A study published Tuesday showed that Covid-19 patients may face more severe symptoms the second time they are infected with the virus, thus confirming that it is possible to contract the emerging coronavirus more than once.
The study, published in The Lancet Infectious Diseases journal, documents the first confirmed case of the virus returning to people recovering from Covid-19 in the United States, the country most affected by the pandemic in the world, and indicates that infection with the virus may not guarantee future immunity.
The patient, a 25-year-old man from Nevada, contracted two different strains of SARS-Cove-2, the virus that causes Covid-19, within a 48-day period. The symptoms of the second infection were more severe than the first and forced the patient to receive hospital treatment and oxygen assistance.
An individual may be infected with COVID-19 more than once
The study indicated four other recovered cases of the virus that were confirmed worldwide, in Belgium, the Netherlands, Hong Kong, and Ecuador.
Experts said that the chances of the virus returning to recovery may have major repercussions on the efforts made by the world to combat the epidemic. It could particularly affect efforts to find a vaccine, one of the most important research goals of pharmaceutical companies.
“The potential for recurrence may have important implications for our understanding of immunity from Covid-19, especially in the absence of an effective vaccine,” said Mark Banduri of Nevada State Public Health Laboratories and the senior author of the study.
He added, “We need more research to find out the duration of immunity for people who have contracted SARS-Cove-2, and why some cases of the virus returning to recovering, although they are few, are more severe.”