New and more dangerous varieties of COVID-19 from Britain and South Africa will be covered by the Pfizer and Moderna vaccines, preliminary evidence suggests, although the vaccines will be slightly less effective.
“We are yet to see a virus that can evade a vaccine response to a degree where it would be of significant concern,” said Associate Professor Stuart Turville, a virologist at the Kirby Institute.
An English patient receives a dose of the Pfizer vaccine inside Salisbury CathedralCredit:Getty
“The vaccine responses so far have been strong in many studies and this level of strength will hopefully translate to cover many different viral flavours.”
Pfizer’s vaccine won regulatory approval in Australia on Monday and the federal government plans to roll it out from the end of February.
The more contagious British variant of COVID-19 has been sequenced 50 times in Australia so far, and Brisbane was forced into a snap lockdown after a hotel quarantine cleaner in the city became infected with the strain.
Emerging evidence has suggested that the new variants slightly lower the effectiveness of both vaccine-induced and natural antibodies and British health authorities made headlines this week when they revealed concerns that existing vaccines might not work against the new variants.
A woman waits to be tested for COVID-19 in a shopping centre car park in Johannesburg.Credit:AP Photo/Jerome Delay
One study, posted on January 19 by a team led by scientists from the Rockefeller University in New York, looked at antibody responses to a virus bearing the variant’s mutations in 20 patients who had received either the Pfizer or Moderna vaccine.
It found vaccine-induced antibodies effectively neutralised viruses with the same mutations as B.1.1.7, the variant first spotted in Britain, and 501Y.V2, the variant first spotted in South Africa.
“The fact that neutralising activity is retained is encouraging,” said University of Sydney professor of medical microbiology James Triccas.
“Our focus should now be on next generation vaccines, in particular developing platforms that allow us to ‘pivot’ quickly to combat new variants.”
Vaccine researcher Professor James Triccas in a lab at Sydney University.Credit:Nick Moir
A second paper, led by the University of Cambridge’s Ravindra Gupta, looked at blood from 15 patients who had been given the Pfizer vaccine and also found modest reductions in vaccine effectiveness against a virus with B.1.1.7’s mutations.
“Vaccines will be impacted by variants,” Professor Gupta told The Age, “though not for most individuals or at population level unless more mutations accrue.”
And a third study, published by Moderna’s own scientists on Monday, found B.1.1.7 did not cut the vaccine’s power. The South African strain moderately reduced it, but the vaccine was still able to neutralise the virus. In a statement, the company said it would start developing a “booster shot” that could cover the new variant.
A vial of the Pfizer-BioNTech COVID-19 vaccine.Credit:Bloomberg
“This is not surprising and this is the normal behaviour of viruses, to mutate and escape,” said Victoria University immunologist Professor Vasso Apostolopoulos.
“For example, the flu vaccine is updated every year to include mutated variants of the virus.”
A fourth study looked at 501Y.V2, or B.1.351, as the variant first spotted in South Africa is also known.
That virus is raising the most concern among scientists because it includes nine changes to its spike protein. A variant spotted in Brazil bears similar changes.
In tests on the blood of 44 patients who had recovered from COVID-19, 21 had no detectable neutralising antibodies to 501Y.V2.
However, patients who had higher levels of natural immunity were much more likely to generate neutralising antibodies to 501Y.V2, suggesting a vaccine that produces a strong immune response might still cover the virus.
“The current vaccines are expected to still be effective but with time – hopefully years – we will likely need second generation vaccines that are more effective against new variants,” said Professor Brendan Crabb, director of the Burnet Institute.
Based on that, he said governments everywhere should be working to quickly vaccinate the population, alongside using standard control measures, such as testing and tracing, to push infection numbers down.
“Remember, the more virus there is, the faster variants will arise,” he said.
Science and health explained and analysed with a rigorous focus on the evidence. Examine is a weekly newsletter by science reporter Liam Mannix. Coming soon, sign up now.
Most Viewed in National
Source: Read Full Article