Cumulative Vaccination Coverage of the Second Dose of Measles-Rubella Vaccine in Preschool Children: Results of the 2008 Nationwide Survey in Japan

摘要

It has been demonstrated that decreasing the number of susceptible persons through proper vaccination of the measles vaccine can prevent measles epidemics. In Japan, a 2-dose schedule of measles-rubella (MR) combination vaccine was introduced in 2006, in which the first dose is to be given at age 1 (Stage I) and the second dose to be given for preschool children at age 5–6 (Stage II). In 2007, a nationwide survey on 5,000 randomly selected children at age 6 from various parts of Japan revealed that the cumulative vaccination coverage (CVC) for the second dose of MR vaccine was only 80.3% at the end of Fiscal Year 2006. The 2008 Survey showed that the cumulative vaccination rate increased gradually from early April to late October in 2007, surpassing the corresponding rate during the same period in 2006 by 20–30%. The cumulative vaccination coverage increased at a slower pace from early November 2007 to early January 2008, whereas in mid-January it began to increase at a pace similar to that observed before October 2007. It then showed a steep increase in March 2008, reaching the final CVC of 90.6%. In order to reach the cumulative vaccination rate of 95% or higher for Stage II children at the end of each fiscal year, it is desirable to continue encouraging parents to have their children vaccinated with the second dose of MR vaccine before the influenza vaccination period starts.