Pfizer releases new data showing that side effects are similar to the second dose
A health care worker administers a third dose of the Pfizer-BioNTech Covid-19 vaccine at a seniors’ living facility in Worcester, Pennsylvania, U.S., on Wednesday, August 25, 2021.
Hannah Pierre | Bloomberg | Getty Images
The side effects of the Covid booster shots are similar to those felt after the second dose and are likely to affect young adults, Pfizer said in new data submitted to the US Food and Drug Administration as it seeks approval to distribute booster shots across the United States. .
Pfizer’s Phase III stimulant study, which included a group of nearly 300 participants between the ages of 18 and 55, found that 63.7% experienced fatigue after getting their boosters, 48.4% experienced headaches, and 39.1% experienced muscle pain. The majority of reactions to the booster were mild or moderate in severity, the company said in a 52-page report released by the agency on Wednesday. The company, along with BioNTech, is seeking emergency FDA approval to administer third doses for people 16 and older across the United States.
Pfizer previously evaluated side effects in 2,682 second-dose recipients aged 16 to 55 and found that 61.5% experienced fatigue, 54% experienced headaches and 39.3% experienced muscle pain.
The study also tracked adverse events among 306 recipients of the booster, 44 of whom developed at least one unexpected side effect. The most common adverse event, swollen lymph nodes, appeared in 16 of the participants.