A PATIENT is the first in the world to be reinfected with coronavirus – just four months after recovering from the bug, scientists claim.
The 33-year-old IT worker was infected by two “completely different” strains of Covid-19, according to researchers in Hong Kong.
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He was in good health before developing a cough, headache and fever with the first infection and tested positive for Covid with swab test on March 26.
The patient, who lives in Hong Kong, was hospitalised but recovered and discharged after having two negative tests on April 14.
He tested positive again during screening at Hong Kong airport on August 15 when returning from Spain, via the UK.
The man was again hospitalised but had no symptoms, which suggests that subsequent infections may be milder, the researchers said.
Genomic sequencing identified differences in the viruses, proving two separate infections, rather than a relapse.
Previous reports have been anecdotal, with no genetic evidence.
The revelation by Hong Kong researchers is a major blow to scientists who hoped survivors would develop long-term immunity.
Experts warn it suggests the virus could scupper vaccines and persist in the population like the common cold.
Study leader Dr Kelvin Kai-Wang To said the case shows the importance of everybody observing social distancing.
He added: “This case illustrates that re-infection can occur just after a few months of recovery from the first infection.
“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.
It is unlikely that herd immunity can eliminate SARS-CoV-2, although it is possible that subsequent infections may be milder than the first
“Since the immunity can be short lasting after natural infection, vaccination should also be considered for those with one episode of infection.
“Patients with previous Covid-19 infection should also comply with epidemiological control measures such as universal masking and social distancing.”
He continued: “It is unlikely that herd immunity can eliminate SARS-CoV-2, although it is possible that subsequent infections may be milder than the first infection, as for this patient.”
Commenting on the report, Dr David Strain, from the University of Exeter, said: “This is a worrying finding for several reasons.
“The first is that it suggests that previous infection is not protective.
“The second is that it raises the possibility that vaccinations may not provide the hope that we have been waiting for.
“Vaccinations work by simulating infection to the body, thereby allowing the body to develop antibodies.
“If antibodies don’t provide lasting protection, we will need to revert to a strategy of viral near-elimination in order to return to a more normal life.”
But Prof Brendan Wren, from the London School of Hygiene & Tropical Medicine, said the hunt for a vaccine should continue.
He added: “With over 3million cases of Covid-19 worldwide, the first reported case of a potential re-infection with SARS-CoV-2 needs to be taken into context.
“It appears that the young and healthy adult has been re-infected with a slight SARS-CoV-2 variant from the initial infection three months previously.
“It is to be expected that the virus will naturally mutate over time.
“This is a very rare example of re-infection and it should not negate the global drive to develop Covid-19 vaccines.”
Dr Jeffrey Barrett, from the Wellcome Sanger Institute, said: “It is very hard to make any strong inference from a single observation.
“Given the number of global infections to date, seeing one case of reinfection is not that surprising even if it is a very rare occurrence.
“I think their ‘implications’ are far too broad given that they have seen just one instance.
“This may be very rare, and it may be that second infections, when they do occur, are not serious, though we don’t know whether this person was infectious during their second episode.”
The findings have been accepted for publication in the journal Clinical Infectious Diseases.