COVID-19 vaccines are more effective at reducing the risk of COVID-19 hospitalizations compared to having a prior infection but no vaccination. The Centers for Disease Control and Prevention’s (CDC’s) VISION Network carried out the study of 7,000+ adult hospitalizations from January–September 2021, and has released results in a new Morbidity and Mortality Weekly Report: Laboratory-Confirmed COVID-19 Among Adults Hospitalized with COVID-19-Like Illness with Infection-Induced or mRNA Vaccine-Induced SARS-CoV-2 Immunity — Nine States, January–September 2021. Westat coauthors include Kristen A. Butterfield, M.P.H., Duck-Hye Yang, Ph.D., Sarah E. Reese, Ph.D., Patrick K. Mitchell, Sc.D., Elizabeth A. Rowley, Dr.PH, Matthew E. Levy, Ph.D., Rebecca J. Birch, M.P.H., and Sarah W. Ball, Sc.D.
Researchers analyzed electronic health record (EHR) data on COVID-like illness associated with hospitalizations among adults during this time period. Unvaccinated individuals with a prior COVID-19 infection were 5.49 times more likely to be hospitalized with laboratory-confirmed COVID-19 than those individuals who were fully vaccinated with 2 doses of either the Pfizer-BioNTech or Moderna vaccine.
The benefit of vaccination compared to infection-only appeared to be higher for those receiving Moderna compared with receiving Pfizer-BioNTech vaccine, and also trended higher for adults aged ≥65 years than those aged 18–64 years.
VISION VE, a virtual network, brings together sites to efficiently pull EHR data related to COVID vaccine and illness. Westat is the VISION Data Coordinating Center (VISION DCC), in partnership with 7 clinical sites, to collect retrospective EHR data using a common protocol.