Coronavirus: Being infected once may not make stop you getting it again

Contracting COVID-19 once may not make you immune from it in the future, a health expert warns.

It's widely assumed there is no threat of contracting coronavirus a second time, because your body produces antibodies to fight off the infection and give you natural immunity.

While this appears to be true in most cases, news reports in China and Japan appear to show this is not always the case.

Writing for Forbes, Bruce Lee, Professor of Health Policy and Management at the City University of New York, notes that there are at least three cases of people contracting the disease twice in quick succession.

Last month, Reuters reported that a Japanese tour bus guide had tested positive just weeks after recovering from the illness for the first time. Similarly, a Tokyo man in his 70s fell ill with COVID-19 less than a fortnight after contracting it on a cruise ship and recovering fully.

Perhaps most notably, Beijing media outlet Caixin reported that 14 percent of COVID-19 patients had tested positive again after being discharged from hospital.

While no medical studies have been carried out on whether it is possible to get this strain of coronavirus more than once, Prof Lee suggests the multiple news reports are cause for concern.

Has the UK got its COVID-19 action plan all wrong?

If it is possible to contract coronavirus more than once, then the UK may have to rethink its current strategy to combat COVID-19.

On Sunday (NZ time), the UK announced a plan to let the deadly coronavirus spread through the population in an attempt to force a form of herd immunity.

UK Prime Minister Boris Johnson is in support of allowing COVID-19 to spread through the population.
UK Prime Minister Boris Johnson is in support of allowing COVID-19 to spread through the population. Photo credit: Getty

Most other countries, including New Zealand, are implementing strict measures to either keep the virus out or slow its spread as much as possible.

This is a technique called 'flattening the curve', which aims to keep the number of sick people at any one time below the maximum capacity of the health system.

But the UK is trying something different.

"Our aim is to try and reduce the peak, broaden the peak, not suppress it completely," said British chief scientific adviser Sir Patrick Vallance.

"Also, because the vast majority of people get a mild illness, to build up some kind of herd immunity so more people are immune to this disease and we reduce the transmission, at the same time we protect those who are most vulnerable to it."

However, the goal of herd immunity may be unattainable if it comes to light that people are able to fall ill more than once.