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Promising test results from two vaccine developers have addressed some key challenges in the COVID-19 pandemic and could provide a badly needed boost in the race to get ahead of the virus.

Interim data released this week from U.S. drug-makers Novavax and Johnson & Johnson highlighted several critical benefits. The Novavax vaccine was effective against the British and South African variants, while J&J’s offered complete protection against hospitalization and death after one dose. Both vaccines also don’t require super-cold storage and they can be kept in regular refrigerators for months.

The companies are seeking regulatory approval in several countries and they could be in production this spring. Once approved, they will be a welcome addition to the growing arsenal of vaccines already in widespread use from Pfizer-BioNTech, Oxford-AstraZeneca and Moderna. Canada has been relying on the Pfizer-BioNTech and Moderna vaccines but the federal government has ordered up to 76 million doses of the Novavax vaccine and 38 million of J&J’s.

The world is grappling with a surge in COVID-19 cases that has overwhelmed hospitals in many countries. Studies have shown that both variants are more contagious than the original version of the virus and that the British variant is more deadly.

Scientists said the J&J vaccine could be a breakthrough for overstretched public health agencies. “For countries looking to stop the pandemic and ease the pressure on the health system this is an unbelievable result and really groundbreaking,” said Saul Faust, a professor of infectious disease at the University of Southampton who worked on the J&J trials.

The J&J vaccine was tested on 43,783 people in eight countries. The overall results showed that the vaccine was 66-per-cent effective in preventing moderate to severe illness. In the U.S. arm of the trial, that number rose to 72 per cent, but it dropped to 57 per cent in South Africa. That’s lower than some of the other vaccines, which offered more than 90-per-cent protection against the older form of the virus after two doses.

Paul Stoffels, J&J’s chief scientific officer, said the most important findings were that the vaccine had 85-per-cent efficacy against severe sickness and provided 100-per-cent protection against hospitalization and death. That was across all countries, both variants and every age group. “What we also see is early onset of protection,” he said. “As of day 14 we see already significant increase in protection against severe disease.”

Dr. Faust cautioned against comparing efficacy percentages among vaccines and noted that protection can vary over time. “I wish from a clinical point of view the world would stop focusing on those, for me, minor differences whether it’s 70 per cent or 90 per cent,” he told a press briefing on Friday. “The key is that they are stopping people going into hospital and stopping death and [the J&J] vaccine does it on one dose.”

The Novavax vaccine, which requires two doses, is the first to show strong efficacy in clinical trials against the British and South African variants. Unlike the three vaccines currently in use, it isn’t based on novel technology and the manufacturing process is relatively simple. The vaccine has been tested on 15,000 people in Britain and 4,400 in South Africa. Interim data showed it was 85.6-per-cent effective against the British variant and 60-per-cent effective against the South African variant.

Paul Heath, director of the vaccine institute at the University of London who led the Novavax trials in Britain, played down concerns about the efficacy against the South African variant. “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,” he said during a press conference Friday.

Scientists acknowledged that there were still concerns. The lower protection rates against the South African variant for both vaccines mean that drug companies will have to be diligent in altering their ingredients to keep up. Dr. Stoffels said J&J was working on a booster shot for its vaccine and Novavax and the other companies have also begun testing new variations.

Taken together, the results offer a glimpse of what may be expected from all three of the vaccine platforms where Canada, among other countries, has placed its bets.

The Pfizer-BioNTech and Moderna vaccines introduce genetic instructions, called messenger RNA, which trigger the immune system by telling the body to make viral proteins that preview what the real virus will look like. So far, these vaccines have proved highly effective but they are also more expensive, owing to the fragility of the RNA molecules they contain.

The second platform is used by J&J and Oxford-AstraZeneca. It involves injecting a disabled form of another virus, called an adenovirus, to bring in the genetic information to make proteins found in COVID-19. Because the information is encoded as DNA rather than RNA these vaccines are more robust, but they haven’t demonstrated the same high efficacy. In contrast, the Novavax vaccine uses a laboratory-made version of the virus’s spike protein, the area that binds to human cells, and mixes in an adjuvant to boost to the body’s immune system.

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