virus protection. antibodies and viral infection. immune defense of the body. attack on antigens

virus protection antibodies viral infection immune defense body attack antigens antigen antibody bacterium toxin immunity immunoglobulin coronavirus viruses microbes colony inside organism aquatic microscopic genome mutation evolution germs microbe pathogen disease cell microbiology microscope abstract bacterial research 3d epidemic pandemic medical closeup nano molecule bacillus virology scientific bacteria genetic micro macro airborne infections epidemiology cold wallpaper illustration