Novavax Says Its COVID Vaccine Is Extremely Effective

The first results from a large efficacy study of a new kind of COVID-19 vaccine are now out, and they are good. Very good.

According to Novavax, the vaccine's manufacturer, it had a 100% efficacy against the original strain of the coronavirus and 93% efficacy against more worrisome variants that have subsequently appeared.

In addition to efficacy, the PREVENT-19 (the PRE-fusion protein subunit Vaccine Efficacy Novavax Trial COVID-19) trial showed the Novavax vaccine was safe for users. Like other COVID-19 vaccines, it caused headaches, chills and muscle aches after injection, but few of these side effects were considered serious or severe.

The study involved 29,960 volunteers in the United States and Mexico. In the study, two-thirds of the volunteers received two shots of the vaccine and one-third received two shots of a placebo.

A total of 77 cases of COVID-19 occurred during the study: 63 in the placebo group and 14 in the vaccine group. According to the Novavax statement describing the results, none of the cases of COVID-19 in the vaccine group were related to the original strain of the virus, hence the 100% efficacy against the original strain.

The breakthrough cases were all caused by the newer, more worrisome variants, and all of the breakthroughs in the vaccine group were mild. By contrast, 10 in the placebo group were considered moderate and four severe. Novavax's statement did not specify which variants in particular were prevented.

The company says it intends to file for authorization from regulators in the U.S., Europe and the United Kingdom later this summer. Novavax says it will be able to deliver 100 million doses per month by the end of September and 150 million doses per month by the end of the year.

The Novavax vaccine is what's known as a protein subunit vaccine. All COVID-19 vaccines are based on something called the coronavirus spike protein. That's the protein that prompts the immune system to make antibodies to the virus.

The vaccines made by Moderna and Pfizer-BioNTech deliver the genetic instructions for the spike protein in the form of messenger-RNA, and the cells of the person receiving the vaccine make the spike protein. The Johnson & Johnson vaccine delivers those instructions using a viral vector, again relying on the vaccine recipient's cells to make the protein.

Novavax, on the other hand, makes the protein in cell cultures grown in giant bioreactors in manufacturing facilities and delivers the fully formed vaccine along with a substance for priming the immune system in its vaccine.

The Novavax vaccine was one of the vaccines chosen for development as part of Operation Warp Speed. The U.S. government is providing $1.75 billion to the company to support the vaccine's development.

It's not clear at this point whether the Food and Drug Administration is prepared to continue to grant emergency use authorizations for COVID-19 vaccines. The FDA may require Novavax to go through the standard licensure process, which can take considerably longer than an EUA.

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