A waiting period does not typically present an issue if multiple vaccines are given simultaneously, but in Japan multiple vaccines are less often given simultaneously than in the United States. In Japan, there has not historically been a need for simultaneous vaccination because many of the vaccines delivered in early childhood were not available until recently (eg, Hib, PCV) or not on the routine schedule (HBV). Only since the licensure of Hib and PCV has there been an opportunity to deliver multiple routine vaccines on the same day, but there are still reports of hesitation among families and providers to do so. Providing a combination vaccine might ameliorate this issue, but such vaccines are limited to Japanese-produced DTaP, diphtheria-tetanus (DT), and measles-rubella at this time. A diphtheria-tetanus-acellular pertussis plus Sabin derived injectable poliovirus vaccine (DTaP-sIPV) was introduced in November 2012, and may improve coverage but this will not eliminate the need for simultaneous vaccination.