appetizing hot dog on a white background

screenshot circle flower organ light illustration purple art petal design yellow pattern darkness blue font theme viruses pandemics virus close-up macro epidemics disease infection outbreak contagion spread symptoms diagnosis treatment vaccine medication immunity resistance public health hygiene quarantine isolation mortality morbidity transmission incubation period carrier vector mutation genetic variation pathogen bacteria fungus parasite clinical trials medical research antivirals antibiotics immune system zoonotic diseases vector-borne nosocomial infections multidrug-resistant pandemic preparedness response planning crisis global security community viral hemorrhagic fevers antiviral