Third doses of COVID-19 vaccines not associated with increase in reports of serious adverse events: study – CTV
April 17, 2022
A new study looking at data concerning around 48,000 people in the U.S. has found that third doses of mRNA vaccine, such as those from Pfizer or Moderna, are safe and did not cause any increase in reporting of serious adverse events.
The study, published in the journal JAMA Network Open on Thursday, found that third doses did not result in an increase in severe adverse events compared to earlier doses, but did come with an increase in low-severity adverse events, such as fatigue and nausea.
“Results from this cohort study suggest that a third dose of the same type of vaccination after a BNT162b2 or mRNA-1273 primary series is associated with safe outcomes,” the study stated.
The COVID-19 vaccines produced by Pfizer-BioNTech and Moderna were originally designed as two-dose regimes, supported by extensive clinical trials. As studies showed evidence of waning vaccine immunity, health experts began to suggest booster shots, which were found to be safe and effective. But there is still less data on these third doses than on the first and second doses, a gap in knowledge that researchers were hoping to close in this new study.
