Number of hep B booster doses needed to restore seropositivity depends on antibody titers

Last Updated: 2019-09-30

By Reuters Staff

NEW YORK (Reuters Health) - For young adults previously vaccinated against hepatitis B but found to be seronegative for hepatitis B antibodies, the number of booster doses of hepatitis B vaccine needed to restore seropositivity depends on antibody titers, researchers in Taiwan report.

As many as 50% of individuals vaccinated against hepatitis B have low or undetectable levels of anti-hepatitis B surface antigen antibody (anti-HBs) 15 years after their infant immunizations. Whether they should receive booster doses (and, if so, how many) remains unclear.

Dr. Chyi-Feng Jan of National Taiwan University Hospital, in Taipei, and colleagues investigated the responses to between zero and three booster doses of hepatitis B vaccine in 1,037 college students with an anti-HBs level below 10 mIU/mL.

Among 496 seronegative study participants administered hepatitis B vaccine booster, seropositivity rates four years later were 52.1% for those who received one dose, 78.6% for those who received two doses, and 90.9% for those who received three doses. Only 17.7% of those who received no booster dose were seropositive for anti-HBs at that time.

The researchers estimated that seropositivity rates of about 95% could be achieved with one booster dose with a baseline anti-HBs cutoff level of 2.96 mIU/mL, with two doses with levels of 0.8 mIU/mL, and with three doses with levels of 0.29 mIU/mL.

Participants in the extremely low-antibody-titer group (<3 mIU/mL) reached an acceptable seropositivity rate after 3 doses of the booster, while participants in the very-low-antibody-titer group (3-10 mIU/mL) reached adequate seropositivity rates after a single dose, the researchers report in Family Practice, online September 3.

"The results presented herein can help determine the required number of doses needed to help young adults reach a protective titre and facilitate evidence-based clinical applications," the researchers conclude. "Individuals who wish to be anti-HBs seropositive can receive the suggested one or two doses according to their initial anti-HBs titre upon college entrance, which should be a more cost-effective approach, especially if vaccines supplies are in shortage."

The study had no commercial funding, and the researchers report no conflicts of interest.

Dr. Jan did not respond to a request for comments.

SOURCE: https://bit.ly/2m1gnkz

Fam Pract 2019.