Most third doses of mRNA COVID-19 vaccines elicit side effects in line with that of the second dose, according to a CDC report.
The study analyzed immunocompromised recipients of the Pfizer-BioNTech and Moderna COVID-19 vaccine recipients eligible for a third dose.
It pulled data from 22,191 V-safe registrations. V-safe is a CDC-created smartphone-based system for tracking adverse events. Just under one-third (31.8%) of participants reported health impacts, while 28.3% said they could not perform routine daily activities — most often on the day following receipt of the third dose.
Referencing the report at a White House briefing, CDC Director Dr. Rochelle Walensky, concluded “COVID-19 vaccine booster doses so far are well tolerated”
Injection site reactions were slightly more common among the mRNA vaccine recipients than after receiving the second dose. Systemic reactions were somewhat less common post-third dose for both Pfizer-BioNTech and Moderna vaccine recipients.
The study authors concluded that the “initial findings indicate no unexpected patterns of adverse reactions after an additional dose of COVID-19 vaccine.” However, they recommended additional monitoring of safety signals.
The study period was August 12 to September 19, 2021.