Two new strains of COVID-19 are in the community and more transmissible than previous ones. Don’t put that mask away just yet.
In recent months, many of us have been complacent. A wave of COVID-19 peaked in January and while it certainly hasn’t gone away, it wasn’t spreading around the community at a rate of concern. But that is set to change as Omicron variants BA.4 and BA.5 have become the new dominant strains in Australia. The bad news, is they are more contagious than earlier variants of Omicron.
It is expected this current wave of COVID-19 cases will peak in mid-August. Federal Minister for Health and Aged Care Mark Butler this week predicted “there are going to be millions of people infected by COVID in this coming few weeks’ period”.
One major concern is that the health system will have difficulty keeping pace with infections. Queensland is expected to need far more than 1,000 beds just for COVID-19 at the peak of this wave. This has flow-on effects that will impact other medical services. Non-urgent elective surgery procedures are being cancelled or postponed.
Also alarming is the impact of this current COVID-19 wave on aged care facilities. There are more than 700 current outbreaks recorded in aged care facilities across Australia, with nearly 100 residents dying from COVID-19 each week. Staff shortages are also a problem – it is estimated that up to 20% of aged care staff are off sick every day due to COVID-19, the flu, and other winter colds.
National Seniors Australia Chief Advocate Ian Henschke believes it is important that the community doesn’t make the problem worse by bringing illness into aged care homes as visitors. He explained: “Make sure that you are up to date with your own vaccinations and that you have had your flu shot as well. I would urge people to make sure that they are not unintentionally spreading the virus into an aged care home. It is important that visitors follow aged care facility rules, even if they are not mandated by state governments.”
What is the threat of BA.4 and BA.5?
Quite simply, BA.4 and BA.5 are more contagious, and both strains are more resistant to vaccines and natural immunity.
To give some context around how transmissible BA.4 and BA.5 is, consider the R0 score given to the variants. This score is the average number of people a single case infects in a population with no immunity.
The original Wuhan strain of COVID-19 had an R0 of 3.3, Delta had an R0 of 5.1, and Omicron had an R0 of 9.5.
BA.4 and BA.5 have an R0 of 18.6. This R0 score is similar to measles, which is considered to be the most infectious viral disease.
This week, NSW Health has advised that, because the two new strains are so resistant, the COVID-19 reinfection period has been reduced from 12 weeks to just four weeks. Previously, the position of NSW Health was that the risk of COVID transmission from a person who had been infected with COVID-19 was low for the first three months after they left isolation.
NSW Chief Health Officer Dr Kerry Chant: “They are more able to evade immunity gained from previous infection and vaccination reinfection is more likely and possible just weeks after a prior infection.
“We’re urging people who have recently had COVID-19, even if they left isolation in the past four weeks, not to be complacent. If you develop symptoms again, make sure to test and isolate.”
Because BA.4 and BA.5 are so transmissible, Australia is currently seeing an exponential growth in case numbers.
It is expected this current wave of COVID-19 cases will peak in mid-August.
How to stay safe
The Australian Technical Advisory Group on Immunisation (ATAGI) recommends people aged 50-64 years get a fourth COVID-19 vaccination (their second booster). While it isn’t a recommendation, ATAGI have given permission for people aged 30-49 to also get the fourth vaccination. David Montefiori, a professor at the Human Vaccine Institute at Duke University Medical Centre, told 7 News: “If your last boost was over six months ago, you might want to consider getting boosted again now with the current vaccine to keep your protection strong while we’re still getting through this pandemic.”
Experts recommend that people once again wear masks in indoor venues, with most suggesting that N95 or P2 masks are the only masks that can prevent transmission of Omicron.
Jeremy Howard, a data scientist with the University of Queensland, conducted the world’s largest review on the ability for face masks to stop aerosol spread of COVID-19 in 2020. He told the ABC: “My guess is that the current mask mandates in Australia actually do nothing at all because they don’t mandate masks that work against Omicron.
Ditch your cloth masks and also ditch your surgical masks. Those are those blue and white masks that many of us use. They have big holes in the sides. Omicron is so aerosolised, so it’s such tiny particles that float in the air.”
“When you breathe in, you’re sucking in those respiratory particles.”
Mr Howard advises that it is not true that an N95 or P2 mask can be worn only once. He says that they can be worn until the strap wears out. For those over the age of 70 who test positive for COVID-19, there is some good news with improvements to access antiviral treatments. The government has just placed the antivirals on the Pharmaceutical Benefits Scheme (PBS). These antiviral treatments have helped keep people out of the hospital, easing pressure on the health care system. More than 73,000 Australians have benefitted from using the treatments.
Better vaccines
The good news is better vaccines are on the way. Unfortunately, they won’t be available before this current wave of infections peaks. Two vaccines that specifically target the Omicron variant have been granted “provisional determination” by the Therapeutic Goods Administration in Australia. Drug manufacturer Pfizer must now submit further data to the TGA from human trials about how the treatment works and its safety. Not known yet is how effective the vaccines might be against the BA.4 and BA.5 subvariants.
