Vaccination is a safe and simple way to strengthen the immune system to build resistance against disease-causing germs. Once vaccinated, an individual will have a level of protection (or immunity), against that specific harmful disease. Vaccines contain a part of the virus/bacteria in a weakened, live or killed state, which will trigger a response from the immune system. It is important to be aware that vaccines do not cause disease or health complications.

A vaccine trains your immune system to recognise and combat viruses/bacteria. When exposed, antibodies are naturally produced by the immune system to fight the disease. If the bacteria or virus reappears, the immune system will remember how to respond and quickly destroy it.

Before a vaccine is introduced into the population, it must go through rigorous testing and clinical trials, where it is administered and monitored in groups of volunteers. Once a vaccine is shown to be safe and effective, it is approved by national regulators, manufactured to exacting standards, and distributed.

Vaccines are mostly given through injection, but some are administered orally (by mouth) or sprayed into the nasal cavities.

Simply put, vaccination prevents disease and saves lives. It is a safe and effective way to protect oneself and those around you. Some individuals, for instance, those who suffer from a serious illness, are unable to take certain vaccines. These individuals depend on others to get vaccinated to reduce the spread of disease. Regular vaccination is needed to keep children healthy, prevent outbreaks and to eventually eradicate infectious diseases altogether.

Infectious diseases spread easily and entire communities can rapidly become infected. If a high percentage of the community is vaccinated, it is difficult for the disease to spread. This is known as ‘herd immunity’ and is especially crucial for those most vulnerable, who are unable to receive certain vaccines. This includes infants, those undergoing certain medical treatments for instance cancer, and those suffering from health conditions that impair the function of their immune system, including HIV.

The reason is simple; if you get sick you could spread the disease to friends, family, and those most vulnerable around you.


The NICD is part of the VSN a global network of websites, established by the World Health Organization, that provides reliable information on vaccine safety. It is a network of a diverse group of digital information resources (websites and social media), VSN members, located in countries around the world and providing scientifically based information on vaccine safety in various languages.