New large study provides 'clear evidence' for Pfizer vaccine safety

A new study published by The New England Journal of Medicine provides "clear evidence" for the safety of the Pfizer COVID-19 vaccine, which was just granted full approval by the Food and Drug Administration.
The study, a large one, took data from Israel's largest health care organization and compared vaccinated individuals to their unvaccinated peers, while also performing a similar analysis of people naturally infected by the coronavirus by matching them with those who hadn't been infected, to assess whether there was an increase in risk of adverse side effects.
The most significant risk difference for vaccinated folks was lymph node enlargement, which scientists expected. Notably, there was a small risk increase for myocarditis, or heart inflammation, but it was substantially lower than the increase for people who were diagnosed with COVID-19. In fact, COVID-19 infections increased the risk for numerous ailments in the study. Read the full results at The New England Journal of Medicine.
Subscribe to The Week
Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.

Sign up for The Week's Free Newsletters
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
Sign up for Today's Best Articles in your inbox
A free daily email with the biggest news stories of the day – and the best features from TheWeek.com
Tim is a staff writer at The Week and has contributed to Bedford and Bowery and The New York Transatlantic. He is a graduate of Occidental College and NYU's journalism school. Tim enjoys writing about baseball, Europe, and extinct megafauna. He lives in New York City.
-
5 worm-ridden cartoons about RFK. Jr and the CDC
Cartoons Artists take on vaccine advisers, medical quackery, and more
-
Will 2027 be the year of the AI apocalypse?
A 'scary and vivid' new forecast predicts that artificial superintelligence is on the horizon A 'scary and vivid' new forecast predicts that artificial superintelligence is on the horizon
-
Crossword: June 15, 2025
The Week's daily crossword puzzle
-
Kennedy ousts entire CDC vaccine advisory panel
speed read Health Secretary RFK Jr. is a longtime anti-vaccine activist who has criticized the panel of experts
-
RFK Jr. scraps Covid shots for pregnant women, kids
Speed Read The Health Secretary announced a policy change without informing CDC officials
-
New FDA chiefs limit Covid-19 shots to elderly, sick
speed read The FDA set stricter approval standards for booster shots
-
US overdose deaths plunged 27% last year
speed read Drug overdose still 'remains the leading cause of death for Americans aged 18-44,' said the CDC
-
Trump seeks to cut drug prices via executive order
speed read The president's order tells pharmaceutical companies to lower prescription drug prices, but it will likely be thrown out by the courts
-
RFK Jr.: A new plan for sabotaging vaccines
Feature The Health Secretary announced changes to vaccine testing and asks Americans to 'do your own research'
-
Unraveling autism: RFK Jr.'s vow to find a root cause
Feature RFK Jr. has vowed to find the root cause of the 'autism epidemic' in months. Scientists have doubts.
-
The sneaking rise of whooping cough
Under the Radar The measles outbreak isn't the only one to worry about