in COVID-19 vaccine acceptance and confidence as expressed by platform users in 135 countries and territories. We identified associations between spatiotemporal trends in vaccine acceptance and country-level characteristics and public policies by using univariate and multivariate regression analysis. Findings A greater proportion of platform users in the World Health Organization's South-East Asia, Eastern Mediterranean and Western Pacific Regions expressed vaccine acceptance than users in the rest of the world. Countries in which a greater proportion of platform users expressed vaccine acceptance had higher COVID-19 vaccine coverage rates. Trust in government was also associated with greater vaccine acceptance. Internationally, vaccine acceptance and confidence declined among platform users as: (i) vaccination eligibility was extended to adolescents; (ii) vaccine supplies became sufficient; (iii) nonpharmaceutical interventions were relaxed; and (iv) global reports on adverse events following vaccination appeared. Conclusion Social media listening could provide an effective and expeditious means of informing public health policies during pandemics, and could supplement existing public health surveillance approaches in addressing global health issues. [ABSTRACT FROM AUTHOR]

Problem A decrease in vaccine coverage in conflict-affected areas has placed Yemen at higher risk of polio outbreaks caused by vaccinederived poliovirus strains. Approach In response to polio outbreaks, the Yemeni health ministry and partners initiated multiple vaccination campaigns to deliver vaccines to children. We also implemented several measures to enhance communication, education, health promotion and hygiene, especially in camps for internally displaced people. Local setting In 2009, Yemen achieved polio-free status and maintained it until 2019. However, the ongoing political conflict since 2015, coupled with challenges in delivering the polio vaccine to conflict-affected areas, resulted in two polio outbreaks: 35 cases caused by vaccine-derived poliovirus strain 1 between 2019 and 2021, and 230 cases due to vaccine-derived poliovirus strain 2 between November 2021 and December 2022. Relevant changes In response to the first outbreak, by the end of 2020, we vaccinated 7.2 million children through nationwide vaccination campaigns, except in Sa'ada governorate due to a ban by the authorities. By the end of 2021, 3 800 313 children younger than 5 years had received polio vaccines. For the second outbreak, by the end of 2022, 4 463 389 vaccines had been given to children younger than 10 years, and 1 217 423 to those younger than 5 years. Lessons learnt Vaccination campaigns in conflict-affected areas with low vaccine coverage remain crucial in eradicating polio. Efforts are needed to reach vulnerable groups such as displaced populations. Advocacy, communication and social mobilization actions help ensure broader public inclusion and participation in vaccination efforts to prevent polio outbreaks. [ABSTRACT FROM AUTHOR]

Problem In 2021, Central African Republic was facing multiple challenges in vaccinating its population against coronavirus disease 2019 (COVID-19), including inadequate infrastructure and funding, a shortage of health workers and vaccine hesitancy among the population. Approach To increase COVID-19 vaccination coverage, the health ministry used three main approaches: (i) task shifting to train and equip existing community health workers (CHWs) to deliver COVID-19 vaccination; (ii) evidence gathering to understand people's reluctance to be vaccinated; and (iii) bundling of COVID-19 vaccination with the polio vaccination programme. Local setting Central African Republic is a fragile country with almost two thirds of its population in need of humanitarian assistance. Despite conducting two major COVID-19 vaccination campaigns, by January 2022 only 9% (503 000 people) of the 5 570 659 general population were fully vaccinated. Relevant changes In the 6 months from February to July 2022, Central African Republic tripled its coverage of COVID-19 vaccination to 29% (1 615 492 out of 5 570 659 people) by August 2022. The integrated polio--COVID-19 campaign enabled an additional 136 040 and 218 978 people to be vaccinated in the first and second rounds respectively, at no extra cost. Evidence obtained through surveys and focus group discussions enabled the health ministry to develop communication strategies to dispel vaccine hesitancy and misconceptions. Lessons learnt Task shifting COVID-19 vaccination to CHWs can be an efficient solution for rapid scaling-up of vaccination campaigns. Building trust with the community is also important for addressing complex health issues such as vaccine hesitancy. Collaborative efforts are necessary to provide access to COVID-19 vaccines for high-risk and vulnerable populations. [ABSTRACT FROM AUTHOR]

Objective To study the link between coronavirus disease 2019 (COVID-19) vaccination status and adherence to public health and social measures in Members of the Eastern Mediterranean Region and Algeria. Methods We analysed two rounds of a large, cross-country, repeated cross-sectional mobile phone survey in June--July 2021 and October--November 2021. The rounds included 14 287 and 14 131 respondents, respectively, from 23 countries and territories. Questions covered knowledge, attitudes and practices around COVID-19, and demographic, employment, health and vaccination status. We used logit modelling to analyse the link between self-reported vaccination status and individuals' practice of mask wearing, physical distancing and handwashing. We used propensity score matching as a robustness check. Findings Overall, vaccinated respondents (8766 respondents in round 2) were significantly more likely to adhere to preventive measures than those who were unvaccinated (5297 respondents in round 2). Odds ratios were 1.5 (95% confidence interval, CI: 1.3-1.8) for mask wearing; 1.5 (95% CI: 1.3-1.7) for physical distancing; and 1.2 (95% CI: 1.0-1.4) for handwashing. Similar results were found on analysing subsamples of low- and middle-income countries. However, in high-income countries, where vaccination coverage is high, there was no significant link between vaccination and preventive practices. The association between vaccination status and adherence to public health advice was sustained over time, even though self-reported vaccination coverage tripled over 5 months (19.4% to 62.3%; weighted percentages). Conclusion Individuals vaccinated against COVID-19 maintained their adherence to preventive health measures. Nevertheless, reinforcement of public health messages is important for the public's continued compliance with preventive measures. [ABSTRACT FROM AUTHOR]

Objective. To assess how relevant the flow of people between communities is, compared to vaccination and type of vector, on the spread and potential outbreaks of yellow fever in a disease-free host community. Methods. Using a SEIRV-SEI model for humans and vectors, we applied numerical simulations to the scenarios: (1) migration from an endemic community to a disease-free host community, comparing the performance of Haemagogus janthinomys and Aedes aegypti as vectors; (2) migration through a transit community located on a migratory route, where the disease is endemic, to a disease-free one; and (3) effects of different vaccination rates in the host community, considering the vaccination of migrants upon arrival. Results. Results show no remarkable differences between scenarios 1 and 2. The type of vector and vaccination coverage in the host community are more relevant for the occurrence of outbreaks than migration rates, with H. janthinomys being more effective than A. aegypti. Conclusions. With vaccination being more determinant for a potential outbreak than migration rates, vaccinating migrants on arrival may be one of the most effective measures against yellow fever. Furthermore, H. janthinomys is a more competent vector than A. aegypti at similar densities, but the presence of A. aegypti is a warning to maintain vaccination above recommended levels. [ABSTRACT FROM AUTHOR]

Objective. To describe the variation in COVID-19 mortality among residents of Cali, Colombia, in the second wave of the pandemic, before vaccines, and in the fourth wave, with vaccination roll-out in process, taking into account variables of sex, age group, comorbidities, and interval between onset of symptoms and death, and to estimate the number of deaths averted by vaccination. Methods. A cross-sectional study of second wave and fourth wave deaths and vaccination coverage. The frequencies of attributes of deceased population in the two waves were compared, including comorbidities. Machado's method was used to calculate an estimate of the number of deaths averted in the fourth wave. Results. There were 1 133 deaths in the second wave and 754 deaths in the fourth wave. It was calculated that approximately 3 763 deaths were averted in the fourth wave in Cali in the context of vaccination roll-out. Conclusions. The decline in COVID-19-associated mortality observed supports the continuation of the vaccination program. Given the lack of data to explain other possible reasons for this decline, such as on the severity of novel viral variants, the limitations of the study are discussed. [ABSTRACT FROM AUTHOR]

Objective. To document the evolution of socioeconomic and geographical inequalities in childhood vaccination in Mexico from 2012 to 2021. Methods. Repeated cross-sectional analysis using three rounds of National Health and Nutrition Surveys (2012, 2018, and 2021). Dichotomous variables were created to identify the proportion of children who received no dose of each vaccine included in the national immunization schedule (BCG; diphtheria, pertussis, and tetanus-containing; rotavirus; pneumococcal conjugate; and measles, mumps, and rubella [MMR]), and the proportion completely unvaccinated. The distribution of unvaccinated children was analyzed by state, and by socioeconomic status using the concentration index. Results. The prevalence of completely unvaccinated children in Mexico was low, with 0.3% children in 2012 and 0.8% children in 2021 receiving no vaccines (p = 0.070). Notwithstanding, for each vaccine, an important proportion of children missed receiving any dose. Notably, the prevalence of MMR unvaccinated children was 10.2% (95% CI 9.2--11.1) in 2012, 22.3% (95% CI 20.9--23.8) in 2018, and 29.1% (95% CI 26.3--31.8) in 2021 (p < 0.001 for the difference between 2012 and 2021). The concentration index indicated pro-rich inequalities in non-vaccination for 2 of 5 vaccines in 2012, 3 of 5 vaccines in 2018, and 4 of 5 vaccines in 2021. There were marked subnational variations. The percentage of MMR unvaccinated children ranged from 3.3% to 17.9% in 2012, 5.5% to 36.5% in 2018, and 13.1% to 72.5% in 2021 across the 32 states of Mexico. Conclusions. Equitable access to basic childhood vaccines in Mexico has deteriorated over the past decade. Vigilant equity monitoring coupled with tailored strategies to reach those left out is urgently required. [ABSTRACT FROM AUTHOR]

The objective of this article was to consider the vaccination challenges in Colombia and Peru and the role of pediatric combination vaccines in overcoming these challenges. Barriers to including new vaccines with more antigens remain apparent in parts of these countries, where vaccine-preventable diseases in infants continue to be a major problem. The challenges include the heterogeneity of vaccine coverage within each country and in neighboring countries, which can contribute to poor rates of vaccination coverage; the adverse impact of the inward migration of unvaccinated individuals, which has favored the re-emergence of vaccine-preventable diseases; vaccine shortages; and the impact of the severe acute respiratory syndrome coronavirus 2 (SARSCoV- 2) pandemic and the associated shifts in health care resources. To improve the coverage of pediatric vaccines in Colombia and Peru, it will be necessary to ensure the widespread integration into vaccine schedules of combination vaccines containing diphtheria, tetanus, acellular pertussis, inactivated poliovirus, Haemophilus influenzae type b and hepatitis B antigens with a three-dose primary series delivered at 2, 4 and 6 months of age followed by a booster at 18 months of age. Such vaccines play important roles in preventing diphtheria, tetanus and pertussis; eradicating polio; and providing boosting against H. influenzae type b. [ABSTRACT FROM AUTHOR]

The present article discusses the importance of equity in health care access with a focus on the acquisition and distribution of vaccines -- strategic and essential inputs in the context of COVID-19. It also addresses aspects that increase the risk of transmission, reinfection, and emergence of new variants, such as fake news, pandemic denial, and the anti-vax movement, which perpetuate the epidemic cycle. The importance of planning and designing whole-of-society health policies to manage the pandemic, within a national and global context of joint control is underscored, considering the need to ensure universal and timely access to vaccines and inputs and to the logistics necessary for vaccination. Equity is examined as the global guiding principle in reducing COVID-19 vaccination vulnerability, with an emphasis on the Brazilian setting, where, despite a strong vaccination expertise, a scenario of decreasing investment in science and technology, precarious logistical infrastructure, and corruption endangers access to vaccines. Finally, possible paths that can be explored and transformed into initiatives to be performed by various sectors in society are presented -- for example, the prioritization of regions or vulnerable social groups for vaccine distribution -- to ensure that equity in health care access in terms of COVID-19 vaccine coverage is achieved. [ABSTRACT FROM AUTHOR]

This study aims to assess coronavirus disease 2019 (COVID-19) surveillance methods, health resources, vaccination coverage and income stratification and quantify burdens of disease and death in children and adolescents in the Caribbean. The investigation was a descriptive, cross-sectional study that included 15 Caribbean countries/territories and utilized surveys and secondary data sources. Quarantine and isolation measures were robust and surveillance strategies were similar. Pediatric specialists were available across the region, but few had designated pediatric hospitals or high-dependency units. There were more cases in children on islands with larger populations. Compared to high-income countries/territories, upper and lower middle-income countries/territories had higher disease burdens, fewer doctors and nurses per 1 000 population, lower bed capacities, and lower vaccination coverage. Child and adolescent cases ranged from 0.60% to 16.9%, compared with a global case rate of 20.2% in 2021. By August 2021 there were 33 deaths among children from Haiti, Jamaica, Trinidad and Tobago, and Barbados. The respective case fatality rates for 0--9-year-olds and 10--19-year-olds were 2.80 and 0.70 in Haiti, 0.10 and 0.20 in Jamaica, and 0.00 and 0.14 in Trinidad, compared with 0.17 and 0.1 globally. Overall COVID-19 incidence and mortality in children were consistent with global estimates. Limited resources have been offset by availability of pediatricians across the region, and minimally direct effects on children. Prioritization of admission of specific at-risk groups, training of first responders and vaccination campaigns targeting pregnant women and vulnerable children and adolescents could benefit countries with low vaccine coverage rates and limited resources. [ABSTRACT FROM AUTHOR]

Objective To rapidly increase childhood immunization through a preventive, multi-antigen, vaccination campaign in Mambéré-Kadéï prefecture, Central African Republic, where a conflict from 2012 to 2015 reduced vaccination coverage. Methods The three-round campaign took place between December 2015 and June 2016 using: (i) oral poliomyelitis vaccine (OPV); (ii) combined diphtheria, tetanus and pertussis (DTP) vaccine, Haemophilus influenza type B (Hib) and hepatitis B (DTP-Hib-hepatitis B) vaccine; (iii) pneumococcal conjugate vaccine (PCV); (iv) measles vaccine; and (v) yellow fever vaccine. Administrative data were collected on vaccines administered by age group and vaccination coverage surveys were carried out before and after the campaign. Findings Overall, 294 054 vaccine doses were administered. Vaccination coverage for children aged 6 weeks to 59 months increased to over 85% for the first doses of OPV, DTP-Hib-hepatitis B vaccine and PCV and, in children aged 9 weeks to 59 months, to over 70% for the first measles vaccine dose. In children aged 6 weeks to 23 months, coverage of the second doses of OPV, DTP-Hib-hepatitis B vaccine and PCV was over 58% and coverage of the third doses of OPV and DTP-Hib-hepatitis B vaccine was over 20%. Moreover, 61% (5804/9589) of children aged 12 to 23 months had received two PCV doses and 90% (25933/28764) aged 24 to 59 months had received one dose. Conclusion A preventive, multi-antigen, vaccination campaign was effective in rapidly increasing immunization coverage in a post-conflict setting. To sustain high coverage, routine immunization must be reinforced. [ABSTRACT FROM AUTHOR]