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

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

Interventions addressing routine childhood immunization and its behavioral and social drivers.

Introduction: Despite the advances in vaccination, there are still several challenges in reaching millions of children in low- and middle-income countries (LMICs). In this review, we present an extensive summary of the various strategies used for improving routine immunization in LMICs to aid program implementers in designing vaccination interventions. Methods: Experimental and quasi-experimental impact evaluations conducted in LMICs evaluating the effectiveness of interventions in improving routine immunization of children aged 0-5 years or the intermediate outcomes were included from 3ie's review of systematic reviews. Some additional impact evaluation studies published in recent years in select LMICs with large number of unvaccinated children were also included. Studies were coded to identify interventions and the barriers in the study context using the intervention framework developed in 3ie's Evidence Gap Map and the WHO's Behavioral and Social Drivers (BeSD) of vaccination framework, respectively. Qualitative analysis of the content was conducted to analyze the intervention strategies and the vaccination barriers that they addressed. Results and conclusion: One hundred and forty-two impact evaluations were included to summarize the interventions. To address attitudinal and knowledge related barriers to vaccination and to motivate caregivers, sensitization and educational programs, media campaigns, and monetary or non-monetary incentives to caregivers, that may or may not be conditional upon certain health behaviors, have been used across contexts. To improve knowledge of vaccination, its place, time, and schedule, automated voice messages and written or pictorial messages have been used as standalone or multicomponent strategies. Interventions used to improve service quality included training and education of health workers and providing monetary or non-monetary perks to them or sending reminders to them on different aspects of provision of vaccination services. Interventions like effective planning or outreach activities, follow-up of children, tracking of children that have missed vaccinations, pay-for-performance schemes and health system strengthening have also been used to improve service access and quality. Interventions aimed at mobilizing and collaborating with the community to impact social norms, attitudes, and empower communities to make health decisions have also been widely implemented.

The impact of the COVID-19 pandemic and the free vaccination policy on seasonal influenza vaccination uptake among older adults in Ningbo, Eastern China.

In 2020-21, during the COVID-19 pandemic, a free influenza vaccination program was initiated among the elderly residents in Ningbo, China. The impact of the COVID-19 pandemic and free vaccination policy on influenza vaccine uptake needs to be evaluated. The influenza vaccine uptake among individuals born before 31 December, 1962 from 2017-18 to 2022-23 season in Ningbo was analyzed. Multivariate logistic regressions were used to estimate the impact of the COVID-19 pandemic and free vaccination policy. Our analysis included an average of 1,856,565 individuals each year. Influenza vaccination coverage increased from 1.14% in 2017-18 to 33.41% in 2022-23. The vaccination coverage among the free policy target population was 50.03% in 2022-23. Multivariate analysis showed that free vaccination policy increased influenza vaccine uptake most (OR = 11.99, 95%CI: 11.87-12.11). The initial phase of the pandemic was associated with a positive effect on influenza vaccination (OR = 2.09, 95%CI: 2.07-2.12), but followed by a negative effect in the subsequent two seasons(2021-22: OR = 0.75, 95%CI: 0.73-0.76; 2022-23: OR = 0.40, 95%CI: 0.39-0.40). COVID-19 vaccination in the current season was a positive predictor of influenza vaccine uptake while not completing booster COVID-19 vaccination before was negative predictor in 2022-23. Having influenza vaccine history and having ILI medical history during the last season were also positive predictors of influenza vaccine uptake. Free vaccination policies have enhanced influenza vaccination coverage among elderly population. The COVID-19 pandemic plays different roles in different seasons. Our study highlights the need for how to implement free vaccination policies targeting vulnerable groups with low vaccination coverage.

Establishing a Framework for Evaluating the Effectiveness of Vaccines Targeting National Vaccination Programs.

BACKGROUND: The increasing number of vaccines and the complexity of immunization programs, along with continuous changes in the epidemiology of infectious diseases, necessitate a systematic approach to vaccine effectiveness (VE) evaluation. This study presents a preliminary survey to establish a VE evaluation framework in Korea, focusing on the National Immunization Program. METHODS: Experts' opinions were collected through a two-round online survey targeting key stakeholders. The first round consisted of two multiple-choice questions and two open-ended questions. The second round was a quantitative survey with 17 questionnaires based on five domains derived by analyzing the results of the first-round survey. RESULTS: The results emphasize the necessity and urgency of a government-led VE evaluation system and the establishment of a multidisciplinary evaluation organization. Key considerations include personnel, budget, data integration, legal standards, and surveillance system enhancements. CONCLUSION: These findings provide valuable insights for policymakers, emphasizing the need for collaboration, financial support, and robust data management in developing evidence-based vaccination policies.

The Ethiopian National Immunization Technical Advisory Group (E-NITAG): Establishment, Achievements and the Future.

The National Immunization Program (NIP) was introduced in Ethiopia in 1980. The NIP has expanded the number of vaccines from six to more than 14 in 2023. However, decisions on new vaccine introduction and other vaccine-related matters were not systematically deliberated nationally. Thus, the need to establish a national body to deliberate on vaccine and vaccination matters, in addition to the global immunization advisory groups, has been emphasized in the last decade. This article presents the establishment and achievements of the Ethiopian NITAG. The E-NITAG was established in 2016 and maintained its active role in providing recommendations for new vaccine introduction and improving the delivery of routine vaccines. The external assessment indicated the E-NITAG was highly functional and played a critical role in enhancing the vaccination practice in Ethiopia, especially during the COVID-19 pandemic. The absence of a dedicated secretariat staff was the major bottleneck to expanding the role of the E-NITAG beyond responding to MOH requests. The E-NITAG must be strengthened by establishing a secretariat that can eventually grow as an independent institution to address complex vaccine-related issues the NIP needs to address.

Basic Vaccinations among Children Aged 12-23 Months in Northeast India: Trend, Pattern and Factors Influencing Low Coverage.

India has experienced tremendous progress in childhood immunization through centralized flagship programs since 1985. There is a wide variation of immunization coverage of children aged 12-23 months among Indian states and regions. The North East (NE) region, including eight sister states, has witnessed low immunization coverage (68.4%) with higher dropouts (25%) and nonvaccinations (7.0%). NE Indian states substantially improved childhood immunization from 22.8% in 1992-93 to 68.4% in 2019-2021; still, it is below the national average (77%) and the lowest among the Indian States/UTs. Highly predictive determinants for the outcome of childhood vaccination status include maternal characteristics antenatal care for pregnancy, place of delivery, education level, and media exposure. A large section of the backward hilly tribes is also needed special attention to improving the levels of childhood vaccinations in NE states.

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

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

4CMenB journey to the 10-year anniversary and beyond.

The 4-component meningococcal serogroup B (MenB) vaccine, 4CMenB, the first broadly protective, protein-based MenB vaccine to be licensed, is now registered in more than 50 countries worldwide. Real-world evidence (RWE) from the last decade confirms its effectiveness and impact, with infant immunization programs showing vaccine effectiveness of 71-95% against invasive MenB disease and cross-protection against non-B serogroups, including a 69% decrease in serogroup W cases in 4CMenB-eligible cohorts in England. RWE from different countries also demonstrates the potential for additional moderate protection against gonorrhea in adolescents. The real-world safety profile of 4CMenB is consistent with prelicensure reports. Use of the endogenous complement human serum bactericidal antibody (enc-hSBA) assay against 110 MenB strains may enable assessment of the immunological effectiveness of multicomponent MenB vaccines in clinical trial settings. Equitable access to 4CMenB vaccination is required to better protect all age groups, including older adults, and vulnerable groups through comprehensive immunization policies.

Invasive meningococcal disease, caused by the bacterium Neisseria meningitidis(meningococcus), is rare but often devastating and can be deadly. Effective vaccines are available, including vaccines against meningococcal serogroup B disease. In 2013, the 4-component meningococcal serogroup B vaccine, 4CMenB, became the first broadly protective, protein-based vaccine against serogroup B to be licensed, with the second (bivalent vaccine, MenB-FHbp) licensed the following year. 4CMenB is now registered in more than 50 countries, in the majority, for infants and all age groups. In the US, it is approved for individuals aged 10­25 years. Evidence from immunization programs in the last decade, comparing vaccinated and unvaccinated individuals and the same population before and after vaccination, confirms the effectiveness and positive impact of 4CMenB against serogroup B disease. This also demonstrates that 4CMenB can provide protection against invasive diseases caused by other meningococcal serogroups. Furthermore, N. meningitidis is closely related to the bacterium that causes gonorrhea, N. gonorrhoeae, and emerging real-world evidence suggests that 4CMenB provides additional moderate protection against gonococcal disease. The safety of 4CMenB when given to large numbers of infants, children, adolescents, and adults is consistent with the 4CMenB safety profile reported before licensure.For the future, it would be beneficial to address differences among national guidelines for the recommended administration of 4CMenB, particularly where there is supportive epidemiological evidence but no equitable access to vaccination. New assays for assessing the potential effectiveness of meningococcal serogroup B vaccines in clinical trials are also required because serogroup B strains circulating in the population are extremely diverse across different countries.

The cost of delivering COVID-19 vaccines in Vietnam.

BACKGROUND: The COVID-19 pandemic affected hundreds of millions of people and lives, and vaccination was the safest and most effective strategy to prevent and mitigate the burden of this disease. The implementation of COVID-19 vaccination in Vietnam in 2021 was unprecedentedly challenging in scale and complexity, yet economic evidence on the cost of delivery vaccines thought the program was lacking. METHODS: This retrospective costing study utilized a bottom-up, ingredient-based approach to estimate the cost of delivering COVID-19 vaccines in Vietnam in 2021, from a payer perspective. The study included 38 study sites across all administrative and implementation level, including three geographic areas and two delivery strategies, in two provinces, Hanoi and Dak Lak. The study findings were complemented with qualitative interviews with health staff and stakeholders. RESULTS: The economic cost to deliver one COVID-19 vaccine dose was $1.73, mostly comprised of opportunity costs ($1.14 per dose) which were driven by labor costs ($1.12 per dose). The delivery cost in urban areas was the highest ($2.02), followed by peri-urban areas ($1.45) and remote areas ($1.37). Delivery costs were higher at temporary sites ($1.78) when compared to facility-based delivery ($1.63). Comparing low-volume and high-volume periods showed that the delivery cost decreased significantly as volume increased, from $5.24 per dose to $1.65 per dose. CONCLUSIONS: The study estimates the cost of delivering COVID-19 vaccines in Vietnam in 2021. Enabling factors and challenges during the implementation of the program were explored. Study limitations may lead to underestimation of results and reduce generalizability.

Lessons from a decade of adult vaccine rollout in low- and middle-income countries: a scoping review.

INTRODUCTION: The historical focus of vaccines on child health coupled with the advent of novel vaccines targeting adult populations necessitates exploring strategies for adult vaccine implementation. AREAS COVERED: This scoping review extracts insights from the past decade's experiences introducing adult vaccines in low- and middle-income countries. Among 25 papers reviewed, 19 focused on oral cholera vaccine, 2 on Meningococcal A vaccines, 2 on tetanus toxoid vaccine, 1 on typhoid vaccine, and 1 on Ebola vaccine. Aligned with WHO's Global Framework for New TB Vaccines for Adults and Adolescents, our findings center on vaccine availability, accessibility, and acceptance. EXPERT OPINION: Availability findings underscore the importance of understanding disease burden for prioritization, multi-sectoral collaboration during planning, and strategic resource allocation and coordination. Accessibility results highlight the benefits of leveraging existing health infrastructure and adequately training healthcare workers, and contextually tailoring vaccine delivery approaches to reach challenging sub-groups like working male adults. Central to fostering acceptance, resonant sensitization, and communication campaigns engaging the communities and utilizing trusted local leaders countered rumors and increased awareness and uptake. As we approach the introduction of a new adult TB vaccine, insights from this review equips decision-makers with key evidence-based recommendations to support successful and equitable vaccinations targeting adults.

Surveillance of adverse events following immunisation in Australia annual report, 2021.

Abstract: Annual seasonal influenza epidemics cause substantial disease and economic burden worldwide. During the coronavirus disease 2019 (COVID-19) pandemic in 2020 and 2021, influenza activity significantly declined. However, influenza resurged in Australia following the relaxation of non-pharmaceutical interventions, with increased influenza virus circulation in early 2022 coinciding with the SARS-CoV-2 Omicron BA.2 variant wave. Together with other respiratory virus diseases, these disease impacts on the Australian population and healthcare system have re-emphasised the importance of influenza vaccination and control. We aim to provide an overview of the current seasonal influenza vaccination program in Australia and summarise evidence and considerations underpinning potential future immunisation strategies. Influenza causes disproportionately higher morbidity and mortality in young children and older adults. Other populations at elevated risk from influenza include Aboriginal and Torres Strait Islander peoples, pregnant women, and people with certain underlying medical conditions. All Australians aged ≥ 6 months are recommended to receive influenza vaccine every year. The National Immunisation Program (NIP) provides free vaccine for eligible at-risk populations. While approximately 70% of older adults had received influenza vaccine in 2022, coverage in other age groups remains suboptimal. There are several key unmet needs and challenges, but also potential strategies for enhancing the influenza vaccination program in Australia. Improved monitoring and evaluation, including the use of relevant linked datasets for such purposes, is imperative to better understand variations in coverage and vaccination impact in specific populations. Adoption of evidence-based strategies, such as culturally appropriate resources that consider the characteristics of diverse Australian populations, may also help to achieve higher vaccine coverage rates. Additionally, greater vaccine uptake across the population could be facilitated by expanding the NIP-eligible population where cost-effective, and adopting the use of more effective and different types of vaccines when available.

Determinants of pneumococcal vaccination dropout among children aged 12-23 months in Ethiopia: a secondary analysis from the 2019 mini demographic and health survey.

Background: Vaccination is a cost-effective public health program that helps reduce significant morbidity and mortality in children under the age of five. Worldwide, the number of vaccine-preventable causes of child death has significantly decreased since the Expanded Program of Immunization (EPI) was introduced. However, for a variety of reasons, 23 million children did not have adequate access to vaccines in 2020. Therefore, this study aimed to evaluate the determinants of pneumonia conjugate vaccine (PCV) dropout among children aged 12-23 months in Ethiopia. Methods: The study analyzed cross-sectional data obtained from the 2019 mini Ethiopian demographic and health survey. Multilevel binary logistic regression analysis was utilized, and the best fit model was chosen using the Akaike Information Criteria. The study comprised a weighted sample of 989 children aged 12 to 23 months. The study presented the Adjusted Odds Ratio (AOR) along with a 95% Confidence Interval (CI) to identify the significant factors influencing PCV dropout. Results: The PCV dropout rate was reported at 20.2% in this study. In the multilevel analysis, possession of a health card (AOR = 0.076, 95% CI: 0.019, 0.04), vaccination for PCV 2 (AOR =0.002, 95% CI: 0.023, 0.263), and region 7 (AOR = 6.98, 95% CI: 10.1, 48.31) were significantly associated with children's PCV dropout. Conclusion: Having a health card, having received the PCV 2 vaccinations, and region were significant predictors of PCV dropout. Consequently, health education on immunization for all mothers and region-specific, customized public health interventions are needed to reduce the vaccination dropout rate.

Progress Toward Achieving and Sustaining Maternal and Neonatal Tetanus Elimination - Worldwide, 2000-2022.

Tetanus remains a considerable cause of mortality among undervaccinated mothers and their infants following unhygienic deliveries, especially in low-income countries. Strategies of the maternal and neonatal tetanus elimination (MNTE) initiative, which targets 59 priority countries, include strengthening antenatal immunization of pregnant women with tetanus toxoid-containing vaccines (TTCVs); conducting TTCV supplementary immunization activities among women of reproductive age in high-risk districts; optimizing access to skilled birth attendants to ensure clean deliveries and umbilical cord care practices; and identifying and investigating suspected neonatal tetanus cases. This report updates a previous report and describes progress toward MNTE during 2000-2022. By December 2022, 47 (80%) of 59 priority countries were validated to have achieved MNTE. In 2022, among the 50 countries that reported coverage with ≥2 doses of TTCV among pregnant women, 16 (32%) reported coverage of ≥80%. In 2022, among 47 validated countries, 26 (55%) reported that ≥70% of births were assisted by skilled birth attendants. Reported neonatal tetanus cases worldwide decreased 89%, from 17,935 in 2000 to 1,995 in 2021; estimated neonatal tetanus deaths decreased 84%, from 46,898 to 7,719. However, the global disruption of routine immunization caused by the COVID-19 pandemic impeded MNTE progress. Since 2020, reported neonatal tetanus cases have increased in 18 (31%) priority countries. Integration of MNTE strategies into priority countries' national postpandemic immunization recovery activities is needed to achieve and sustain global elimination.

Comprehensive Review on the Use of Oral Cholera Vaccine (OCV) in Ethiopia: 2019 to 2023.

BACKGROUND: Cholera outbreaks in Ethiopia necessitate frequent mass oral cholera vaccine (OCV) campaigns. Despite this, there is a notable absence of a comprehensive summary of these campaigns. Understanding national OCV vaccination history is essential to design appropriate and effective cholera control strategies. Here, we aimed to retrospectively review all OCV vaccination campaigns conducted across Ethiopia between 2019 and 2023. METHODS: The OCV request records from 2019 to October 2023 and vaccination campaign reports for the period from 2019 to December 2023 were retrospectively accessed from the Ethiopia Public Health Institute (EPHI) database. Descriptive analysis was conducted using the retrospective data collected. RESULTS: From 2019 to October 2023, Ethiopian government requested 32 044 576 OCV doses (31 899 576 doses to global stockpile; 145 000 doses to outside of stockpile). Around 66.3% of requested doses were approved; of which 90.4% were received. Fifteen OCV campaigns (12 reactive and 3 pre-emptive) were conducted, including five two-dose campaigns with varying dose intervals and single-dose campaigns partially in 2019 and entirely in 2021, 2022 and 2023. Overall vaccine administrative coverage was high; except for Tigray region (41.8% in the 1st round; 2nd round didn't occur). The vaccine administrative coverage records were documented, but no OCV coverage survey data was available. CONCLUSIONS: This study represents the first comprehensive review of OCV campaigns in Ethiopia spanning the last five years. Its findings offer valuable insights into informing future cholera control strategies, underscoring the importance of monitoring and evaluation despite resource constraints. Addressing the limitations in coverage survey data availability is crucial for enhancing the efficacy of future campaigns.

Impact of the first year of COVID-19 vaccination strategy in Brazil: an ecological study.

OBJECTIVES: No consensus exists about the best COVID-19 vaccination strategy to be adopted by low-income and middle-income countries. Brazil adopted an age-based calendar strategy to reduce mortality and the burden on the healthcare system. This study evaluates the impact of the vaccination campaign in Brazil on the progression of the reported COVID-19 deaths. METHODS: This ecological study analyses the dynamic of vaccination coverage and COVID-19 deaths in hospitalised adults (≥20 years) during the first year of the COVID-19 vaccination roll-out (January to December 2021) using nationwide data (DATASUS). We stratified the adult population into 20-49, 50-59, 60-69 and 70+ years. The dynamic effect of the vaccination campaign on mortality rates was estimated by applying a negative binomial regression. The prevented and possible preventable deaths (observed deaths higher than expected) and potential years of life lost (PYLL) for each age group were obtained in a counterfactual analysis. RESULTS: During the first year of COVID-19 vaccination, 266 153 517 doses were administered, achieving 91% first-dose coverage. A total of 380 594 deaths were reported, 154 091 (40%) in 70+ years and 136 804 (36%) from 50-59 or 20-49 years. The mortality rates of 70+ decreased by 52% (rate ratio [95% CI]: 0.48 [0.43-0.53]) in 6 months, whereas rates for 20-49 were still increasing due to low coverage (52%). The vaccination roll-out strategy prevented 59 618 deaths, 53 088 (89%) from those aged 70+ years. However, the strategy did not prevent 54 797 deaths, 85% from those under 60 years, being 26 344 (45%) only in 20-49, corresponding to 1 589 271 PYLL, being 1 080 104 PYLL (68%) from those aged 20-49 years. CONCLUSION: The adopted aged-based calendar vaccination strategy initially reduced mortality in the oldest but did not prevent the deaths of the youngest as effectively as compared with the older age group. Countries with a high burden, limited vaccine supply and young populations should consider other factors beyond the age to prioritise who should be vaccinated first.

The COVID-19 Uninsured Program: Nearly 39 Million Vaccine Doses Were Funded, 2020-22.

The COVID-19 Uninsured Program, administered by the Health Resources and Services Administration (HRSA), reimbursed providers for administering COVID-19 vaccines to uninsured US adults from December 11, 2020, through April 5, 2022. Using HRSA claims data covering forty-two states, we estimated that the program funded about 38.9 million COVID-19 vaccine doses, accounting for 5.7 percent of total doses distributed and 10.9 percent of doses administered to adults ages 19-64.