Article ID: JJID.2022.187
A catch-up campaign of measles and rubella (MR) vaccinations was conducted for third-year high school (MR-4) students between 2008 and 2012 as part of governmental policy. We examined three analytical methodologies for the assessment of vaccination policy. We measured the antibody titers of the first-year students involved and not-involved in the catch-up campaign, and analyzed the increase in antibody titers after two-or-more-dose vaccination using conventional regression analysis, proxy exposure analysis with the individual’s birth year, and two-stage least square (2SLS) regression with the birth fiscal year as an instrumental variable. Among 379 students invited to participate in the study, 220 (58.0%) and 213 (56.2%) were included in the analysis. Conventional regression analysis revealed that two-or-more-dose vaccination produced 0.27 (95% confidence interval [CI], 0.04 to 0.49) greater log-scale antibody titers against measles. Proxy exposure analysis with the birth year revealed that two-or-more-dose vaccination produced 0.40 (95% CI, 0.18 to 0.63) greater log-scale antibody titers against measles. According to 2SLS regression, two-or-more-dose vaccination produced 0.72 (95% CI, 0.31 to 1.13) greater log-scale antibody titers against measles. All three analyses showed similar trends but no findings for rubella. These results were consistent throughout three different analytical methodologies used to assess the vaccination policy.
