A lab assistant points at charts of a sequenced Covid-19 virus at the Wellcome Sanger Institute that is operated by Genome Research in Cambridge, England, Thursday, March 4, 2021. After dropping most coronavirus restrictions in February 2022, Britain is now ending some COVID-19 testing and monitoring programs, a move some scientists fear will complicate efforts to track the virus and detect worrisome new variants. (AP Photo/Frank Augstein, File)