Novavax is not an MRNA vaccine...so is it better for safety n efficacy?
Novavax COVID-19 vaccine works, according to early trial results, but less so against new variants
Posted Fri
A vial of the Phase 3 Novavax coronavirus vaccine
Novavax expects to deliver the initial doses to Australia by mid-2021.(AP: Alastair Grant)
Share
Novavax, one of three companies the Federal Government has struck a deal with to distribute COVID-19 vaccines in Australia, said its offering appears 89 per cent effective based on early findings from a British study.
Key points:
A trial of 15,000 people in Britain is still underway, but an interim analysis found 62 participants so far have been diagnosed with COVID-19
Only six of the unwell participants got the vaccine and the rest received dummy shots
More than half of the participants who became infected in the UK trial had the mutated version of the virus
Findings based on the trial also found that the vaccine seems to work — although not as well — against new mutated versions of the virus circulating in the UK and South Africa.
While the numbers are still very small, the 89 per cent figure is based on the combination of the vaccine being close to 96 per cent effective against the older coronavirus strain and nearly 86 per cent effective against the new variant.
The announcement comes amid worry about whether a variety of vaccines being rolled out around the world will be effective against new variants.
The study of 15,000 people in Britain is still underway, but an interim analysis found 62 participants so far have been diagnosed with COVID-19 — only six of them in the group got the vaccine and the rest received dummy shots.
The infections occurred at a time when Britain was experiencing a jump in COVID-19 caused by a more contagious variant.
A preliminary analysis found over half of the UK trial participants who became infected had the mutated version.
The findings are based on cases that occurred at least a week after the second dose.
"Both those numbers are dramatic demonstrations of the ability of our vaccine to develop a very potent immune response," Novavax CEO Stanley Erck said in a call with investors.
Protection against new variant in South Africa
Experts say any prediction on a vaccine timeframe is still an 'educated gamble'.
It's still unclear whether vaccines being rolled out around the world will be effective against new variants.(AAP: Glenn Hunt)
Scientists have been even more worried about a variant first discovered in South Africa that carries different mutations.
The South African study included some volunteers with HIV.
Among the HIV-negative volunteers, the vaccine appears 60 per cent effective.
When including volunteers with HIV, the overall protection was 49 per cent, the company said.
While genetic testing still is underway, so far about 90 per cent of the COVID-19 illnesses found in the South African study appear to be the new mutant strain.
More concerning is what the study showed about a totally different question — the chances of people getting COVID-19 a second time, said the leader of the South African study, Shabir Madhi of the University of the Witwatersrand in Johannesburg.
Tests suggested that nearly a third of the study participants had been previously infected, yet rates of new infections in the placebo group were similar.
"Past infection with early variants of the virus in South Africa does not protect" against infection with the new one, Mr Madhi said.
"There doesn't seem to be any protection derived."
Novavax said they are starting to develop a version of the vaccine that could more specifically target the mutations found in South Africa, in case health authorities eventually decide that updated dosing is needed.
A health worker stands behind a clear screen wearing PPE as she uses a long white swab to take a nasal sample from a man
So far, about 90 per cent of the COVID-19 illnesses found in the South African study appear to be the new mutant strain.(AP: Nardus Engelbrecht)
Novavax expected to arrive in Australia mid-year
Novavax expects to deliver the initial doses to Australia by mid-2021, and it will be predominantly manufactured in Europe.
A representative of the company told the ABC they were unsure of when results of the full phase 3 trials would be released as it would depend on when the data became available.
"[The results are] driven by a number of factors including the COVID-19 prevalence in the region, epidemiology, vaccine efficacy," they said.
Vaccines against COVID-19 train the body to recognise the new coronavirus, mostly the spike protein that coats it.
But the Novavax candidate is made differently than the first shots being used.
Called a recombinant protein vaccine, the US company uses genetic engineering to grow harmless copies of the coronavirus spike protein in insect cells.
Scientists extract and purify the protein and then mix in an immune-boosting chemical.
AP/ABC