ABSTRACT
BackgroundCOVID-19 has highlighted the need for new methods of pharmacovigilance. Here we use community volunteers to obtain systematic information on vaccine effectiveness and the nature and severity of breakthrough infections. MethodsBetween December 15, 2020 to September 16, 2021, 10,412 unpaid community-based participants reported the following information to an on-line registry: COVID-19 test results, vaccination (Pfizer, Moderna, or Johnson & Johnson), COVID-19 symptoms and perceived severity using a 4-point scale. COVID-19 infections were described for those who were 1) fully vaccinated, 2) partially vaccinated (received first of two dose vaccines or were <14 days post-final dose), or 3) unvaccinated. ResultsOf 8,554 who were vaccinated, COVID-19 infections were reported by 74 (1.0%) of those who were fully vaccinated and 198 (2.3%) of those who were partially vaccinated. Among the 74 participants who reported a breakthrough infection after full vaccination, the median time to reported positive test result was 104.5 days (Interquartile range: 77-135 days), with no difference among vaccine manufactures. One quarter (25.7%) of breakthrough infections in the fully vaccinated cases were asymptomatic. More than 97% of fully vaccinated participants reported no moderate/severe symptoms compared to 89.3% of the unvaccinated cases; and only 1.4% of fully vaccinated participants reported experiencing at least 3 moderate to severe symptoms compared to 7.8% in the unvaccinated. ConclusionPerson-generated health data, also referred to as patient-reported outcomes, is a useful resource for quantifying breakthrough infections and their severity, showing here that fully vaccinated participants report no or very mild COVID-19 symptoms. Trial registrationClinicaltrials.gov NCT04368065, EU PAS Register EUPAS36240
ABSTRACT
IntroductionOur objective was to describe and compare self-reported side effects of COVID-19 vaccines in the USA. MethodsA web-based registry enrolled volunteers who received a COVID-19 vaccine between March 19 -July 15, 2021. We collected self-reported short-term side effects, medical consultation, hospitalization, and quality of life impact following completed vaccination regimens (Pfizer, Moderna, J&J). ResultsWe recruited 6,966 volunteers who completed their full course of vaccination (median age 48 years, IQR 35.0-62.0; 83.6% female): Pfizer 3,486; Moderna 2,857; J&J 623. Few (3.1%) sought medical care for post-vaccination side effects. Hospitalization (n=17; 0.3%) and severe allergic reactions (n=39; 0.6%) also were rare. Those with autoimmune disease or lung disease were approximately twice as likely to seek medical care (adjusted odds ratio (aOR) 2.01 [95% CI: 1.39;2.92] and 1.70 [95% CI: 1.12;2.58] respectively). 92.4% of participants reported [≥]1 side effect (median 3), with injection site reactions (78.9%), fatigue (70.3%), headache (49.0%) reported most frequently. More side effects were reported after the second dose of two-dose vaccines (medians: 1 vs. 2 for Pfizer and 1 vs. 3 for Moderna for first and second doses respectively) versus 3 for J&Js single-dose vaccine. For the employed, the median number of workdays missed was one. Diabetics and those vaccinated against influenza were substantially less likely to report [≥]3 symptoms (aOR 0.68, 95% CI 0.56,0.82 and aOR 0.82, 95% CI 0.73,0.93, respectively.) DiscussionThe total side effect burden was, not unexpectedly, greater with two-dose regimens but all three vaccines appear relatively safe. Very few subjects reported side effects serious enough to warrant medical care or reported post-vaccination hospitalization. While these findings do not address possible long-term effects, they do inform on their short-term safety and tolerability and will hopefully provide some reassurance and positively inform the benefit-risk and pharmacoeconomic assessment for all three vaccines. Clinicaltrials.gov NCT04368065
