Two Independent Outbreaks of Measles in Partially Vaccinated Junior High Schools, Japan
Posted by vaccinesme on Monday, January, 26 2009 and filed under Articles
Key topics: Measles Outbreak Vaccine Failure

A. Kawamoto, T. Honda, K. Ishida, T. Ozeki, H. Hayashibara, K. Shiraki and S. Hino (1995) Two independent outbreaks of measles in partially vaccinated junior high schools in Tottori, Japan. Arch Virol. 1995;140(2):349-54.

We analyzed retrospectively a relative risk of measles attacks in vaccinated vs. unvaccinated students using two independent outbreaks in Japan. The first involved 33/328 (10%) students where 64% students and 30% measles cases had been vaccinated. The second involved 27/241 (11%) students where 81% students and 48% measles cases had been vaccinated. The attack rates of vaccinated vs. unvaccinated students were significantly low (p < 0.001), but they accounted 25% in both episodes. The statistically significant clinical features among vaccinated and unvaccinated cases included the average duration of fever, 5.16 +/- 1.71 vs. 6.67 +/- 2.19 days (p = 0.01) and the incidence of complications, 0 vs. 25%, respectively. These results suggested that the measles in vaccinated cases were mostly due to secondary failures.