Serological assessment of measles-rubella vaccination catch-up campaign among university students.

BACKGROUND

In Japan, 5000-300,000 persons contracted measles every year until 2001. The measles/rubella-combined (MR) vaccination at age 17-18 years (phase 4 MR vaccination: MR-IV) was launched in 2008 in Japan as a measles-rubella catch-up campaign. A serological assessment of this campaign has not been thoroughly performed.

METHODS

Titers of anti-measles and anti-rubella immunoglobulin G antibodies, and past medical history including measles and rubella vaccination and infection were obtained from first-year university students in 2008 and 2009, and the immune status against measles and rubella was compared between students at the target MR-IV age (the target age group) and those 1 year older than the target age (non-target age group).

RESULTS

A total of 186 students were in the target age group and 146 were in the non-target age group. The proportion of students with a history of measles and rubella infection was not significantly different between the two groups (8.8% vs. 6.3%, P = 0.41 and 11.0% vs. 9.9%, P = 0.75, respectively). A history of two or more measles and rubella vaccinations was significantly more frequent in the target age group (85.2% and 54.9%, respectively) than in the non-target age group (20.8% and 13.2%, respectively; both P < 0.001). Prevalence of seropositivity for measles and for rubella was also higher in the target age group (98.9% and 97.8%, respectively) than in the non-target age group (91.0% and 87.5%, respectively; both P < 0.001).

CONCLUSIONS

The MR-IV catch-up campaign helped achieve herd immunity and will contribute to the elimination of measles and rubella.