“…For the IBD patients at our institution, we measured specific antibody levels for MMR, and varicella using EIA, which has a high sensitivity and high versatility. In the present study, seronegativity rates for measles, mumps, rubella, and varicella were 32.5, 37.1, 32.0, and 5.1%, respectively, similar to the rates reported by Naganuma et al [5,6]. In addition, in a study on healthcare workers in major hospitals in Japan, in which seronegativity was defined as IgG < 4 IU/mL by the EIA method, the reported seronegativity rates were 7.4% for measles, 16.1% for mumps, 8.4% for rubella, and 0.8% for varicella [4,[7][8][9][10][11], and when we computed the seronegativity rates of our IBD patients using the same cutoff value, the rate was 3.0% for measles, 37.1% for mumps, 14.1% for rubella, and 5.1% for varicella, indicating higher seronegativity rates for healthcare workers in the general population were for IBD patients, with the exception of measles.…”