The Food and Drug Administration announced Wednesday that it has authorized a booster shot for Novavax’s Covid-19 vaccine.
Unlike the latest boosters from Pfizer-BioNTech and Moderna, which target both the original strain of SARS-CoV-2 and the Omicron BA.4/5 variants, the Novavax booster only targets the original strain. The company announced in late May that it was studying an Omicron-targeting strain, as well as a bivalent booster. But results of that work have not been revealed to date.
The booster shot is authorized for people 18 and older who, for medical or accessibility reasons, cannot take one of the bivalent messenger RNA Covid boosters, or who otherwise would not take a booster.
The booster shot is to be given at least six months after the administration of the second dose of a primary series of Covid vaccine.
The director of the Centers for Disease Control and Prevention, Rochelle Walensky, will have to recommend use of the vaccine before booster doses can be administered. That is expected to happen soon.
Novavax has presented data to the FDA that it said shows that its vaccine induces a broadly cross-protective response to various strains of SARS-2, including Omicron variants BA.1, BA.2, and BA.5. Data from the CDC indicate that BA.5 remains the dominant virus strain at present, though a half-dozen or so other Omicron variants are starting to replace it. BA.1 and BA.2 viruses no longer appear to be circulating in this country.
Novavax’s Covid vaccine showed highly favorable results in initial trials, with efficacy close to that shown by the mRNA vaccines. The Novavax vaccine is made using a different approach, employing recombinant nanoparticle technology. Its vaccine also uses an adjuvant, a compound that boosts the immune response the vaccine generates.
The vaccine, which is stored at fridge temperature, is given as a primary series as two doses administered three weeks apart.
Prior to the pandemic Novavax was seen as a company with a promising technology, but no proven track record — having never brought a vaccine to market — and no production facilities of its own. It has struggled mightily to produce its product since it entered the race to develop a Covid vaccine, only earning FDA authorization for its vaccine in July, a full 19 months after Pfizer and Moderna.
It has been hoped that the vaccine would entice people who have resisted getting mRNA vaccines to get vaccinated against Covid, but to date the number of takers in this country has been low. The latest data from the CDC shows that just over 35,000 doses of the vaccine have been administered. More than 372 million doses of Pfizer’s vaccine and nearly 236 million doses of Moderna’s vaccine have been given in the U.S.
Novavax has been approved in at least two countries — Canada and South Korea — and has been authorized for emergency use in a number of others, including Israel, Taiwan, Switzerland, the United Kingdom, South Africa, New Zealand, and in the European Union.
∼ Correction: An earlier version of this article incorrectly stated the Novavax booster was not available to people who had received an mRNA vaccine as their primary series.
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