Polio is a contagious viral illness that in its most severe form causes nerve injury leading to paralysis, difficulty breathing and sometimes death.

In the U.S., the last case of naturally occurring polio was in 1979. Today, despite a worldwide effort to wipe out polio, poliovirus continues to affect children and adults in parts of Asia and Africa.

The Centers for Disease Control and Prevention (CDC) advises taking precautions to protect yourself from polio if you're traveling anywhere there's a risk of polio.

Adults who have been vaccinated who plan to travel to an area where polio is occurring should receive a booster dose of inactivated poliovirus vaccine (IPV). Immunity after a booster lasts a lifetime.