Covid-19 patients may experience more severe symptoms the second time they are infected, according to research released Tuesday confirming it is possible to catch the potentially deadly disease more than once.

A study published in The Lancet Infectious Diseases journal charts the first confirmed case of Covid-19 reinfection in the United States — the country worst hit by the pandemic — and indicates that exposure to the virus may not guarantee future immunity.

The patient, a 25-year-old Nevada man, was infected with two distinct variants of SARS-CoV-2, the virus that causes Covid-19, within a 48-day time frame.

Researchers say the potential for reinfection could impact how governments plan to exit the pandemic Photo: AFP / TAUSEEF MUSTAFA

The second infection was more severe than the first, resulting in the patient being hospitalised with oxygen support.

The paper noted four other cases of reinfection confirmed globally, with one patient each in