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

However, the vaccine was less effective in a separate mid-stage study in South Africa, where another variant spread. In South Africa, the Novavax shot was approximately 49.4% effective compared to Covid-19 in the study. Preliminary results showed that more than 90% of the sick subjects for whom the sequence of data was available were infected with the new variant that had spread in South Africa.

In view of the lower efficacy in South Africa, Novavax said it was starting work on a modified version of the vaccine that would better target the strain identified for the first time, and plans to launch in the second quarter.

Overall, however, the positive performance suggests that another vaccine will soon join the arsenal of available shots in some countries, as health authorities struggle with limited supplies while trying to vaccinate the residents.

“We now have a vaccine, the first vaccine that is not only effective in the prototype Covid-19 original strain, but in two variety strains, one in the United Kingdom, one in South Africa,” said Stanley Erck, CEO of Novavax, said in an interview. “It’s the only data that shows we can be effective against all three.”

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

Novavax, which has never launched a vaccine before, announced its study results via press release. The data did not undergo the standard test by external experts preceding in a medical journal.

The company Gaithersburg, Md., Said it had begun the process of requesting that British health regulators remove the use of the vaccine in the country.

Novavax said it would provide the new data to U.S. regulators, which would authorize by April. But it is possible that U.S. regulators will not decide on the vaccine until they see the results of a third, ongoing late-study study testing the shot in the U.S. and Mexico.

The study enrolled 16,000 people, which was a target of 30,000, and Novavax said the possible initial results would possibly be by the end of March.

Pfizer vaccinations Inc.

and its partner BioNTech SE,

as well as from Moderna Inc.,

authorized for use in the US, while a survey of AstraZeneca PLC and the University of Oxford in the UK is being cleared

Novavax has one of the more advanced vaccines being developed. So does Johnson & Johnson,

which expects the trial results of the late stage, or Phase 3, to be released by next week.

The vaccination process has become urgent again since the emergence of the strains in the United Kingdom and South Africa, as well as Brazil, which threatens to spread faster than the old version of the virus and evade some treatments.

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

Moderna Inc. said this week that it would develop a shot after laboratory tests showed that the Covid-19 vaccine was less neutralizing against the variant circulating in South Africa.

Moderna and Pfizer said laboratory tests indicated that their vaccines would still be effective against the variants identified in the UK and South Africa. Both variants have been detected in the US, just as in Brazil.

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

Researchers have designed the peak-like proteins produced by the shot to elicit an immune response that can later defend against the real coronavirus when a vaccinated person is exposed to it.

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

The protein-supplement combination is usually similar to the design of some vaccines against other diseases, such as the latest shingles from GlaxoSmithKline PLC.

Novavax launched the important Phase 3 UK study in September, enrolling around 15,000 people.

The trial looked at whether adults who received two doses of the vaccine, three weeks apart, experienced a lower dose than Covid-19 at a slower rate than the 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 trials, while AstraZeneca’s vaccine was 62% effective in many study subjects.

According to Novavax, there was a low level of serious side effects balanced between those receiving the vaccine and those receiving a placebo in the UK study.

In the smaller, phase 2 South African study, Novavax compared the vaccine to placebo in approximately 4400 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 work well if it is 60% effective, although other vaccines can reach 90% effectiveness. The U.S. Food and Drug Administration said Covid-19 vaccines should be at least 50% effective.

Novavax’s Phase 3 study on the vaccine in the US and Mexico began in late December. The start of the trial was delayed because Novavax experienced some manufacturing issues.

It was the first protein-based Covid-19 vaccine to do large-scale US tests.

The federal government agreed last July to provide $ 1.6 billion to Novavax to help fund the preparation of the vaccine and obtain 100 million doses.

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

Last year, Novavax said that at an early stage of healthy volunteers, the vaccine elicits a promising immune response and that it is generally well tolerated.

If allowed to use, the vaccine could sell for $ 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 by [email protected]