All people can have and transmit different variants of the virus that causes Covid-19 with different genetic sequences simultaneously, which undoubtedly has implications for the evolution of new variants
It has been discovered by a team from Case Western Reserve University (USA) who carried out the analysis of the complete DNA sequence of the virus.
The researchers found wide genetic variation in SARS-CoV-2 viruses among 360 patients whose viral infections were genetically sequenced, showing that all individual infections included multiple variants of the virus.
Reports on the virus often highlight a single dominant strain, leading to underestimation of the genetic variation of the virus and can have serious consequences for public health planning and response.
“Our work warns of the complexity of infectious diseases, which is often oversimplified when considering only the most abundant virus in an infection, and we demonstrate the importance of examining variations that are historically considered noise,” says Ernest Chan. “We see that the genetic variants observed in low frequency in SARS-CoV-2 infections may be early indicators of new strains responsible for subsequent upticks in transmission.” The article is published in «PLOS Genetics»
The team performed full genome sequencing of SARS-CoV-2 viruses from 250 patients and used similar data from a further 110 patients with full genetic sequences of the infecting viruses provided through international research collaborators.
This data was obtained in the early days of the Covid-19 pandemic, when the Alpha variant and then the Delta variant were of great concern.
The work showed that the mutations found in Omicron BA.1 and BA.2 were already present as relatively minor variations at least a year before Omicron and its many iterations became “variants of concern.” Omicron and its own variants were instrumental in a major Covid-19 resurgence last winter.
Omicron and its own variants were instrumental in a major Covid-19 resurgence last winter
“Focusing on major variants is a critical first step in developing diagnostics, therapeutics and vaccines; however, variations need to be quantified and reported by the research community so that the public health community and the general public are better prepared and more agile in responding to this ever-evolving virus,” says researcher Peter Zimmerman. .
Although work continues to define and trace the emergence of virus lineages throughout the ongoing evolution of SARS-CoV-2 worldwide, due to urgency the focus is on tracking and reporting variations. relatively dominant, but the Case Western Reserve University researchers believe that, given the multiple variations within individual infections, it is important to report a more complete representation of viral genetic sequences to understand how these genetic changes may spread and potentially interact with different hosts. categories of patient conditions, including evasion of eradication efforts.