About 13,700 Americans receiving the Johnson & Johnson COVID-19 vaccine experienced side effects, amounting to less than 0.18% of the nearly 8 million shots given so far, according to new federal data.
Almost all of the reactions — 97% — were not considered serious, according to a study released Friday by the Centers for Disease Control and Prevention.
The most frequent side effects were headache (34%), fever (34%), chills (33%), injection site pain (26%) and fatigue (24%). Four of 79 reports of anaphylaxis after vaccination were confirmed, while four are being reviewed.
However, 17 cases of blood clots were reported, including three deaths. The reports of blood clots prompted the CDC and Food and Drug Administration to halt the use of the J&J vaccine in mid-April while federal scientists investigated. The CDC lifted the pause after 10 days, saying that the benefits of the vaccine far outweigh the risk, but J&J and federal regulators plan to start warning recipients of the clotting risk.
Federal health officials have reviewed 88 reports of death following vaccination, with 26% of the deaths from cardiac arrest or cardiovascular disease. Details were not available for 34 of the people who died.
Forty-four women and 38 men died, while the sex of six people was not reported. The median age was 69, and the median time frame from vaccination to death was two days.
About one-third of 338,700 recipients participating in a follow-up survey said their reactions to the vaccine made them unable to perform normal daily activities such as work.
A separate CDC study released Friday found 64 anxiety-related events, including 17 reports of fainting among 8,624 Johnson & Johnson vaccine recipients from five mass vaccination sites.
