According to a new study published in the journal Lancet Infectious Diseases, individuals who have had coronavirus may experience severe symptoms of the virus during its reinfection.
The study was carried out after a Covid-19-positive patient, who had no co-morbidities or immune disorders and recovered from the virus. However, he ended up on ventilation when the virus resurfaced.
The 25-year old male was infected with two distinct SARS-CoV-2 variants within a 48-day time frame while testing negative in between infections.
The study observed that the patient’s second infection was more severe, resulting in hospitalisation with oxygen support, indicating previous exposure to Covid-19 may not translate to guaranteed total immunity.
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The patient tested negative for the virus after testing positive for SARS-CoV-2 in April 2020, the researchers said.
In June, after experiencing severe Covid-19 symptoms, including fever, headache, dizziness, cough, nausea, and diarrhoea, the patient was hospitalised and tested positive for the second time.
The patient has since been discharged from the hospital and has recovered from the second infection as well, the study noted.
The researchers asked people to be cautious and take all necessary precautions even if they had recovered from the virus.
Lead author Mark Pandori from the University of Nevada said in an official statement: “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.”
“It is important to note this is a singular finding and does not provide generalisability of this phenomenon,” Pandori said.
According to the scientists, at least four other reinfection cases have been confirmed globally — in Belgium, the Netherlands, Hong Kong, and Ecuador.
“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,” Pandori added.
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“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,” he further stated.
The researchers speculated that the patient who had suffered from the severe symptoms of the virus may have contracted the mutated and virulent version of the virus the second time.
The researchers also believe there is a possibility that many similar cases among individuals may be asymptomatic, and therefore likely to remain undetected under current testing and monitoring practices.