Pfizer and its partner BioNTech have asked U.S. regulators for full approval of their COVID19 vaccine, a milestone in their effort to make the shot a sustainable revenue source that goes well beyond its current standing as an emergency product.

On Friday, the companies became the first COVID-19 vaccine-makers to submit a biologics license application to the U.S. Food and Drug Administration. Their vaccine is one of three — along with shots made by Moderna and Johnson & Johnson — that hold an emergency use authorization in the U.S., a designation that can be revoked at any time and lasts only as long as the state of emergency itself.

In submitting a BLA, Pfizer and BioNTech will subject their vaccine to greater scrutiny by the FDA, potentially helping to offset worries by some Americans that the shot may have been produced too quickly to guarantee its longterm safety. Data to support the application will be submitted to the regulator on a rolling basis in coming weeks.

If cleared, the companies would be able to begin marketing the product to the general public. The full approval would also allow more employers to begin mandating vaccination.

Moderna says it plans to initiate a rolling submission for a BLA for its COVID-19 vaccine this month.

The submission follows the “tremendous progress” they have made in delivering vaccines to millions of Americans and is the next step in a “rigorous FDA review process,” the companies said a statement.

As part of the application, they have submitted nonclinical and clinical data, including the most recent analysis from the Phase 3 clinical trial, where the vaccine’s efficacy and safety profile were observed for as long as six months after the second dose. The duo will also submit required manufacturing and facility data in the coming weeks.

The companies will first seek approval for the vaccine’s use in individuals 16 years of age and older, but also intend to submit a supplemental biologics license application for those aged 12 to 15 once the required data is available.

Peter Marks, director of the

FDA’s Center for Biologics Evaluation and Research, said in April that the review process typically takes six months, but that U.S. regulators would attempt to move faster than that.

The Pfizer-BioNTech vaccine was designed using messenger RNA technology. It works by instructing cells in the body to generate the spike protein that initiates the coronavirus infection, spurring an immune response.

On April 1, Pfizer and BioNtech reported follow-up data from a final-stage trial of 46,307 people showing the vaccine was

91.3 percent effective in preventing symptomatic cases starting one week after the second dose for as long as six months. In the U.S. alone, the efficacy rate was 92.6 percent.

Countries around the world are now reporting real-world data showcasing that the vaccine might handle variants.

In Qatar, for example, the twoshot regimen proved to be nearly 90 percent effective at preventing infection with B.1.1.7, and about 75 percent against the B.1.351 strain, according to analysis run on a national database of more than 200,000 people.