CNN  — 

The US Food and Drug Administration on Wednesday authorized Novavax’s Covid-19 vaccine for emergency use in adults. It is the fourth coronavirus vaccine available in the United States, and it uses a different type of vaccine technology than the shots already available.

Novavax’s vaccine will be available as two-dose primary series for people 18 and older.

The FDA’s independent Vaccines and Related Biological Products Advisory Committee voted in favor of authorization of the vaccine June 7, saying that the benefits of the vaccine outweigh its risks for adults. It is also being used in 170 other countries.

The shots can’t be administered until the US Centers for Disease Control and Prevention’s independent vaccine advisers weigh in on whether to recommend the vaccine and the CDC director has signed off on the recommendation. The CDC’s Advisory Committee on Immunization Practices is scheduled to meet July 19.

Like more familiar vaccines such as hepatitis B and pertussis, the Covid-19 vaccine is protein-based, using harmless protein fragments of the virus to teach the immune system how to spot the virus and fight it off. The vaccine was created out of a genetic sequence of the first strain of the coronavirus.

Unlike some other Covid-19 shots, Novavax’s vaccine can be stored in standard refrigeration.

About 1 in 3 Americans has still not been vaccinated against Covid-19, more than 100 million people. Many officials and health care workers hope that a vaccine like Novavax’s, which uses more familiar technology, may be enough to persuade people who’ve been hesitant to get inoculated.

“We believe that some portion of those 100 million people are waiting for our vaccine. And if you look at my in-basket, every day as I come to the office, you’ll see that there are quite a few of those people who are who are saying ‘let’s get this vaccine approved. I want it.’ So I don’t know what the what the portion of that 100 million people is, but but I think it’s not insignificant,” Novavax President and CEO Stanley Erck told CNN.

In addition to the primary series of shots, he says, the company hopes to receive authorization soon to use its shots as boosters to other vaccines.

“We’ve talked with the FDA quite a bit about this,” Erck said. “I believe the FDA will be addressing that approval within weeks.”

Late-stage trials found that the efficacy of the vaccine against mild, moderate and severe disease is 90.4%, according to the company. There is not sufficient evidence to evaluate the impact of the vaccine on transmission of the virus.

Novavax also announced in early July that its vaccine shows “broad” immune response to currently circulating variants, including Omicron subvariants BA.4/5.

Novavax’s vaccine was developed with funding from the federal government’s Operation Warp Speed.

On Monday, the Biden administration announced that it had secured 3.2 million doses of the Novavax vaccine.

The company said Wednesday that it expects the vaccine to be available quickly, pending signoff from the CDC.

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“We have vaccine that we’ve manufactured for the US. It is shipped and waiting in the warehouse,” Erck said. “The government has been very anxious to get these doses into their distribution system.

“My anticipation is that it will get widely distributed quickly.”

Erck also said the company was planning to offer vaccines to adolescents and children as young as 2 years. Data on the efficacy of kids’ shots will be available “in the coming months,” and Novavax hopes to offer shots to children later this year.