He believes in his own strength.

You always become my strength, thank you very much.

He is an expert in virology.

My computer got infected with a computer virus.

The Ebola virus is a very infectious virus.

The poliovirus is a virus that primarily enters the body through the mouth and destroys the nervous system.

Norovirus can be prevented by hand washing and disinfection.

The number of people infected with the new coronavirus is rapidly increasing.

A ping-pong infection occurred at school, causing many students to take time off.

Oral infection is when pathogens enter the body through food or drink.