Novavax vaccine is 89% effective against Covid-19 in UK study

Still, the vaccine was less effective in a separate mid-phase study in South Africa, where another variant has spread. In South Africa, the Novavax injection in the study was approximately 49.4% effective against Covid-19. Preliminary results showed that more than 90% of the sick subjects for whom sequence data was available were infected with the new variant circulating in South Africa.

In light of lower efficacy in South Africa, Novavax said it has begun work on a modified version of its vaccine that better targets the strain identified there first, and plans to launch in the second quarter. to start testing.

Overall, however, the positive performance suggests that another vaccine will soon be joining the arsenal of shots available in some countries as health authorities grapple with limited supplies as they race to inoculate residents.

“We now have a vaccine, the first vaccine that has been shown to be effective not only in the prototype of the original Covid-19 strain, but also in two variants, one in the UK in South Africa,” said Stanley Erck , CEO of Novavax in an interview. “It’s the only data that shows we can get efficacy against all three.”

In the UK study, Novavax said that based on tests performed on 56 of 62 Covid-19 cases, the vaccine was found to be 95.6% effective against the original Covid-19 strain and 85.6% against the British tribe.

Novavax, which has never marketed a vaccine, released its study results via a press release. The data has not undergone the standard external expert screening prior to publication in a medical journal.

The Gaithersburg, Maryland, company said it has begun asking UK health regulators to use the company’s vaccine in the country.

Novavax said it would provide the new data to US regulators, which could lead to a permit in April. But U.S. regulators may not decide on the vaccine until they see the results of a third, ongoing late-stage study testing the injection in the U.S. and Mexico.

The study enrolled 16,000 people, towards a target of 30,000, and Novavax said it’s possible the first results could be reached by the end of March.

Pfizer vaccines Inc.

and its partner BioNTech SE,

as well as from Moderna Inc.,

are approved for use in the US, while an inclusion from AstraZeneca PLC and the University of Oxford is being approved in the UK

Novavax has one of the more advanced vaccines in development. Johnson & Johnson too,

who expects the results of the late phase, or phase 3, trial results for his vaccine by next week.

The urge to vaccinate has taken on new urgency since the rise of the strains in the UK and South Africa, as well as Brazil, which threaten to spread faster than the old version of the virus and evade some treatments.

Researchers have also been trying to see how well the vaccines protect against the new variants, and whether Covid-19 drugs will still work.

Moderna Inc. said this week it would develop a booster shot after lab tests showed the Covid-19 vaccine had a less neutralizing effect against the variant circulating in South Africa.

Moderna and Pfizer have said lab tests suggest their vaccines would still be effective against the variants identified in the UK and South Africa. Both variants have been found in the US, as well as the one identified in Brazil.

The Novavax vaccine contains proteins that resemble the “spike” proteins on the surface of the coronavirus.

Researchers designed the spike-like proteins released by the shot to trigger an immune response that can later defend against the true coronavirus if a vaccinated person is exposed to it.

Novavax makes the proteins in insect cells. The vaccine also contains an adjuvant, designed to enhance the immune responses generated by the vaccine, from the bark of an evergreen tree native to Chile.

The protein and adjuvant combination is generally similar in design to some vaccines against other diseases, such as the latest shingles introduced by GlaxoSmithKline PLC.

Novavax started the pivotal Phase 3 study in the UK in September and enrolled approximately 15,000 people.

The study tracked whether adults who received two doses of the vaccine, three weeks apart, experienced mild to severe Covid-19 at a slower rate than subjects who received a placebo, starting one week after the second dose.

The Pfizer-BioNTech and Moderna vaccines were more than 94% effective in Phase 3 studies, while the AstraZeneca vaccine was 62% effective in many subjects.

Novavax said there were “low levels” of serious side effects that were balanced between those who received the vaccine and those who received a placebo in the UK study.

In the smaller South African phase 2 study, Novavax compared its vaccine with a placebo in approximately 4,400 people. This study also included a subgroup of people who were HIV positive.

Excluding the results of people who are HIV positive, the vaccine was about 60% effective, Novavax said.

Health experts consider a flu shot to be 60% effective, although other vaccines can surpass 90% effectiveness. The U.S. Food and Drug Administration has said Covid-19 vaccines must be at least 50% effective.

Novavax’s phase 3 study of the vaccine in the US and Mexico began in late December. The start of the trial was delayed because Novavax encountered some manufacturing problems.

It was the first protein-based Covid-19 vaccine to be widely tested in the US.

The federal government agreed last July to provide $ 1.6 billion to Novavax to fund testing and manufacturing preparations for its vaccine, and to acquire 100 million doses.

In August, the UK government agreed to purchase 60 million doses of the Novavax vaccine and to work with the company on the phase 3 trial.

Last year, Novavax said that in a small, early study in healthy volunteers, the vaccine generated promising immune responses and was generally well tolerated.

If authorized for use, the vaccine could generate sales of $ 3.45 billion this year, according to the average estimate of analysts polled by FactSet.

—Gregory Zuckerman contributed to this article.

Write to Peter Loftus at [email protected]