An entire family-of-four tested positive for coronavirus then all fell ill again two months later - after making a "full recovery".
Chuck Conboy Sr., 67, said his wife and two sons all tested positive for Covid-19 in November but he then he did so again nine weeks later.
Mr Conboy, from Nebraska, US, claims they were all feeling better by the new year before he began feeling tired and feverish again in January, with the symptoms becoming worse the second time round.
His wife and children each lost their sense of taste and smell, he says, with all four of the family falling ill for a second time.
However given the prevalenceof "long covid" - with patients suffering symptoms and side effects months after their original diagnosis - it is possible they never fully recovered from their infections the first time round.
He said: “I woke up… and had a fever. It jumped up to like 102 degrees (40C), which for me, that’s high. I thought, ‘Oh, my God, not again.’”
He said the second round felt much worse than the first.
“It just hit me like a truck, and this time, it knocked me down. In fact, this is the first day - day nine - that I’m back to halfway normal. If you’d asked me yesterday, I didn’t even know where I was."
Medical experts say catching Covid-19 twice is possible but so far exceedingly rare, as Covid-19 antibodies are believed to impart immunity for around six months.
Researchers are still investigating the life of the virus, as new mutant strains sweep the world.
Whether people can be reinfected is a key question for the global vaccine effort.
Experts have said it is possible the vaccines will have to be administered repeatedly over time if immunity wanes and new mutant strains prove resistant, much like the annual flu jab.
Medical journals have documented a very small number of cases where people have caught the virus a second time many months later.
A recent study in the British Medical Journal also noted it can take more than four weeks for the body to clear the virus and stop actively shedding it.
Nebraska medic Dr Mark Rupp told US media repeat infections with Covid-19 were rare but not unheard of.
He said there was not yet strong evidence that immunity lasts for several months for everyone who catches the virus
Dr Rupp explained: “That may be one of the explanations: that people with very mild disease don’t mount as vigorous an immunological response and don’t have as long-lasting a response."
