Unfortunately, the Omicron variants of SARS-CoV-2 is now circulating widely in Australia, so going to work, school or socialising also comes with significant risk of catching and spreading the virus.
There are hundreds of school outbreaks at the moment, with teacher shortages and many schools reverting to remote learning to manage the risk. Understanding the way SARS-COV-2 spreads is key to preventing transmission.
The virus spreads through the airborne route and is inhaled. SARS-COV-2 spreads via tiny aerosols that accumulate in the air, especially in poorly-ventilated indoor spaces, just like cigarette smoke does.
Aerosols are more concentrated the closer you are to someone’s mouth and nose, which is why even in outdoor environments there is benefit in maintaining some distance away from each other.
Australia has very high vaccination rates, with over 95% of people 16 years and over having had two doses, and about 85% of children 12-15 years.
Two-dose rates are lower in children 5-11 years, because of a delayed start to the program and spacing of the doses eight weeks apart.
This explains the epidemics in primary schools at the moment, and the number of people getting infected at home from their school aged children.
Unfortunately, vaccines alone are not enough. They certainly protect against getting severely ill or dying, but two doses wane and do not protect much at all against symptomatic infection with Omicron.
The Omicron variant evades the vaccine immunity much more than previous variants like Delta.
A third dose substantially improves protection, but our 3rd dose rates are not as high as they should be, at around 70%.
But even immunity from the 3rd dose wanes, and there is now a recommendation for a 4th dose for people 65 and over, Aboriginal and Torres Strait Islander people 50 and over and people with severe immunosuppression. But the bottom line is, we need a layered strategy that includes vaccines, masks and safe indoor air.
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If you are not already vaccinated, get vaccinated and get as many vaccine doses as you are eligible for, as soon as possible.
For all adults, being fully vaccinated means being triple-vaccinated. Get your boosters as soon as you are eligible. Pfizer and Moderna are similar vaccines and you should get whichever you can access earliest.
What you can do to minimise risks
You should also minimise contact with people who are not fully vaccinated and do not be afraid to ask if people are fully vaccinated and boosted.
While it may cause some social friction, spending less time with unvaccinated family members and friends will be safer for you and them, and it will help you protect infants and children who are not yet eligible for vaccination.
Approaching these conversations with empathy help unvaccinated friends to reconsider their decision.
Masks are also important, and now that they are not mandated, wearing a respirator (which is a well fitted type of mask with high filtration, like a N95 or P2 mask) is even more important.
Always wear high quality mask when in crowded indoor locations or when travelling. Minimise the risk of COVID-19 by avoiding large gatherings, shopping online and have gifts and groceries delivered.
Avoid spending time in busy indoor environments like pubs, where lots of people are unmasked and likely to be emitting virus-laden aerosols into the shared air.
Consider skipping some functions entirely, particularly if you live with or work with anyone at higher risk. If entertaining, use your alfresco or outdoor areas as much as possible and reduce numbers so it does not get too crowded.
Open as many doors and windows in your house or apartment as you can, keep your space well ventilated.
A portable air purifier with a HEPA filter can dramatically reduce risk, especially if you cannot open windows. See this guide by A/Prof Robyn Schofield and read OzSAGE’s ventilation advice for more details.
Testing is also important, if you have any symptoms or are a close contact. A rapid antigen test (RAT) can be bought online, or at the supermarket or pharmacy.
The day of social events, use a RAT and ask your party guests to get tested. If you can afford a pack of tests, you can test people at the door and get the results in 15 minutes.
You should also have a COVID-19 plan in case someone in the household becomes infected. Having a pulse oximeter is a good idea – of you get COVID, you can monitor your own oxygen levels.
Some smart watches can do this too. Work out who would care for others dependent on you, such as children or pets. Have a plan for isolation within the home – is there a separate bedroom and bathroom a sick person could use?
OzSAGE offers a range of practical advice to reduce spread of COVID, based a Vaccine-PLUS and Ventilation strategy. And remember, there are now good antivirals and other drugs that are available for some people, so check with your GP.
Professor Raina MacIntyre is Head Biosecurity Research Program Kirby InstituteUNSW Medicine and Professor of Global Biosecurity & NHMRC Principal Research Fellow Kirby Institute.
