Impact of coronavirus variants may be location-dependent
3/06 - A new approach to viewing viral evolution could help predict whether and when a new coronavirus variant is likely to outcompete currently dominant versions, researchers say.
"Mutations alone cannot answer the question" of whether a variant will take hold, said Venky Soundararajan of Massachusetts-based data analysis company nference. To estimate a variant's potential impact, the "distinctiveness" of its mutated gene sequences relative to previously circulating variants must be considered in the context of each geographical area, Soundararajan said. Genetic changes that confer distinctiveness in one geographical region might not do so in another region, depending on what variants had circulated there, his team said in a report posted on Thursday on medRxiv ahead of peer review.
Studying a database of nearly 8 million SARS-CoV-2 samples from around the world, the researchers tracked and compared the evolving genetic sequences of the variants to which populations in different regions have been exposed - so-called herd exposure. The distinctiveness of a lineage in a given country during a specific time window was significantly linked to its change in prevalence in that country over the next eight weeks, they found.
The researchers are working with the U.S. National Institutes of Health on a system that will alert public health officials when new variants arise to which communities are likely to be vulnerable. Those are variants that have the most differences both from the original version of the virus on which current COVID-19 vaccines are based and from variants to which local residents have acquired some immunity via herd exposure.