A newly discovered antibody was able to neutralize not only all strains of COVID-19, but other coronaviruses known to cause respiratory infections in humans — a potential silver bullet for a whole class of deadly, flu-like viruses.

Mutant viruses: As viruses spread, they undergo tiny genetic mutations, and when we find a unique version of the virus, we call it a new strain.

Occasionally, new strains appear that can spread more easily, evade the immune system, or cause more severe disease.