omicron, coronavirus, mask, virus, africa, ban, case, classification, covid-19, covid-19 variant, delta, doctor, globe, map, dropout, epidemiological, epidemiology, evolution, face, face mask, female, gene, hold, increasing, infection, limit, mutation, new, new covid variant, omicron variant, one person, reinfection, restrict, risk, safety, tag-ve, text, travel, variant, who, woman, world health organization
