First COVID-19 Reinfection confirmed in Hong Kong

First COVID-19 Reinfection confirmed in Hong Kong

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A man in Hong Kong has been confirmed as the first case to become re-infected with COVID-19. The man previously had COVID-19.

Hong Kong researchers have sequenced the virus genomes from both of the man’s infections and found significant differences, implying the patient had been infected with two different types of strains. 



The patient mounted an immune response to the new infection but did not experience symptoms.

Dr Nikki Turner, Director, Immunisation Advisory Centre, University of Auckland, comments:

“This is a single case and is of scientific interest, but it is important not to assume at this point that rapid waning immunity is a frequent occurrence across populations.”

“For any infectious disease there is the potential to get it a second time, and this is more common for some infectious diseases than others. We know that repeat infections occur with other coronaviruses, influenza viruses and other common respiratory illnesses. The duration of immunity following the first infection varies both with the type of organism and the immune response from the person infected.”

“But there are also important factors relating to the individual exposed. For example, people who are on medications that may affect their immune response, or have certain medical conditions that affect their immune response, may have a shorter duration of protection than others.”

“When someone does get sick again from the same virus, it is usually milder as there is some existing immunity, but the immunity is not adequate to fully protect. I understand that is what was seen in this case.”

“There is still a lot unknown about the duration of immunity following infection with COVID-19, and over time more will become established about how long duration of immunity is expected to be.”

Prof Brendan Wren, Professor of Microbial Pathogenesis, London School of Hygiene & Tropical Medicine, said:

“With over 3 million 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.”

There are sparse papers published of patients that may have been re-infected. This is based on clinical features with or without supporting regular lab diagnostic testing, i.e. seeing a PCR POS-NEG-POS results pattern with similar clinical illness-recovery-illness/asymptomatic infection patterns. However, these other reported potential reinfection cases have not yet been proven by further sequencing.

Research credit to Science Media Centre.

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