Johnson & Johnson Announce Booster Shot Improves Immunity Two Months After First Dose

Johnson & Johnson announced Tuesday that its second dose of the COVID-19 vaccine increases protection by 94% after two months of receiving the initial shot.

The Phase 3 study found that Johnson & Johnson’s two-month booster shot gives 100% protection against severe cases of COVID-19, and 94% against moderate symptomatic cases in the U.S., according to a company press release. The current single-dose vaccine is 75% effective.

“Our large real-world evidence and Phase 3 studies confirm that the single-shot Johnson & Johnson vaccine provides strong and long-lasting protection against COVID-19-related hospitalizations. Additionally, our Phase 3 trial data further confirm protection against COVID-19-related death,” Mathai Mammen, global head of research and development at Johnson and Johnson, said in the press release.

In January, the pharmaceutical giant announced that trials showed the single dose of its COVID-19 vaccine was 66% effective against severe cases of the disease, according to The Wall Street Journal.

“We now have generated evidence that a booster shot further increases protection against COVID-19 and is expected to extend the duration of protection significantly,” Paul Stoffels, chief scientific officer at Johnson and Johnson, said in the press release.

The side effects of the booster are reported to be similar to those experienced with the single shot, according to the press release. Johnson & Johnson’s vaccine is currently the only single-shot jab offered in the U.S., while Pfizer and Moderna require two does.

Johnson & Johnson’s announcement comes after the Food and Drug Administration voted against approving Pfizer’s COVID-19 booster shot for U.S. citizens ages 16 and older. The panel approved the third shot for adults over the age of 65.