“The theoretical risk” of importing new Covid variants due to air travel without a mask cleared through customs in the US “exists”. Virologist Fabrizio Pregliasco, a professor at the State University of Milan, says this to Adnkronos Salute. The United States is facing the growing spread of some sub-variants of Omicron 2 that are even more contagious than the already world-dominant BA.2 itself. In the state of New York, in particular, the majority of new cases of Covid-19 are attributable to sub-lineages BA.2.12 and BA.2.12.1, the latter considered – according to the latest data reported on Facebook by scientist Eric Topol of Scripps Institute – about 20% more transmissible than Omicron 2. And now that major airlines, following a ruling from a judge, are lifting the obligation to mask, it could increase the likelihood of ‘importing’ these viruses. “In my opinion – reiterates the medical director of Irccs Galeazzi in Milan – beyond the obligation or not “indoors, which in Italy will be discussed shortly in view of the deadline of April 30,” the use of the mask during air travel, long-distance species, it remains useful. Especially if you are frail or caregiver of the frail “. Even if, the virologist acknowledges, “it is a destiny that of a transition towards normality” made up of “greater openings” and “less stringent rules”.