coronavirus, variant, adenovirus, ampoule, antibodies, antigen, biology, bottle, care, cell, closeup, covid-19, dish, dna, doctor, epidemic, examine, experiment, face, genetic, health, illness, laboratory, liquid, material, medical, medicine, microscope, mutation, novel, pandemic, pathogen, pharmacy, phial, reproduction, research, rna, sars, science, scientist, strain, test, vaccine, version, vial, virology, virus, woman, world health organization