Otago University epidemiologist Michael Baker says Kiwis shouldn't be overly concerned about the 'first' proven case of COVID-19 reinfection.
Scientists reported a healthy man in Hong Kong was found to have contracted the virus on Tuesday, four-and-a-half months after his first bout of coronavirus.
It's the first 'proven' case in the world, with genome sequencing finding the two infections were clearly different.
But Professor Michael Baker says Kiwis shouldn't be overly concerned.
"This just might tell us that some people who get natural infection don't mount an immune response that is strong enough to protect them shortly afterwards from re-exposure, but that actually is the same for all infectious diseases," he said.
Those who get COVID-19 develop natural immunity. But it is not yet clear how strong it is, how long it lasts, and whether it's effective on different strains.
Malaghan Institute Director Graham Le Gros is currently working on a vaccine in New Zealand and said they are probably the better option.
"It probably means that vaccines are the way to go rather than letting herd immunity and natural infection make a population protected from the virus, there's too much variation, so let's make a good vaccine that does the job," said Professor Le Gros.
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In a lab in Portsmouth, English scientists are working on one of the frontrunners, the Oxford vaccine.
But if it works, they'll need to create billions of doses, fast.
"That process would generally be measured in years, and five years is not unusual," said Pall Biotech's Dr Clive Glover.
"We were able to design the process, get the equipment into one of our manufacturing partners and run the initial process within eight weeks. So it was a sprint to say the least."
US President Donald Trump is reportedly trying to rush through the Oxford vaccine before the US election.
But it will be at least the end of the year before there's a proven vaccine available, and even then it may not be a one-shot wonder.
"It's more likely that we'll need to have a booster shot every few years to keep the coronavirus at bay," says Professor Le Gros. "We're on the hunt, like everyone else, let's just wish us all luck."
Because what seems clear is that we'll have to live with this virus long term.
