The impact of COVID-19 vaccination prior to SARS-CoV-2 infection on prevalence of long COVID among a population-based probability sample of Michiganders, 2020-2022.

To estimate the association between COVID-19 vaccination status at the time of COVID-19 onset and long COVID prevalence. We used data from the Michigan COVID-19 Recovery Surveillance Study, a population-based probability sample of adults with COVID-19 (n = 4695). We considered 30-day and 90-day long COVID (illness duration ≥30 or ≥90 days, respectively), using Poisson regression to estimate prevalence ratios (PRs) comparing vaccinated (completed an initial series ≥14 days before COVID-19 onset) to unvaccinated individuals (received 0 doses before COVID-19 onset), accounting for differences in age, sex, race and ethnicity, education, employment, health insurance, and rurality/urbanicity. The full unvaccinated comparison group was further divided into historic and concurrent comparison groups based on timing of COVID-19 onset relative to vaccine availability. We used inverse probability of treatment weights to account for sociodemographic differences between groups. Compared to the full unvaccinated comparison group, the adjusted prevalence of 30-day and 90-day long COVID were lower among vaccinated individuals [PR 30-day = 0.57(95%CI:0.49,0.66); PR 90-day = 0.42(95%CI:0.34,0.53)]. Estimates were consistent across comparison groups (full, historic, and concurrent). Long COVID prevalence was 40–60% lower among adults vaccinated (vs. unvaccinated) prior to their COVID-19 onset. COVID-19 vaccination may be an important tool to reduce the burden of long COVID. Post-acute COVID-19 syndrome; COVID-19; COVID-19 vaccines; Population-based CDC, Centers for Disease Control and Prevention; CI, Confidence interval; COPD, Chronic obstructive pulmonary disease; COVID-19, Coronavirus disease 2019; CVD, Cardiovascular disease; EHR, Electronic health record; IPTW, Inverse probability of treatment weight; MDSS, Michigan Disease Surveillance System; MI CReSS, Michigan COVID-19 Recovery Surveillance Study; mRNA, Messenger ribonucleic acid; NH, Non-Hispanic; PCR, Polymerase chain reaction; PR, Prevalence ratio; US, United States; WHO, World Health Organization. [ABSTRACT FROM AUTHOR]