Reacción a "Reaction: three new recombinant SARS-CoV-2 variants detected"

One of the main characteristics of coronaviruses is their ability to recombine with other coronaviruses. We are now beginning to be able to distinguish these recombinations because the different variants that have coexisted in circulation are becoming more phylogenetically distant. To put it colloquially: they look less and less alike. This allows us to identify the parts of the genome that belong to different variants.

The XD lineage is a virus with an AY.4 delta genome that has acquired the spicule from the BA.1 omicron virus. The XF lineage is a BA.1 omicron virus that has a fragment in the polyprotein that regulates virus replication from the delta variant. The XE lineage has the previously mentioned omicron BA.1 variant polyprotein and the rest of its genome is BA.2 variant. Of these new lineages, the one with the most sequences published in GISAID is the XE lineage and it is the one that requires the most monitoring at the moment.

I would like to stress that these phenomena are not particular to SARS-CoV-2, but are frequent in these viruses. Their circulation is limited at the moment and we still need more data to know if they have any impact on the protection conferred by vaccines. Genomic surveillance allows researchers to monitor what is circulating and assess the impact it may have, but on a societal level I would not consider it a concern until more data is gathered.