How effective is Johnson & Johnson's COVID vaccine? Here's what we know

PHILADELPHIA (WPVI) -- Within weeks, we could have a third COVID-19 vaccine authorized here in the United States. Johnson & Johnson's vaccine is just one dose and would be easier to ship and store than other approved vaccines.

Johnson & Johnson released new clinical trial results Friday, showing their one-dose vaccine is 85% effective at preventing severe disease due to COVID-19. In the U.S., it was found to be 72% effective at preventing infection with symptoms in the first place.

"The headline really does not do this justice," said Dr. Nina Gentile. She lead the clinical trial at Temple Health and says while the data still needs to be vetted, it is promising.

It shows good safety, with few side effects, but comparing it to the 94%-95% efficacy reported with the Pfizer and Moderna vaccines is like comparing apples to oranges. They were tested at different times and in different locations.

WATCH: Lead researcher talks about Johnson & Johnson's phase 3 clinical trial results
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Lead researcher talks about Johnson & Johnson's phase 3 clinical trial results



Johnson & Johnson's vaccine was tested at the height of the pandemic in the United States as well as in Latin America and South Africa, where concerning new variants of the virus are spreading.

"So to have data that includes people who were infected by those variants and see that it was protective against it is really remarkable. I think it's an opportunity here," said Dr. Gentile.

The company will now submit data to the FDA. It hopes to get emergency use authorization by the end of February.

If authorized, the company reports it can supply 100 million doses to the U.S. by June, which would bring a much-needed boost in supply.
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