A study released by The Lancet confirms the first case of reinfection by COVID-19 detected in a patient from the United States, suggesting that exposure to the virus does not necessarily translate into full immunity. Worldwide, it is the fifth confirmed episode of reinfection, according to that publication.
Verified by genetic sequence, a Nevada patient tested positive for two SARS-CoV-2 infections within 48 days, which confirmed, according to the aforementioned study, that a second infection can occur in a short time frame and that it can be more serious than the first.
The revealed findings also suggest that exposure to COVID-19 may not translate into a full guarantee of immunity although in relation to this point, the study warns that it is still necessary to investigate more cases of reinfection.
In that episode of reinfection by coronavirus -the first identified in that country-, the experts found evidence of an individual, without immune disorders known or underlying medical problems, infected with SARS-Co-2 on two separate occasions.
The reinfected patient
The 25-year-old Washoe County, Nevada, patient was infected with two variants of COVID-19 in a 48 day period and it was negative between both incidents. The second infection was more serious than the first and the patient had to be hospitalized and required oxygen treatment.
The study authors warn that regardless of whether or not a person has been previously diagnosed with COVID-19, identical ones should be adopted precautions to avoid contagion.
According to The Lancet, after testing positive for coronavirus last April, the aforementioned patient tested negative on two different occasions, but in June after experiencing severe symptoms associated with the virus such as fever, headache, dizziness, cough, nausea and diarrhea, he was hospitalized and tested positive a second time. Since then, he has already been discharged and has recovered from that second infection.
“There are still many unknown factors about SARS-CoV-2 infections and the response of the immune system, but our findings indicate that a previous SARS-CoV-2 infection may not necessarily protect against a future infection,” notes the lead author. of the study, Mark Pandori, of the Nevada State Public Sanitation Laboratory -located at the University of Nevada (USA) – and the Reno School of Medicine.
The expert considers that “it is important to bear in mind that this is a singular finding and does not provide a generalization of this phenomenon.” “While more research, the possibility of reinfections could have significant implications for our understanding of COVID-19 immunity, especially in the absence of an effective vaccine, “he observes.
Pandori adds that “individuals who have tested positive for SARS-CoV-2 should continue to take serious precautions when it comes to the virus, such as keep social distance, wear masks and wash your hands. “
The study shows that genomes of virus samples of that patient were sequenced in April and June, showing significant genetic differences between both cases, which implies that the patient was infected twice with SARS-CoV-2.
At least others have been detected four cases of reinfection of the virus globally in Belgium, the Netherlands, Hong-Kong and Ecuador, although only in the case detected in the latter country was the second reinfection episode worse than the first.
The authors present several hypotheses to explain the greater severity of the second episode of reinfection, including that the patient had been exposed the second time to a large viral dose that would have caused a more acute reaction or that he had encountered a more virulent version of the virus.
But the small possibility of a continuous infection that would imply some way that the virus would have been “reactivated”.