republic of congo, travel thed through europe, so there was a wide variety of people wearing masks on airplanes. you re in close proximity, so it s a good idea to have extra layers of protection. there s nothing like added layers to prevent potential of spread. arthel: absolutely. and, listen, there have been other variants in between delta and omicron. explain why these different variants continue to crop up. well, the thing is about this virus just like other viruses, the more opportunity it has to spread, the more opportunity it has to replicate. and when it replicates, it mutates. when it mutates, vernallingly you may end up with a mutation that makes it more contagious, makes it more lethal, makes it have more severe disease or could potentially evade the immune responses general rated by the vaccines and also reduce the effectiveness of treatments like monoclonal antibodies.