Vaccines are biological preparations that teaches the body how to fight against a particular disease by generating an immune response. A vaccine typically contains a component that resembles a disease-causing microorganism and is often made from weakened or killed forms of the microbe, its toxins or one of its surface proteins. Messenger RNA (mRNA) vaccines teach our cells how to make a protein that will trigger an immune response inside our bodies.


Around 25 human vaccines are available for use against different infectious diseases that are vaccine preventable. Smallpox is an infectious disease that was eradicated through vaccination. Infectious diseases such as polio and diphtheria are now rarely reported due to widespread vaccination in many settings of the world. If a child is not vaccinated against vaccine preventable diseases, severe illness or even death may occur.

Page created on 16 March 2015

Page last updated on 10 February 2022

References: World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC).