Evidence of a SARS-CoV-2 strain was recently detected in Melbourne wastewater, leading to the detection of 26 locally acquired cases of COVID-19. Victorian Chief Health Officer Brett Sutton has confirmed that the strain is the B1.617 variant first detected in India.
The strain was genetically linked to the man who contracted the virus while in Adelaide hotel quarantine.
What is the B1.617 variant?
SARS-CoV-2 is the specific species of the virus that causes COVID-19. Just like in people and animals, one species can have different genetics – in the case of viruses, we call these strains or variants.
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The B1.617 variant was first detected in India in October 2020. It is called a “double mutant” because only two of its mutations are of particular note; they occur in the 452nd and 484th position of the genetic code, and both are parts of the spike proteins that help the virus break into our cells.
These individual mutations were both found in other variants, the former in the US and the latter in the UK and South Africa, but this particular variant cropping up in India and Melbourne contains both mutations together.
However, the different subtypes of the strain may present differently.
“It would be important to know if it is B1.617.1 or B1.617.2,” says Raina MacIntyre, Head of the Biosecurity Program at the Kirby Institute at the University of NSW.
“Earlier media reports indicated the person from Wollert was infected with B1.617.1. Based on reports from India, this variant may have atypical clinical presentations, such as abdominal pain, nausea, vomiting, diarrhea and hearing impairments, as well as an absence of fever.
“If this is the case, people should be on the alert for any of these symptoms as well as more typical COVID symptoms such as cough and fever.”
It is still unclear how quickly this particular variant spreads, but because of the rise in cases in India and the UK, it is possible that it is up to 50% more transmissible – that is, it may spread more easily.
“This reinforces several things we already know about this virus,” says Gerry Fitzgerald, a public health expert from Queensland University of Technology, who lists:
1. It is highly infectious amongst adults.
2. Due to our success with public health protections, our population remains very vulnerable.
3. Until we reach herd immunity in Australia, we will remain vulnerable and at risk from re-entry of the virus into the country through returning travellers. If this disease breaks out as it did in the US and throughout Europe, then we can expect more than 50,000 people to die.
4. Our only safe hope to obtain herd immunity is through vaccination.
5. While there are some rare side effects to the current vaccines, the risk of the diseases far outweighs the risks of the vaccine.
What should I do and can the vaccine help?
Victorians are encouraged to check their vaccine eligibility, continue to be tested and keep an eye on areas of concern.
“Vaccines will still be effective against the B1.617 variant,” says Rob Grenfell, CSIRO’s Health & Biosecurity Director. “A recent study from Public Health England shows that two doses of the vaccines are highly effective.”
Specifically, MacIntyre explains: “Reports from the UK also show that the effectiveness of one dose of Pfizer or AstraZeneca is only 33 per cent against B1.617.2; but this rises to 88 per cent after two doses for Pfizer and 59.8 per cent after two doses of AstraZeneca. This means it does have some resistance to vaccines, although not as much as the South African variant.”
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Other things to continue practising include handwashing, venue check-ins and mask-wearing.
“This is a timely reminder that we need to keep doing the basics until we get the population vaccinated,” says Hassan Vally, an epidemiologist at La Trobe University.
“Get tested if you have any cold-like symptoms, check in to venues using QR codes, wear masks where appropriate and disinfect your hands regularly. Whether we keep up with these precautions could be the difference between avoiding another lockdown or not.”