As parents exercise their right to refuse vaccinations, officials warn of the next wave of once (almost) obsolete diseases. In addition to medical and religious reasons for refusing vaccinations, parents in states like California can also opt out for philosophical reasons.

Aside from the metaphysical reasons, many parents might point to the actual number of vaccinations children have to endure: as many as 24 by the age of two, with many of the shots given to infants. (Four month olds may be stuck with four different needles every few months for the first year of life. Not fun for the parents or the child.) Additionally, many parents fear a potential connection between the increased number of vaccinations and exponential increase in autism cases. This is eventhough there has been no official study proving a link.

Officials warn of the potential return of diseases such as Polio, Whooping Cough, Chicken Pox, and Diptheria as the number of abstentions increase.