FDA Authorizes Johnson & Johnson's One-Shot COVID-19 Vaccine

A third COVID-19 vaccine is on the way, and this one requires only one shot for immunization.

The Food and Drug Administration authorized Johnson & Johnson's vaccine for emergency use Saturday, a day after a panel of advisers to the agency voted unanimously (22-0) in its favor.

"The authorization of this vaccine expands the availability of vaccines, the best medical prevention method for COVID-19, to help us in the fight against this pandemic, which has claimed over half a million lives in the United States," said a statement by acting FDA Commissioner Janet Woodcock.

The Johnson & Johnson vaccine was tested in an international study of about 40,000 people, half of whom got the vaccine and half of whom got a placebo. The study found the company's vaccine to be 66% effective overall in preventing moderate to severe COVID-19 disease. For disease judged severe or critical, the effectiveness was 85%. The study was conducted in the U.S., South America and South Africa.

The main study included in the company's application found that 28 days or more after immunization, the Johnson & Johnson vaccine prevented hospitalizations and deaths related to COVID-19.

The overall efficacy figures are lower than Pfizer's 95% in preventing COVID-19 disease and 94% for Moderna. But direct comparisons are challenging because of differences in the clinical trials and emergence of new strains of the coronavirus.

The Johnson & Johnson vaccine "is very effective ... at preventing severe disease after a single dose and it induces the kind of response, so-called cellular immune response, that looks like it's going to have fairly long-lived memory, which is all good," Dr. Paul Offit, a member of the FDA's advisory panel, told NPR's Scott Simon on Weekend Edition Saturday. "This certainly provides protection against what you care about, which is hospitalization, ICU admission and death. It's virtually 100% effective at doing that." Offit is also director of the Vaccine Education Center at the Children's Hospital of Philadelphia.

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—Scott Hensley, NPR