omicron variant and its subtype ba.4. the arrow shows a dramatic increase in disease. white text on dark blue background.

529 abstract are arrow ba4 backdrop background banner blue care concept corona coronavirus cov covid covid19 dark design different disease dramatic drawing element epidemic frame graphic health icon illustration increase infection its line lineage medical mutant mutation omicron omikron pale pandemic pattern sars shape shows sign size spike subtype symbol text texture variant variation vector virus viruses white