If you are tempted to delay any vaccinations for your children, it’s critical that you educate yourself about the diseases those vaccinations are intended to prevent. As an increasing number of parents are delaying or forgoing certain vaccinations, it’s no longer possible to simply assume these diseases will remain so rare that they are not a threat. Exit herd immunity. Find out about the diseases themselves.... tetanus not spread person to person but spores in dirt as a source. Mumps can cause issues with males later on.