World Immunization Week is an annual event observed in the last week of April. It aims to educate the public about why vaccines are necessary for the health of millions of people around the world.

For numerous reasons, children and adults miss out on essential vaccines which increases their risk of contracting various preventable diseases such as polio, measles, and smallpox.

The purpose of this week is to identify challenges in gaining access to vaccines and overcome those barriers for the benefit of the global population. People now realize that unless everyone is safe from disease, nobody is truly immune.

https://www.who.int/campaigns/world-immunization-week