Over 58 million older adults globally have received at least one dose of a COVID-19 vaccine. COVID-19 vaccines, including boosters, are safe and effective overall. However, older adults, especially those with advanced dementia and other complex health conditions, are generally excluded from clinical trials and other studies of COVID-19 vaccines.

Because aging can change responses to vaccines as well as the severity of COVID-19, the effects of COVID-19 vaccines and boosters may differ in older adults versus younger and healthier people. Understanding how COVID-19 vaccines perform in an older population is important because older age and certain health conditions can reduce the effectiveness of vaccines. They can also worsen the severity of COVID-19.

In a study published in the International Journal of Population Data Science (IJPDS), researchers from Brown University, in collaboration with CVS Health and Walgreens, describe the COVid VAXines Effects on the Aged (COVVAXAGE) database that aims to address this critical gap in knowledge.

The COVVAXAGE database contains previously collected healthcare data on over 38 million persons in the United States who are beneficiaries of the US federal health insurance program, Medicare.

The database is among the largest of its kind and contains detailed healthcare information, including the type of vaccine products used (e.g., Pfizer-BioNTech or Moderna) and clinical conditions (e.g., dementia diagnosis), as well as follow-up information on COVID-19 diagnoses, and rare potential adverse events, like blood clots.

The database was created through a novel private-public partnership with CVS Health and Walgreens, the two largest pharmacy chains in the US that have locations in every state. Data are anonymised and held in a secure environment.

Dr. Kaleen Hayes, Assistant Professor at Brown University and lead author on the study, commented: “This large population-based database gives us the unique ability to provide real-world evidence on COVID-19 vaccines in older populations that haven’t been studied.”

The COVVAXAGE database has already been leveraged to study critical questions on COVID-19 vaccines, including the comparative effectiveness and safety of different mRNA vaccines in frail older adults, and racial and ethnic disparities in booster vaccination. Beneficiaries in the database are diverse, with over 2.6 million individuals aged ≥85 years and over 56% female and over 25% being Black, Hispanic, Asian, Native American, or other race or ethnicity.

The aims of the project are to examine the uptake, safety, and effectiveness of COVID-19 vaccines in older adults, particularly as booster vaccines have the potential to become routine practice in coming years. Investigators funded by the National Institute on Aging (NIA) who establish relevant data use agreements can access these data.


Click here to read the full open access article

Kaley Hayes, Assistant Professor, Department of Health Services, Policy and Practice, Brown University School of Public Health, USA

Hayes, K., Harris, D., Zullo, A., Djibo, D. A. ., Smith-Ray, R. L. ., Taitel, M. S., Singh, T. G., McMahill-Walraven, C., Chachlani, P., Wen, K., McCarthy, E. P., Gravenstein, S. ., McCurdy, S., Baird, K. E. ., Moran, D., Fenson, D. and Mor, V. (2023) “Data Resource Profile: COVid VAXines Effects on the Aged (COVVAXAGE)”, International Journal of Population Data Science, 8(6). doi: 10.23889/ijpds.v8i6.2170.