Johnson & Johnson submitted an application to the Food and Drug Administration Thursday for an emergency use authorization for its experimental COVID-19 vaccine.
The FDA could grant that authorization within weeks. If authorized, it would give the U.S. a third COVID-19 vaccine, along with the vaccines from Pfizer-BioNTech and Moderna.
"Today's submission for emergency use authorization of our investigational single-shot COVID-19 vaccine is a pivotal step toward reducing the burden of disease for people globally and putting an end to the pandemic," Dr. Paul Stoffels, chief scientific officer at Johnson & Johnson, said in a press release.
If the FDA grants the company emergency use authorization, Stoffels said the company would be ready to begin shipping vaccines. It is unclear how many doses would be ready immediately, however Johnson & Johnson previously said it expects to supply 100 million doses to the U.S. by June.
The Johnson & Johnson vaccine, made in partnership with Janssen Pharmaceuticals, only requires basic refrigeration and is given as a single dose. Other vaccines, including Pfizer and Moderna's shots, as well as vaccines being studied from AstraZeneca and Novavax, require two doses.
In Phase 3 clinical trials, the Johnson & Johnson vaccine prevented all hospitalizations and deaths in people four weeks after they received the shot, the company said last week. Notably, these effects were observed in people infected with virus variants from the U.K. and South Africa, which can hinder vaccine efficacy.
Indeed, that was apparent when the Phase 3 clinical trial findings were broken down by region. In the U.S., the vaccine was 72% effective at preventing moderate to severe disease, while in South Africa, it was 57% effective.
When researchers looked just at the shot's effect on severe disease, it was shown to be 85% effective, globally.
On a call with reporters last week, Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said that keeping people out of the hospital and preventing severe illness is "the most important thing."
"If you can prevent severe disease in a high percentage of individuals, that will alleviate so much of the stress" on the health care system, Fauci said.
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Pfizer and Moderna's trials were specifically designed to examine the impact of two doses of vaccine. Johnson & Johnson's trial limited the research so far to one dose, though studies of a booster shot are ongoing.
Johnson & Johnson's vaccine uses an inactivated common cold virus, called an adenovirus, to teach the immune system to recognize and fight off SARS-CoV-2, the virus that causes COVID-19. This is a different approach than the Pfizer and Moderna vaccines, which use genetic material called messenger RNA, or mRNA, to train the immune system.
This story first appeared on NBCNews.com.