Two European patients, one in Belgium and one in the Netherlands, have been infected twice by the coronavirus, virologists say.
Belgian virologist Marc Van Ranst told VRT News that a Belgian woman was infected first in mid-March, then again in June. Her symptoms were mild enough to avoid hospitalization, he said.
“We were able to genetically sequence the virus in the two cases,” Van Ranst said in a television interview on Monday night. “And there is indeed enough difference to be able to say that this is another strain, a second infection.”
“Good news, it is not,” he said. “Because you hope of course that when you’re infected, that you’re then out of the danger zone for a long while. And hopefully that is so in most cases. At the very least, there appear now to be exceptions.”
Meanwhile, a patient was infected twice in the Netherlands, virologist Marion Koopmans told NOS, the Dutch national broadcaster.
Koopmans said it was an “older patient with a compromised immune system,” according to NOS. Koopmans confirmed to NOS that the RNA profiles of the two viruses that infected this patient differed.
The news comes after a 33-year-old man living in Hong Kong was reported to have had Covid-19 twice this year, according to preliminary research.
The pre-print study -- which the University of Hong Kong said on Monday has been accepted to publish in the journal Clinical Infectious Diseases -- found that the man’s second case of Covid-19 occurred 142 days after the first.
The study also noted that in the first case, the man showed symptoms but in the second case he was asymptomatic, in that he did not show any noticeable symptoms.
The genetic analysis showed that the first infection was from a strain of the coronavirus most closely related to strains from the US or England, which were collected in the spring, and the second was most closely related to strains from Switzerland and England, which were collected in July and August.
“This case illustrates that re-infection can occur even just after a few months of recovery from the first infection. Our findings suggest that SARS-CoV-2 may persist in humans as is the case for other common-cold associated human coronaviruses, even if patients have acquired immunity via natural infection or via vaccination,” the researchers wrote in their study.
The researchers called this the “first case” of re-infection of Covid-19 in their paper, but other experts are calling for more research before naming this case truly the world’s first.
Hong Kong researchers say man got Covid-19 twice: