Nearly one-third of kindergartens in San Diego county now have vaccine exemption rates above eight percent, the level at which a school loses its herd immunity and becomes vulnerable to epidemics of childhood diseases like measles or whooping cough.
Nearly one-third of kindergartens in San Diego county now have vaccine exemption rates above eight percent, the level at which a school loses its herd immunity and becomes vulnerable to epidemics of childhood diseases like measles or whooping cough.
