COVID-19 vaccination timing, relative to acute COVID-19, and subsequent risk of long COVID
Summary Background Vaccination is a vital tool in preventing acute COVID-19 and may confer additional protection against Long COVID, although it is unclear whether this protection wanes over time. Methods We assessed electronic health record (EHR) data from a national, retrospective cohort of patients, comparing the 12-month cumulative incidence of Long COVID (ICD-10 code U09.9) among (A) patients who were vaccinated versus unvaccinated (two or more versus zero doses) and (B) patients diagnosed with acute COVID-19 1–3 months, 3–5 months, or 5–7 months after vaccination. Findings In our binary cohort (n = 519,980), we found that patients who were vaccinated had a lower risk of Long COVID (adjusted risk ratio 0.84 (0.81, 0.88)) or mortality (adjusted risk ratio 0.83 (0.81, 0.86)) than patients who were unvaccinated. In our longitudinal cohort (n = 1,085,291), we did not find significant heterogeneity in Long COVID risk during the seven months following vaccination. Interpretation We found that COVID-19 vaccination was protective against Long COVID, and we did not observe a significant waning of this protection within seven months after vaccination. Funding This research was financially supported by the 10.13039/100000060National Institute of Allergy and Infectious Diseases (1K01AI182501 to Zachary Butzin-Dozier) and a Global Development grant (OPP1165144) from the 10.13039/100000865Bill & Melinda Gates Foundation to the 10.13039/100005595University of California, Berkeley, CA, USA. Individual authors were supported by the following funding sources: 10.13039/100000025NIMHR01131542 (PI Rena C. Patel), Jerrod Anzalone is supported by the 10.13039/100000057National Institute of General Medical Sciences, U54 GM115458, which funds the Great Plains IDeA-CTR Network. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.