Long-term Protection Associated With COVID-19 Vaccination and Prior Infection
Mark W. Tenforde, Ruth Link‐Gelles, Manish M. Patel
Abstract
COVID-19 vaccines are considered to have prevented an estimated tens of millions of SARS-CoV-2 infections and tens of thousands of COVID-19-related deaths in the US. Designing and interpreting postauthorization, observational COVID-19 vaccine effectiveness studies have also become increasingly complex due to effects of prior infection on the risk and severity of repeat infections, emergence of variants that evade vaccine-induced immunity, waning immunity, more vaccine products and dosing schedules, and heterogeneity in outcomes measured within and across studies. The proper design and interpretation of vaccine effectiveness studies have consequences for vaccine research and policy decisions and for the public's perception and trust of vaccines.