Health care giant Johnson & Johnson, with offices in Irvine, has received FDA approval to distribute a vaccine that requires just a single dose to protect against COVID-19.

The vaccine was found to be 85% effective at preventing severe disease, according to the company’s Phase 3 clinical trial.

Vaccines made by Pfizer and Moderna, in use since December, require two doses, while Johnson & Johnson’s vaccine does not.

Johnson & Johnson has a $1 billion deal to supply the U.S. government with 100 million doses of its vaccine by the end of June. The company, one of 900 medical and technology firms in Irvine, employs more than 1,500 people in Orange County, mostly in Irvine.