Effect of the revision of the recommended vaccination schedule for preventing vertical transmission of hepatitis B virus on vaccination status of infants in Japan

抄録

BACKGROUND

In 1986, a strategy of vaccinating infants at 2, 3, and 5 months of age was implemented in Japan to prevent the vertical transmission of the hepatitis B virus. This strategy was revised in 2013 to vaccinate infants at birth, 1 month, and 6 months of age. We aimed to evaluate the effect of this policy change on the vaccination status of infants born to mothers with positive hepatitis B surface antigen.

METHODS

We identified infants born between April 2009 and March 2021 from the JMDC Claims Database. Administration of hepatitis B immunoglobulin at birth was used to identify infants who received preventive measures against vertical transmission. The timing of hepatitis B vaccine administration within 12 months of birth was compared between old (born between April 2009 and September 2013) and new (born between October 2013 and March 2021) groups.

RESULTS

Among the 77,797 and 510,584 infants born before and after October 1 2013, respectively, 190 (0.24%) and 732 (0.14%) were analyzed. The proportion of infants receiving at least one dose of the vaccine increased from 63% to 96% (p < 0.001). The proportion of infants who received timely first, second, and third doses of vaccines changed from 54% to 90% (p < 0.001), 46% to 59% (p = 0.002), and 39% to 31% (p = 0.034), respectively.

CONCLUSIONS

The change in strategy against the vertical transmission of hepatitis B virus resulted in an increased rate of receiving the first dose of the vaccine and a decreased rate of timely completion of the recommended doses.