We may be in the middle of summer, but now is the time to get your kids their back-to-school vaccines. Health experts say it is important to not wait until the last minute to get their shots. It takes a few weeks for children to build up immunity after vaccines. Some of those vaccines include tetanus, chickenpox, polio, whooping cough and measles. There has been a recent rise in measles cases because of a dip in children getting vaccines. Health experts want all parents to know that scientists stand behind the safety and efficacy of traditional and seasonal vaccines.