What we know about the virus variant from India that’s spreading in Victoria
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The coronavirus variant first spotted in India that has so far infected 15 people across Melbourne is probably as contagious as, or slightly less contagious than, the fast-spreading British version of the virus.
The variant now spreading in Victoria was first identified in India in October as the country experienced a surge in infections.
Tuka Tahir prepares a jab at the Melbourne Showgrounds vaccine hub on Wednesday.Credit:Eddie Jim
It remains unclear how effectively antibodies from the Pfizer and AstraZeneca vaccines will neutralise the variant, known as B.1.617.1, as the studies are yet to be done.
However, in a hopeful sign, both vaccines are effective against a closely related variant.
“[Lab dish] evidence does suggest that there is a small reduction in neutralisation by antibodies generated by the AstraZeneca or Pfizer vaccines when compared to earlier variants,” said Dr Megan Steain, a virus researcher at the University of Sydney.
“However, this is unlikely to have a major impact on the efficacy of these vaccines.”
COVID-19 mutates all the time – the “original” version from Wuhan is almost never seen now – but B.1.617.1 caught scientists’ eyes because it carries a collection of mutations thought to increase infectiousness and antibody evasion.
Virus mutation is a natural and expected process, caused by random changes – errors – made to genetic code as the virus copies itself. Every time a person is infected, there is a chance of a random error; the more cases, the more variants are likely to arise.
India’s enormous and unchecked outbreak has become a variant factory: two cousins of this variant have now also been identified, each with slightly different mutations, all slightly more contagious than the original virus that emerged in Wuhan.
“That’s generally the direction all evolution takes,” said Dr Norelle Sherry, a medical microbiologist at the Doherty Institute.
People wait for a jab at the Melbourne Showgrounds vaccination hub on Wednesday.Credit:Eddie Jim
“But the key here is a virus must replicate to mutate. If we are able to extinguish the virus by strong public health interventions and vaccinations, it won’t have the opportunity to keep mutating and developing these other variants.”
Evidence from experiments on animals suggests B.1.617.1 generates higher viral loads than older versions of the virus; if replicated in humans, that would make it more easily transmissible.
Studies on B.1.617.1’s ability to evade antibodies have generated conflicting results, with some finding limited effect and others noting large drops in the ability of vaccines to neutralise the virus. However, there remains no high-quality human-level evidence of whether B.1.617.1 can evade antibodies generated by vaccines.
The variant lab at the Kirby Institute – seen here through thick protective glass.Credit:James Brickwood
Associate Professor Stuart Turville is studying the effect of antibodies generated by Pfizer and AstraZeneca’s vaccines against the variant at his lab at the Kirby Institute.
So far, B.1.617.1 appears to be more evasive than its cousin B.1.617.2, he says.
Vaccines from Pfizer and AstraZeneca both exhibit a drop in effectiveness – Pfizer’s falling to 88 per cent, AstraZeneca’s to 60 per cent – against B.1.617.2, according to a British study.
It remains unclear if that data has any relevance to B.1.617.1.
“We don’t know if it will be the same,” said Professor Fiona Russell, a vaccine expert at the Murdoch Children’s Research Institute and an adviser to the WHO.
The British study could not calculate how effective the vaccines are against serious illness and death, but scientists expect them to be highly effective.
“The overall message is any vaccine is far better than no vaccine,” said Dr Sherry.
“The vaccines we’re using in Australia are likely to be quite effective against symptomatic and severe disease – and we’d strongly encourage everyone who can be vaccinated to be vaccinated as soon as they can.”
Science and health explained and analysed with a rigorous focus on the evidence. Examine is a free weekly newsletter by science reporter Liam Mannix. Sign up to The Age’s here and the Sydney Morning Herald’s here.
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