When you come in contact with bacteria, viruses, or other substances that can make you sick.

The cause of.

When a disease is normal and expected among particular people or in a certain area.

When a disease spreads beyond what is normal or expected, infecting a lot of people in a specific population or area.

A general term describing damage or disease that affects the brain. Examples include encephalitis, meningitis, seizures, and head trauma.

Swelling of the brain caused by a virus or bacteria. Encephalitis can result in permanent brain damage or death.

When FDA temporarily allows a vaccine to be given to the general public before it has gone through the full licensure process. This can only be done during a public health emergency where the vaccine can reduce cases and deaths.…

Permanently wiping a disease from the face of the earth. To date, smallpox is the only human disease that has been eradicated although there is an ongoing worldwide effort to eradicate polio.

Reduction of the spread of disease to zero in a defined region through prevention efforts like vaccination. Cases can still be spread from people traveling into the region from other places where the disease has not been eliminated.

A measure used to describe how good a vaccine is at preventing disease. This rate measures how a vaccine performs under ideal situations in clinical trials.