Why Some People Never Catch the Flu

Some people never get the flu. This is strange because the flu virus spreads easily from person to person.

Why does this happen? Some people have a strong immune system. Their body fights the virus fast, before they feel sick.

Also, some people had the flu before but did not know it. They had no symptoms, but their body made protection against it.

Sleep, stress, and health also matter. People who sleep well and feel less stress often get sick less.

Vaccines can help too. A vaccine gives your body protection without making you sick first.

But the flu virus changes every year. So a person can be safe one year, but get sick the next year.