Early research suggests that you are more likely to have serious health problems if you contract COVID-19 more than once.
Table of Contents
Core items:
- COVID-19 infections are on the rise again thanks to the latest Omicron BA.4 and BA.5 subvariants
- A study that has yet to be peer-reviewed shows that reinfection is likely to be more serious
- COVID-19 is expected to be a leading killer of Australians this year
Reinfections of the virus are increasing in Australia after growing two subvariants of Omicron, BA.4 and BA.5, which are expected to soon become the most dominant COVID-19 strains.
There was hope that the health risks associated with contracting COVID-19 would decrease in subsequent infections.
However, Nancy Baxter of Melbourne University’s School of Population and Global Health said early research based on data from the US Department of Veterans Affairs database showed that was not the case.
The research, which has yet to be peer-reviewed, shows that while immunity from contracting the virus has some benefits, the likelihood of negative health effects increases with each successive infection.
“You remain at risk for things like breathing problems, shortness of breath, heart problems, long COVID and … a higher than expected risk of death,” Professor Baxter said.
“That means the more often you get it, the more likely it is that you’ll eventually experience a really negative consequence of COVID-19.”
In addition, the immunity benefits of contracting the virus wear off over time, making reinfection more likely.
“For the first month and probably up to the first few months after you get Omicron, you have some protection against it, but then it wears off quickly,” Professor Baxter said.
Although the study included more than 5.5 million people, only 10 percent (566,020) were women, which may result in an inaccurate representation in a more balanced population.
dr Deepti Gurdarasani of Queen Mary University of London agreed that while the research has some caveats, its findings have significant implications for the way we think about COVID-19 reinfections.
“It’s clear that the ‘reinfection is benign’ or ‘mild’ narrative doesn’t really apply,” she said on Twitter.
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Gap in Australian data
In Victoria, more than 20,000 reinfections have been recorded through data matching procedures.
There are more than 11,300 in New South Wales, almost half of them after the Omicron variant surfaced last November.
But Professor Baxter said those numbers were a gross underestimate.
“The numbers we have aren’t great because reinfection doesn’t record well, especially because they don’t now allow you to record a second infection with COVID-19 if you’ve had it within four months.”
COVID-19 infections reported below
The official number of daily COVID-19 infections is around 30,000, well below the early 2022 peak of over 100,000.
But Professor Baxter warned that the official numbers are also a gross underestimate.
“We don’t think they will be recorded with the same accuracy as in the past,” she said.
“We know that PCR tests are harder to come by, … not everyone records their rapid antigen tests and not everyone even runs COVID-19 tests.”
As mask-wearing declines and community immunity ebbs since the January peak, Professor Baxter expects infections and deaths to continue to rise.
“We had a period of about six weeks where the numbers started to go down. Now we’re seeing a reversal of that trend, with the numbers rising again,” she said.
Professor Baxter agreed with other epidemiologists who called for a greater focus on mask wearing and air filtration to reduce transmission.
“Just as we have the right to expect clean water in our workplaces, we should also have the right to expect clean, safe air in our workplaces,” she said.
On Thursday, the federal government launched an $11 million publicity campaign to encourage people to get their third booster shot, a goal Professor Baxter said is critical to reducing transmission and deaths.
“People need to be aware of the importance of this booster and make sure we encourage it and get everyone to have this booster.
“That will make a big difference.”
More than 9,500 people have died from COVID-19 in Australia so far, most of them this year.
On average, more than 50 people are now dying from the virus every day, and Professor Baxter expects case numbers and deaths to remain at high levels for some time to come.
“COVID-19 will be one of the leading killers of Australians this year and it doesn’t seem to be slowing down at all,” Professor Baxter said.
“I know everyone wants to move on from the pandemic, but COVID-19 just doesn’t have a memo.”