new coronavirus or sars-cov-2 variant delta b.1.617.2 blue

delta variant pandemic infection virus disease mutation pathogen coronavirus medical illustration contagious outbreak health flu epidemic strain covid19 covid corona mutated protection new people sars treatment vaccine global seamless influenza art b16172 interest background case lineage doctor mutant infect spread variation research genetic awareness concern icon isolated red medicine blue sars-cov-2 617 b 1 617 2 abstract vector