Just as Australians are getting prepared to roll up their sleeves for the COVID-19 jab, a new hurdle has emerged.
Variants of the deadly disease have already made their way to Australian shores, and experts say a lot remains unknown.
Two of the mutated strains, one from the UK (B117) and the other from South Africa (501Y.V2), have been detected in returned travellers in hotel quarantine.
Another mutation, known as P1, has also been identified in Brazil.
There’s no evidence any of these variants are deadlier than the original versions but they are more infectious and whether they will hinder vaccine effectiveness is yet to be determined.
NSW Health Minister Brad Hazzard last week boldly claimed the vaccines would work against all strains of the virus, but no one knows that for sure, according to The Westmead Institute’s Professor Tony Cunningham, a vaccine expert of 40 years.
Professor Cunningham explained some of the new strains were more transmissible due to the mutations that alter the coronavirus spike protein, the part of the virus that latches onto human cells, the same part vaccines target.
“People have obviously been concerned about whether one of the principal ways in which these vaccines work, and that is to produce an antibody that gets between the virus and the cell, is still going to work,” he told NCA NewsWire.
The Pfizer vaccine has been tested against a key mutation (N501Y), with scientists at University of Texas Medical Branch conducting the recent study using blood samples from people who had been given the vaccine.
“The protective antibody does seem to work against that 501 mutation in the test … that’s what a lot of other scientists are saying around the world, that there’s no evidence the emerging mutations are going to prevent the vaccines from working,” Professor Cunningham said.
If we did encounter mutations that were resistant to the vaccine, he said those behind the Pfizer jab believed they could easily build on the existing vaccination.
“The argument is the Pfizer people, or BNT (BioNTech), feel within six months they can come up with a new vaccine that would address that,” he said.
“This is very similar to what we’re doing with influenza every year.”
A lot remains unknown, though, since Australia’s other vaccine hopes – AstraZeneca-Oxford University and Novavax – are yet to be tested on the mutations.
The federal government has acquired 10 million doses of the Pfizer jab but more than 50 million of the AstraZeneca vaccine.
Professor Cunningham said he expected the scientists behind the latter to also conduct thorough testing on mutations.
“I am sure that’s going to happen. It’s already happened with Pfizer, I would be very surprised if the Oxford group are not doing this, but we just haven’t seen the results yet,” he said.
Infectious disease expert Marylouise McLaws said she was one of 13,000 scientists who attended a World Health Organisation meeting last week about mutations and vaccines.
She said mutations should not “theoretically” have a serious adverse effect on current vaccines.
“However, they reminded us that there it is too early to know, with any degree of certainty, the impact of circulating variants,” she told NCA NewsWire.
The department of health said COVID-19 had “not mutated enough to render current vaccines ineffective”.
Early research suggests that SARS-CoV-2 (the virus that causes COVID-19) has not mutated enough to render existing vaccines ineffective.
“The mutated strains of COVID-19 do result in changes in the virus’s spike protein, they are not considered enough to stop a vaccine being protective,” the department said in a statement.