Researchers behind the development of a new COVID-19 vaccine from U.S. drug-maker Novavax say it provides strong protection against the British and South African variants of the virus.
Interim results from trials involving 15,000 volunteers in the U.K. showed that the vaccine was 85.6 per cent effective against the British variant. Trials in South Africa involving 4,400 participants showed 60 per cent efficacy. Final results will be published in the next few weeks and British officials hope to have the vaccine approved and in circulation during the second half of the year. Canada has ordered up to 76 million doses of the vaccine which requires two injections.
The results “are great news, of course,” said Paul Heath, director of the vaccine institute at the University of London who led the U.K. trials. “We had reason to be concerned that the vaccine may not be quite so good against [the U.K.] variant but, in fact, the trial has really shown us that that is not a problem for the vaccine. The vaccine efficacy is pretty much the same regardless of whether it’s the new variant or the strain of the virus that we were dealing with before.”
In the British trials, 62 volunteers fell ill — 56 who had received a placebo and six who had been given the vaccine — resulting in an overall efficacy rate of 89.3 per cent. Just over half of those who got sick had the U.K. variant and the vaccine provided 85.6 per cent protection, the company said.
The South African trials had a separate focus on people living with HIV. The vaccine proved to be 60-per-cent effective in non-HIV volunteers. When HIV-positive participants were added, the effectiveness fell to 49.4 per cent. More than half of the COVID-19 cases in the trial involved the South African variant and most of the volunteers were non-HIV positive.
“That 60 per cent is really good,” said Dr. Heath. “I’d like it to be 100 per cent, of course, but to be fair and given our concerns, everyone is very pleased that it has come out with a very positive efficacy.”
Shabir Madhi, a vaccine expert at The University of the Witwatersrand, Johannesburg, who led the South African trials, also welcomed the results. “This is the first COVID-19 vaccine for which we now have objective evidence that it protects against the variant dominating in South Africa,” he said in a statement.
Unlike the vaccines currently in widespread use — from Pfizer-BioNTech, Oxford-AstraZeneca and Moderna — the Novavax vaccine is based on fairly standard technology. It uses a laboratory-made version of the virus’ spike protein, the area that binds to human cells, and mixes in an adjuvant to provide an extra boost to the body’s immune system. The Novavax vaccine can also be stored in regular refrigerators and it is easier to manufacture than the others. Dr. Heath also said the spacing of the doses can be flexible.
The trials were conducted on the basis of a 21-day interval between the first and second doses, but Dr. Heath said a longer delay was possible. “Certainly with a standard vaccine like this, I would have very little concern about extending the interval between doses because we know that works with these types of vaccines,” he said.
Britain and some other countries have started delaying the interval between shots of the other vaccines, which also require 21 day spacing between the first and second dose, in order to vaccinate more people. The move has been controversial and some scientists have expressed concern that it could affect the efficacy. However, Dr. Heath said the dosing regime of most standard vaccines, such as the cervical cancer vaccine, has been changed over the years and the effectiveness has increased.
The Novavax trials have been another boost to Britain’s vaccine program which has been among the most effective in the world. The government’s vaccines taskforce was an early backer of the Novavax project and it helped set up the trials last fall. As a result, Britain is expected to be the first country to approve the vaccine and the government has ordered 60 million doses. The vaccine will also be manufactured in Stockton-on-Tees in north-east England.
The vaccine is expected to be rolled out later in other countries, including Canada, once larger trials involving 30,000 volunteers in the U.S. have been completed. Those trials began in December.
The U.K. has already approved the Pfizer-BioNTech, Moderna and Oxford-AstraZeneca vaccines and the country has so far inoculated more than 7.4 million people, one of the highest rates in the world. “The Novavax vaccine will be a significant boost to our vaccination programme and another weapon in our arsenal to beat this awful virus,” said Health Secretary Matt Hancock.
Our Morning Update and Evening Update newsletters are written by Globe editors, giving you a concise summary of the day’s most important headlines. Sign up today.