• The FDA recommended J&J's vaccine for emergency use authorization
  • Common side effects of the J&J vaccine are similar to that of the Pfizer and Moderna vaccines
  • The J&J vaccine did not cause anaphylaxis during the clinical trial

The U.S. Food and Drug Administration on Wednesday published a report of the most common side effects seen in trial participants who received Johnson & Johnson’s one-shot COVID-19 vaccine.

In the report, FDA indicated that the J&J coronavirus vaccine is safe and 85% effective in preventing severe cases of the novel coronavirus. They also endorsed the vaccine for emergency use authorization. If approved, J&J will be the third vaccine given authorization for use in the United States.

Side effects seen in J&J clinical trial participants included pain in the injection site, which was reported by 48.6% of participants; headache, 38.9%; fatigue, 38.2%; and muscle pain or myalgia, 33.2%.

Fewer participants reported experiencing skin redness and swelling after receiving the J&J vaccine, the FDA report said.

Most participants who developed adverse reactions to the vaccine were people between the ages of 18 and 59. The side effects usually lasted a couple of days after the shot.

15 cases in the vaccine group developed “embolic and thrombotic events” or blood clots. Researchers at the clinical trial also reported six cases of tinnitus, or a buzzing noise in at least one ear, among the vaccine recipients.

The FDA staff found two reports of Bell’s palsy— a condition that causes half of the face to droop. However, they found no cases of anaphylaxis — a severe allergic reaction that may cause hives, low blood pressure, weak pulse, vomiting or breathing difficulties.

The FDA’s report comes two days before the Vaccines and Related Biological Products Advisory Committee are scheduled to discuss whether to grant J&J emergency use authorization. It is expected that the panel will grant the company’s application for emergency use.

"The FDA went so far as to say the vaccine has a 'favorable safety profile with no specific safety concerns identified that would preclude issuance of an EUA," John Grabenstein, a former executive director of medical affairs for vaccines at Merck, said. “In other words, green light.”

Johnson & Johnson said the company is ready to provide approximately 20 million shots by the end of March, along with an additional 100 million doses over the summer.

Johnson & Johnson vaccine
The Johnson & Johnson vaccine is pictured. GETTY IMAGES NORTH AMERICA / Michael Ciaglo