Long COVID risk and pre-COVID vaccination in an EHR-based cohort study from the RECOVER Program
Brannock, MD; Chew, RF; Preiss, AJ; et al., Nature Communications
Published
May 2023
Journal
Nature Communications
Abstract
Long COVID, or complications arising from COVID-19 weeks after infection, has become a central concern for public health experts. The United States National Institutes of Health founded the RECOVER initiative to better understand long COVID. We used electronic health records available through the National COVID Cohort Collaborative to characterize the association between SARS-CoV-2 vaccination and long COVID diagnosis. Among patients with a COVID-19 infection between August 1, 2021 and January 31, 2022, we defined two cohorts using distinct definitions of long COVID-a clinical diagnosis (n = 47,404) or a previously described computational phenotype (n = 198,514)-to compare unvaccinated individuals to those with a complete vaccine series prior to infection. Evidence of long COVID was monitored through June or July of 2022, depending on patients' data availability. We found that vaccination was consistently associated with lower odds and rates of long COVID clinical diagnosis and high-confidence computationally derived diagnosis after adjusting for sex, demographics, and medical history.
Authors
M Daniel Brannock, Robert F Chew, Alexander J Preiss, Emily C Hadley, Signe Redfield, Julie A McMurry, Peter J Leese, Andrew T Girvin, Miles Crosskey, Andrea G Zhou, Richard A Moffitt, Michele Jonsson Funk, Emily R Pfaff, Melissa A Haendel, Christopher G Chute; N3C; RECOVER Consortia
Keywords
United States/epidemiology; Humans; Post-Acute COVID-19 Syndrome; COVID-19/epidemiology/prevention & control; COVID-19 Vaccines; Cohort Studies; SARS-CoV-2; Vaccination
Short Summary
RECOVER researchers wanted to understand whether being vaccinated before having COVID lowered the chance of developing Long COVID. They used electronic health records (EHR) to study the effect of vaccination using EHR for two groups of people who had COVID. One group was based on clinic data and represented more than 47,000 people. In this group, 695 were diagnosed with Long COVID in clinics and more than 26,000 were fully vaccinated. The other group represented almost 200,000 individuals who had COVID. The researchers used a computer program to estimate who might have Long COVID in this group based on their medical and symptom information. In this group, more than 86,000 people represented were fully vaccinated. The researchers made sure that the people in the vaccinated and unvaccinated groups were as similar to each other as possible in terms of the same sex, age, race, and medical history.
To test whether vaccination lowered the chance of developing Long COVID, they made comparisons within each group. They used several different definitions of Long COVID and several different statistical tests to figure out whether vaccination status affected Long COVID. For both of the study groups and for all definitions of Long COVID and each statistical test in the analysis, the researchers got the same answer: people who were vaccinated before having COVID were less likely to develop Long COVID.