Viruses are the world's smallest parasites that can infect humans by attacking our cells. Once the virus has infected a host cell, the virus reprograms the cell to produce more virus particles. Virus particles consist of nucleic acid that is surrounded by a shell of proteins and or membranes.
Coronavirus
SARS-CoV-2, better known as the coronavirus that causes the disease COVID-19, belongs to a larger strain of viruses known as betacoronaviruses.