Hospital Dr News

Covid-19 reinfection in the US suggests exposure to virus doesn’t give total immunity

A 25-year old male in the US has been infected with two distinct SARS-CoV-2 variants within a 48-day timeframe, while testing negative in between infections.

The patient’s second infection was more severe, resulting in hospitalization with oxygen support, indicating previous exposure to Covid-19 may not translate to total immunity.

The researchers note that all individuals—whether previously diagnosed or not—should take identical precautions to prevent infection with SARS-CoV-2.

The case study, published in The Lancet Infectious Diseases, says the genomes of the patient’s virus samples were sequenced in April and June, displaying significant genetic differences between the two cases.

This implies the patient was infected twice by two distinct SARS-CoV-2 infections.

Mark Pandori of the Nevada State Public Health Laboratory said: “There are still many unknowns about SARS-CoV-2 infections and the immune system’s response, but our findings signal that a previous SARS-CoV-2 infection may not necessarily protect against future infection.”

He added: “It also strongly suggests that individuals who have tested positive for SARS-CoV-2 should continue to take serious precautions when it comes to the virus, including social distancing, wearing face masks, and handwashing.”

At least four other reinfection cases have been confirmed globally in Belgium, the Netherlands, Hong Kong, and Ecuador. However, only the Ecuador reinfection case displayed worse disease outcomes than the first infection.

Immunity doubts

Pandori said: “We need more research to understand how long immunity may last for people exposed to SARS-CoV-2 and why some of these second infections, while rare, are presenting as more severe.

“So far, we’ve only seen a handful of reinfection cases, but that doesn’t mean there aren’t more, especially as many cases of COVID-19 are asymptomatic. Right now, we can only speculate about the cause of reinfection.”

The authors present several hypotheses to potentially explain the severity of the second infection, including the possibility the patient subsequently encountered a very high dose of the virus which caused a more acute reaction the second time.

Bookmark and Share

Post a Comment

Enter this security code

Submit Comment for Moderation