[Safety and efficacy in two-dose vaccination using measles and rubella combined (MR) vaccine].

Measles and rubella combined (MR) vaccine and two-dose-vaccination have been used in Japan since 2006. only children undergoing monovalent measles and rubella vaccination undergo a second vaccination. We intend to administer MR vaccine twice to Japanese children from 2011, so studied the safety and efficacy of two-dose MR vaccination. Subjects were 75 pre school children undergoing MR vaccine manufactured by Biken at one year old in a clinical trial. Children were observed for adverse events for 28 days after the second MR vaccination. Efficacy was determined by measuring antibodies for measles and rubella before and after (six to eight weeks later) the second vaccination. Results showed that fever frequency decreased significantly from 27.3% to 14.9% (p < 0.05), and eruption decreased from 12.2% to 6.8% from the first to the second vaccination, whereas, the frequency of redness and swelling at the inoculation site increased from 7.3% to 10.8% and 2.9% to 8.1%. Differences are not statistically significant. Measles antibody titer determined by NT assay and rubella antibody titer measured by HI assay increased significantly from prevaccination to postvaccination (p < 0.0001). Measles antibodies measured by NT and EIA assays and rubella antibody measured by HI assay turned positive in all subjects after the second MR vaccination. In conclusion, two-dose MR vaccination should be safe and effective in eliminating measles and rubella in Japan.