NEW YORK (NYTIMES) - The Centres for Disease Control and Prevention (CDC) on Tuesday (July 19) recommended that a newly authorised vaccine from Novavax be used as an option for adults seeking a primary immunisation against the coronavirus.
Dr Rochelle Walensky, the CDC's director, signed off on the recommendation of a panel of vaccine experts that had unanimously endorsed the vaccine Tuesday afternoon.
The decision removes the final regulatory hurdle for the fourth Covid-19 shot authorised in the United States.
The Novavax vaccine is expected to play a limited role in the country's immunisation campaign, at least initially.
Last week, the Food and Drug Administration (FDA) authorised it as a primary immunisation for adults, but has not yet considered it for a booster shot.
Novavax, a Maryland pharmaceutical company, received significant federal funding to develop its shot but fell far behind in the vaccine race. Even so, it is hoping the shot will appeal to Americans who have declined to be vaccinated.
Some 26 million to 37 million adults in the United States have not yet received a coronavirus vaccine, according to survey data presented at the panel's meeting by Dr Katherine Fleming-Dutra of the CDC.
But in the countries where it has been available for months, Novavax's shot has yet to have a significant effect on vaccination rates.
Novavax said in its presentation to the panel Tuesday that just more than 1 million doses of its vaccine had been administered worldwide through the end of June, a tiny fraction compared with the reach of competing shots.
The Biden administration said last week that it would buy 3.2 million doses of Novavax's two-shot vaccine, enough to fully vaccinate 1.6 million people in the United States.
The vaccine is not yet available in pharmacies and other clinics that administer shots.
Novavax said in a news release after the panel's vote that the FDA had signed off on the first doses intended for the United States and that the company expects to ship its vaccine to a distribution centre "in the coming days."
With two doses spaced three weeks apart, the vaccine was found to be highly protective against infection and severe disease from the coronavirus in clinical trials.
But those were conducted before the emergence of the Omicron variant, which has sharply reduced the effectiveness of other authorised vaccines in preventing infections.
Novavax's vaccine works differently from the three Covid-19 vaccines previously authorised in the United States.
It provokes an immune response with nanoparticles made up of proteins from the surface of the coronavirus that causes Covid-19. Similar protein-based vaccines have been used globally for decades.
Dr Evelyn Twentyman of the CDC presented results from a survey suggesting that relatively few unvaccinated Americans would choose Novavax.
Sixteen per cent of unvaccinated respondents said they "probably" or "definitely" would get a protein-based Covid-19 vaccine, and 50 per cent of unvaccinated respondents said they "probably" or "definitely" would not.
At the meeting Tuesday, CDC officials reviewed clinical trial data that has linked the vaccine to an elevated but small risk of developing forms of heart inflammation known as myocarditis and pericarditis.
Dr Filip Dubovsky, chief medical officer at Novavax, said at the meeting that the company has been monitoring cases of heart inflammation in countries where the vaccine was already authorised.
Surveying just more than 1 million doses, the company has identified 17 definite or probable cases of myocarditis and pericarditis, he said.