One of the three variants represents about 70 percent of the viral genomes analyzed in the study and which is characterized by "a very specific mutation" that affects the regions where the antibodies are linked.

"We have now verified in this study, done in collaboration with the Gulbenkian Institute of Science [IGC], that the variants that are characterizing this second wave in Portugal have mutations that were not described during the entire first wave", said João Paulo Gomes, responsible for bioinformatics unit of INSA's Department of Infectious Diseases.

The three most frequent variants, each recognized by a different change in Spike protein (A222V, S477N or S98F), were detected in all regions of Portugal mainland, suggesting that they were the ones mainly co-responsible for the second epidemic wave.

The coordinator of the "Study of the genetic diversity of the new coronavirus SARS-CoV-2 (COVID-19) in Portugal" explained that this situation results from "a process of adaptation of the virus to humans".

“It’s normal for this to happen, it’s been a year since the virus appeared to infect humans, so it’s perfectly normal,” he said, exemplifying that “the UK variant that appeared now is one more and will not be the last, unfortunately”, and that causes concern.

Regarding the mutations observed in the country, the researcher stated that some "are quite interesting", but are not exclusive to Portugal, stressing that "one of the mutations characterizes a variant that appeared in Spain a few months ago and that spread throughout the rest of Europe at an amazing speed” and that was now observed in Portugal.

Asked if this variant is more lethal and if it can explain the increase in cases in the second wave, the researcher stated that in clinical terms there is no evidence of this.

The increase in cases may be justified by the existence of genetic variants with more transmission capacity, but the researcher considers that social behaviour is the basis of the largest number of cases in the second wave.