New variants of SARS-CoV-2.

The emergence and spread of new variants of SARS-CoV-2 has produced enormous interest due to their possible implication in the improved transmissibility of the virus, their consequences in the individual evolution of the infection, as well as in the possible escape from the immunity generated by the current vaccines. The variants that attract most attention are those of public health concern, including B.1.1.7 (UK), P.1 (Brazilian) and B.1.351 (South African). This list is extended by the variants of interest that emerge and are expanding in certain countries but are found sporadically in others, such as B.1.427 and B.1.429 (Californians) or B.1.617 (Indian). Whole genome sequencing or strategies specifically targeting the spicule gene are used in the microbiology laboratories for characterization and detection. The number of infected individuals, the sanitary situation of each country, epidemiological measures and vaccination strategies influence its dispersion and new variants are expected to emerge. This emergence can only be avoided today by increasing the vaccinated population in all countries and by not relaxing epidemiological containment measures. It is not excluded that in the future it will be necessary to revaccinate against new variants.