Infectious diseases are diseases caused by bacteria, viruses, fungi or parasites. These are also called micro-organisms.
You can get an infectious disease by consuming contaminated food or drinks, by inhaling micro-organisms that float in the air or through contact with someone who is infected. There are many harmless infectious diseases from which you do not become very ill and that disappear by themselves.
Other infectious diseases can be dangerous. You can become very ill and develop serious complications. Older people and young children are particularly susceptible to infectious diseases and are at the greatest risk of serious complications or death. Vaccination reduces the risk of serious disease and complications and ensures that dangerous infectious diseases are less common.
For many infectious diseases, herd immunity, group immunity or group protection is of great importance. That means that when many children are vaccinated against a certain infectious disease, this disease becomes less common. Children who are not vaccinated are also less likely to get the infectious disease. They are protected by the group of vaccinated children. In order to create and maintain this group protection, it is important that as many children as possible are vaccinated. If almost all children are vaccinated, a disease may even disappear altogether.
The Dutch National Immunisation Programme protects against 12 different infectious diseases.