The world’s first case of a person becoming reinfected with a second strain of coronavirus has been recorded by scientists in Hong Kong.
The patient, a 33 year old man, had first contracted coronavirus back in March, according to researchers at Hong Kong University’s department of microbiology.
He was hospitalised after showing the common symptoms, such as a cough and a fever, on 29 March, where he tested positive for the virus. He was eventually discharged on 14 April, after receiving two negative test results.
However, on 15 August, the same man flew to Hong Kong from Spain and upon a routine airport screening, was found to have the virus once more. He was hospitalised for a second time. However, during this period he showed no symptoms, according to the university researchers.
What is ‘natural immunity’?
Natural immunity is the body’s automatic, adaptive response to coming into contact with a disease. The immune system fights off an infection and becomes stronger, or sometimes fully immune, to further infections.
Some scientists initially proposed that natural immunity would protect people who had previously been infected with coronavirus from becoming reinfected.
However, researchers have raised concerns that this case of reinfection could have implications for the theories of natural immunity.
Vaccinations for those previously infected ‘recommended’
Writing in a medical paper, the researchers said the new case had revealed that natural immunity to the virus may only be “short lasting” and this may suggest artificial immunity through the use of a future vaccine could also be unable to give permanent protection.
They recommended use of future vaccination for those who have already had the virus, as well as those who have not.
In a statement, the university researchers said, “Our findings suggest that SARS-CoV-2 may persist in the global human population as is the case for other common-cold associated human coronaviruses, even if patients have acquired immunity via natural infection.
“Since the immunity can be short lasting after natural infection, vaccination should also be considered for those with one episode of infection.”
They also recommended that anyone who has had a previous Covid-19 infection to remain vigilant and adhere to “epidemiological control measures such as universal masking and social distancing.”
Can you catch the same strain of coronavirus twice?
There are known to be variants of coronavirus in circulation, with a mutation, called D614G, having become the dominant strain of the virus in recent months.
Brendan Wren, professor of microbial pathogenesis at the London School of Hygiene and Tropical Medicine, explained that the man in question had most likely been infected with another “variant” of Covid-19, rather than the one he contracted initially.
Wren added that it is “to be expected that the virus will naturally mutate over time.”
“This is a very rare example of reinfection and it should not negate the global drive to develop Covid-19 vaccines,” he said.