Contrary to the claims made by some advocates of<unk>  vaccine<unk> s, there is no scientific evidence for the existence of "immune system overload", and according to the UK National Health Service the idea is a "myth". In addition, the amount of chemicals in vaccines such as aluminum and formaldehyde is much lower than natural exposure levels. Intentional deviation from the ACIP's<unk>  leaves children vulnerable to infection and increases the likelihood of outbreaks of vaccine-preventable diseases. These<unk> s also increase the chances of infection among individuals who could not be vaccinated for medical reasons, because they were too young, or who did not develop a sufficient immunologic response to the vaccine. After one of the most notorious outbreaks of measles in the United States, in California, legislation was passed to make<unk>  mandatory, as<unk>  vaccine<unk> ng and/or avoidance had been prevalent before the outbreak.
Alternative vaccination schedule
Pulse vaccination strategy
Active immunization
Vaccine bundling
Pre-exposure prophylaxis
Post-exposure prophylaxis
Vaccination schedule
Targeted immunization strategies