@article{oai:dmu.repo.nii.ac.jp:00001500,
 author = {Ohyatsu, Mariko and Ishikawa, Yayoi and Chibana, Yoko and Watanabe, Naomi and Ohrui, Masami and Tsuchida, Kohei and Tominaga, Keiichi and Murohisa, Toshimitsu and Iijima, Makoto and Hiraishi, Hideyuki},
 issue = {1},
 journal = {Dokkyo Journal of Medical Sciences},
 month = {Mar},
 note = {Objective：To investigate the significance of additional hepatitis B （HB） vaccination in medical students who were unresponsive to a primary vaccine series or those who had lost antibody to hepatitis B surface antigen （anti-HBs）.

Methods：Subjects were followed up for 3 years after completion of a primary HB vaccine series. One additional dose was given to those who lost the anti-HBs within 3 years after the initial series, while 3 doses were given to those who had not responded to the initial vaccination. Subjects：100 medical students （59 men and 41 women；mean age on admission to university, 19.4±1.6 years） enrolled at the School of Medicine, Dokkyo Medical University in April 2012.

Results：The rate of positivity for anti-HBs was 98％ soon after completion of the primary HB vaccine series and decreased without the need for additional vaccination to 79％, 61％, and 55％ at 1, 2, and 3 years after the primary series, respectively. Eighteen vaccinated subjects （18％） lost the anti-HBs 2 years after the primary series, and all of them responded to 1 additional dose. Another 18 successfully vaccinated subjects （18％） were anti-HBs negative both 1 and 2 years after the primary series；17 of them responded to 1 additional dose. As for 2 subjects （2％） who were unresponsive to the primary series, 1 became anti-HBs-positive for the first time after 3 additional doses given 2 years after the primary series.

Conclusion：A number of students became or remained anti-HBs negative after the primary HB vaccination, indicating that its timing and dose of additional vaccination need to be studied further to evaluate its utility.},
 pages = {1--8},
 title = {Results of Hepatitis B Vaccination 3 Years After a Primary Vaccine Series in Medical Students},
 volume = {45},
 year = {2018}
}