A man in his 60s with cancer and admitted to Yale New Haven Hospital housed three different variants of SARS-CoV-2 inside his body that coexist.
An approximately 60-year-old cancer patient resulted positive for Covid for (at least) 471 days. The rare and singular case of man has been described in scientific literature because they originated within his body three variants of SARS-CoV-2 that are coexisting.
3 variants born in 15 months
The epidemiological history of the man came out by examining the samples of patients of the Yale New Haven Hospital (USA): a variant appeared repeatedly, the B.1.517, which after April 2021 had died out in every monitored area in the USA, except than in that hospital. When epidemiologist Nathan Grubaugh and Yale researcher Chrispin Chaguza analyzed the swabs they realized they came from the same person and began studying the evolution of the virus within the human host. The preliminary results were published on a pre-press server (not revised): the man (whose other characteristics are unknown for privacy), infected for the first time in November 2020, in 15 months it hosted at least three genetically distinct versions of the virus. Each version had dozens of mutations and it seemed to coexist in the patient’s body. Had they spread externally, the three resulting viruses could have been named as distinct new variants, but, in this case, although the patient remained contagious in the course of the study, the variants in question never spread externally.
An evolutionary path (not the only one)
The research is important because it serves to shed light on how new variants emerge: that of the reservoir of mutations within people with persistent infections, perhaps immunocompromised, one of the ways, but not the only one. The virus can also evolve in infected animals or in classic person-to-person transmission. The recent study recalls another case of an immunocompromised patient described in another work: in that case the researchers had documented the evolution of the virus in 12 weeks and shown that the virus that originated from that person had infected at least five other subjects.
Competitive mutations
They are rare occurrences and it is not even known how common, however, dozens of strains of SARS-CoV-2 are registered and monitored every day by international databases and not for this reason they spread and create new variants. It is interesting to see how some of the same viral mutations tend to occur in more people with persistent infections: it could suggest that the next competitive variant could evolve with those mutations, which evidently give a competitive advantage. Studying rare cases can give scientists an indication of how the virus is moving and in which direction.
September 1, 2022 (change September 1, 2022 | 09:57)
© breaking latest news