To evaluate the influence of vaccination dose and clinico-demographical factors on immune status against measles, rubella, mumps, and varicella viruses among university students, we conducted a case-control study by analyzing serum antibody titers according to past immunization and infection, and perinatal histories, using a multivariate regression model. A total of 1370 medical, paramedical, and pharmaceutical students were included in the analysis. Two or more doses of measles and rubella vaccination yielded notably greater odds ratios for immuno-positivity (9.1
95% confidence interval (CI), 2.8-28.9 and 12.2
95% CI, 0.71-210.3, respectively), compared with 1-dose vaccination, even though the superiority did not reach statistical significance for rubella. Students having younger/older siblings were more likely to be immuno-positive for mumps (2.5
95% CI, 1.3-4.9 and 2.7
95% CI, 1.4-5.5, respectively). On the other hand, post-term birth or macrosomia was associated with seronegative rubella virus antibodies. We concluded that a 2-dose vaccination strategy could successfully prevent measles and rubella outbreaks by increasing immunity.