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Evaluation of protection by COVID-19 vaccines after deployment in low and lower-middle income countries
John Clemens1,2, Asma Binte Aziz1,3, Birkneh Tilahun Tadesse1
1International Vaccine Institute, Seoul, South Korea.
Insights
COVID-19 vaccine effectiveness and impact studies are crucial for low and middle-income countries (L/MICs). Current research in L/MICs is limited, highlighting a neglected global priority for vaccine deployment.
Area of Science:
- Global Health
- Vaccinology
- Epidemiology
Background:
- COVID-19 vaccine availability and uptake in low and middle-income countries (L/MICs) significantly trail behind wealthier nations.
- Vaccines utilized in L/MICs often exhibit lower efficacy compared to those in high-income countries.
- Successful COVID-19 control via vaccination necessitates monitoring both individual vaccine effectiveness and population-level impact, including herd protection.
Purpose of the Study:
- To highlight the critical need for vaccine effectiveness and impact studies in L/MICs.
- To address the unique medical, demographic, and health system factors influencing vaccine performance in L/MICs.
- To underscore the current neglect of post-deployment vaccine studies in these regions.
Main Methods:
- Systematic review of published literature on COVID-19 vaccine effectiveness.
- Identification and analysis of studies conducted globally, with a specific focus on L/MICs.
- Assessment of the availability of vaccine impact studies in L/MICs.
Main Results:
- A total of 58 studies with 85 vaccine effectiveness evaluations were identified globally.
- Only three effectiveness studies were conducted in L/MICs.
- No vaccine impact studies were identified in L/MIC settings.
Conclusions:
- There is a significant gap in research on COVID-19 vaccine effectiveness and impact in L/MICs.
- Post-deployment studies are essential for understanding and optimizing vaccine performance in diverse populations.
- Addressing this neglected global priority is crucial for equitable and effective pandemic control.
Abstract:
The availability and use of vaccines for the coronavirus disease 2019 (COVID-19) in low and middle-income countries (L/MICs) lags far behind more affluent countries, and vaccines currently used in L/MICs are predominantly of lower efficacy. As vaccines continue to be rolled out in L/MICs, successful control of COVID-19 by vaccines requires monitoring both of vaccine protection of vaccinees (effectiveness) and of the entire targeted populations, including vaccine herd protection of non-vaccinees (impact). To be of greatest relevance to L/MICs, there is the need to address the distinctive medical and demographic features of populations, health systems, and demography that may greatly affect vaccine performance in these settings. We identified 58 published studies that included 85 evaluations of the effectiveness of different COVID-19 vaccines globally. Only three were done in L/MICs, and no impact studies were identified in these settings. Post-deployment studies of the protection by COVID-19 vaccines rolled out in L/MICs constitute an important but currently neglected global priority.
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