World Health Organization states that without vaccines, everyone is at risk of serious illness and disability from diseases like measles, meningitis, tetanus and polio. Explaining the two key reasons to get vaccinated, WHO adds, "to protect ourselves and to protect those around us. Not everyone can be vaccinated - including infants, who are too young to be vaccinated and people with chronic illnesses or treatments that affects their immune system. They depend on others getting vaccinated to ensure they are also protected through vaccines."