Vaccines for children are not mandatory as a general rule, although they are strongly recommended to provide them with protection against diseases that can cause serious illness, up to and including death. Vaccines however are mandatory for children in situations such as attending daycare or school, depending on the region and laws for that area. Not everyone is able to receive vaccines as some people are immuno-compromised or have a medical condition that prevents them from being able to get vaccinated due to an increased risk of serious, potentially life-threatening side effects. In these cases, the risks that come from receiving a vaccine do not outweigh the benefits, and it is for this reason that it is recommended that every person who is able to is vaccinated, to provide protection for those who cannot. This creates what is called herd immunity as it prevents the spread of diseases through a population where the majority of people have been vaccinated. The immunization schedule provides a complete list of vaccinations recommended for children from birth up to 18 years of age, administered at regular intervals that will maximize their effectiveness against many communicable diseases.