‘What the hell?’: the unlucky Australians who have caught Covid twice

When Peter Coleman took a rapid antigen test just weeks after recovering from Covid-19, it was partially "for the fun of it".

Peter and his husband first tested positive to the virus on 10 January, during the post-holiday period that saw a spike in cases hit Melbourne and much of Australia.

"I was feeling really unwell but I didn't expect to be positive, I thought I'd just double check," he says.

Peter is one of the unlucky Australians to have been reinfected with Covid-19 after making a full or partial recovery from the virus.

No data on Covid-19 reinfections is currently being collated by the federal government. But a spokesperson from the Department of Health says the emergence of Omicron has seen a "significant increase" in the risk of reinfection compared with previous variants.

"There is increasing evidence that there is little cross-neutralisation with Omicron," the spokesperson says.

"Whether Omicron infection protects against another Omicron infection is unclear and there remains significant uncertainty about the durability of immunity following infection with the emergence of Omicron."

When Peter first acquired the virus, he was hit by brain fog so bad he forgot how to order food on Uber Eats, along with muscle aches and fatigue. The second time, though, symptoms were very different - more akin to a common cold or flu.

Peter, who works from home, says he had "no idea" where he acquired the second infection, only that it happened just outside the 30-day period when he initially tested positive.

Fully vaccinated, Peter expects he had been hit by the Omicron strain, but has no way to know for sure.

Peter says the second bout was relatively minor. When a nurse rang to check on him, she asked if he was feeling depressed.

The Communicable Disease Network Australia "continues to monitor the evidence on reinfection and whether the definition of reinfection in the national public health guidelines requires review".

If someone is re-exposed to the virus in the 28 days after being released from isolation, they're exempt from further quarantine - a decision last reviewed on 2 February.

A senior research fellow at the Kirby Institute's infection analytics program, Dr Deborah Cromer, says the likelihood of acquiring a Covid-19 infection twice is partially dependent on the variant and time since vaccination.

While two doses of the vaccine provides protection against symptomatic disease upwards of 80% or 90% with Delta, with Omicron it drops to about 70% for mRNA vaccinations and 40-50% for AstraZeneca.

Once receiving a booster, though, protection increases to 70-80%.

"Very early on when the original strain was circulating, we were asking how much protection someone who has the disease had from getting the disease again," Deborah says.

"The trials show people who've had the Pfizer vaccine primary dose have twice as much [immunity] as someone who's recovered from normal virus. But all vaccines are primarily giving you immunity targeted against the original strain."

Deborah says once someone has acquired the virus, they have specific immunity against that variant, as well as some general immunity against SARS-Cov-2.

"You're less likely to get the same variant again, but you're certainly not completely protected," she says. "Nevertheless, we would expect it to be less severe. Protection will grow, like what we see with the flu now."

While Covid-19 has some key differences from the flu, Deborah says similarities exist, as it is possible to have both viruses without symptoms or with mild symptoms, and repeated exposure encourages the body to have good immunity.

"That's probably where [Covid-19] will eventually go," Deborah says.

"Each time you experience a SARS-Cov-2 infection, your immunity will be boosted somewhat, which would mean the next time you'll still have some immunity remaining."

Clancy Read first tested positive to the virus during Fiji's second wave in August of last year. Living in Suva, her and her family had lived a relatively Covid-free life until "shit hit the fan" in April.

"We were a close contact, and all went and got tested. My daughter, who was two at the time, was the only one who came back positive," she says.

"It was in the chest, in my breathing, I'd be laying there in the middle of the night thinking 'Oh God, at what point do you say I need to call it and seek medical attention?'"

Clancy thinks that if she had been in Australia, she would have admitted herself to hospital - but feared being split from her husband and daughter and getting sicker alone.

"The hardest part was not knowing how bad it was going to get," she says. "The psychological symptoms were just as bad to the physical ones."

Then, after months of slow recovery, the Christmas period arrived and Clancy tested positive again.

Deborah says that as the pandemic continued, it wouldn't be "particularly unlikely" to be reinfected with the virus.

"We've had a relatively small time window for people to have repeated infections in Australia. It might be unlikely [now] because of that," she says. "But from a theoretical point of view, having Covid is not special - you get some level of immunity from having had the disease and some from vaccination. Both will boost your immunity."

Eleanor is still suffering from her exposure to the virus. She first tested positive to Covid at the start of January during the Omicron wave, after her housemate contracted the virus.

Eleanor, who did not want to use her surname, had a range of symptoms - headaches, diarrhea, shortness of breath, insomnia - which began to subside within a few days. But then her second housemate returned from work out of town weeks later, and tested positive upon his arrival. This time she had different symptoms.

"Fever, chills, cough, swollen glands."

Eleanor is normally an active person - she does rock climbing as well as regular workouts with a personal trainer.

"I get frustrated by people saying it's a minor cold or flu. I'm a healthy 33-year-old and I've had shortness of breath for over a month now. Getting Covid twice is more than enough."