People vaccinated against COVID-19 may be sick…See more ​‍͏

can affect vaccine protection against infection.

This is one reason updated vaccines have been developed.

3. No vaccine is 100% effective
   This is not unique to COVID-19.

The WHO emphasizes that no COVID-19 vaccine provides 100% protection against infection.

So a person can follow vaccination recommendations and still become infected.

The important question is what happens after infection.

4. People respond differently
   Two people can receive the same vaccine and develop different levels of immune protection.

Age and health can influence immune responses.

People with weakened immune systems may not respond as