While the COVID waves that have swept the country have reached just about everyone — or so it feels like — some of us are already on our second round of infection.
It is, however, a medical reality that speaks to the ever-changing nature of the SARS-CoV-2 virus and its ability to evade our immune systems — even when they’re supposed to be in tip-top condition.
Australia does not track or publicly release data on reinfections, so it’s hard to know exactly how many people have had COVID twice or more in the country.
Experts are worried, however, as case numbers remain high in Australia and the ‘natural’ immunity that would have been acquired during the Christmas period — when COVID infections skyrocketed — is likely starting to wane. This means that more people could start catching the virus for the second time soon.
How Can You Get COVID Twice?
It was generally assumed in the early days of the pandemic that catching COVID meant that you could then relax, as you were not going to get it again.
That may have been true with the original strain, but as the virus mutated and we saw variants like Delta and Omicron take over, it quickly became clear that those who had been infected previously were not immune to later strains.
This is because the genetic mutations in the newer strains make the virus appear different enough to our immune systems that they can’t be immediately recognised and dealt with before infection takes hold.
Overseas studies show that COVID re-infections are becoming more common, with the re-infection rate for Omicron making up 14% of new cases in the UK, a jump from just 1% of new cases prior to the arrival of that variant.
Epidemiologist and associate research fellow at the Burnet Institute, Mike Toole, has said that protection does appear to be waning as the virus changes:
“Qatar did a big survey, and found that during those original strain — Alpha, Beta, Delta, if you got infected, you were about 90% protected from other infection,” he said.
“Now it’s down to just over 50%.”
What Are The Chances of Catching COVID Twice?
It’s still unlikely to catch COVID twice — particularly if you’ve had COVID recently. However, as the virus grows and changes and our naturally acquired immunity from infection wanes, it will become increasingly likely, almost to the point of certainty, that everyone is going to get COVID many times over.
COVID is of course a coronavirus — the same virus that causes the common cold. Catching a cold once or twice a year wouldn’t be uncommon, as cold viruses also change and mutate, evading our immune systems, and we shouldn’t expect it will be much different with COVID.
The good news is that reinfections are likely to be milder than earlier infections. Immunity, vaccines, and the trend towards milder strains of the virus — like the recently detected BA.4 and BA.5 strains in Australia — suggest that it’s going to be much less severe the second or third time around.
As for how likely you are to be reinfected, well, that depends on a number of factors. Your potential exposure to the virus based on how often you mix with people in risky settings, your age, your immune status, and your vaccine status are all likely to play a factor. Some experts have said one in 20 or one in 30 new cases in Australia are reinfections, and that we shouldn’t expect to dodge it simply because we’ve had it before.
The head of Australia’s Therapeutic Goods Administration, Professor John Skerritt, has said that “COVID reinfections can and do occur”.
“If you’ve had Covid, don’t lull yourself into a false sense of security,” he said, adding that anyone who has yet to receive their booster should do so immediately.
Some unlucky Aussies have managed to catch COVID twice within a month, while the current holder of the dubious record of ‘fastest COVID reinfection’ appears to be a 31-year-old Spanish woman who caught COVID twice in 20 days.
COVID infection rates in Australia are currently some of the highest in the world based on the size of our population. This has partially been put down to the fact that we still have free — and relatively high — COVID testing available, as well as the idea that we’re simply done with living under restrictions. The virus, as always, has other plans.
Experts are warning that a rise in reinfections is currently underway as we enter winter and with that lessening immunity becoming a greater factor. Newly arrived variants are thought to be about 25% more infectious than Omicron which are also expected to spark a new rise in cases, particularly as we’re less protected against newer strains.
The best advice is to play it safe, remember there is still a pandemic happening, test often, mask up when necessary, and remember that having had COVID is no guarantee you won’t catch it again.