Cost Analysis of Single-dose Hepatitis B Revaccination among Infants Born to Hepatitis B-infected Mothers Not Responding to the Initial Vaccine Series

Each year in the United States, about 20,700 infants are born to mothers who are hepatitis B surface antigen (HBsAg)-positive. Without intervention, 40-90% of such infants become infected, and approximately 90% of infected infants develop chronic hepatitis B virus (HBV) infection, which is associated with premature death from cirrhosis or cancer of the liver in 25% of persons infected during infancy.

Perinatal HBV infection can be prevented if infants receive hepatitis B (HepB) vaccine and hepatitis B immune globulin within 12 hours of birth, followed by completion of the vaccination series. Post-vaccination serologic testing (PVST) is recommended for infants born to HBsAg-positive mothers. Infants with anti-HBs levels <10 mIU/mL are considered non-responders and should receive revaccination.

The goal of the NEEMA project was to compare a single dose revaccination strategy to the previously recommended three dose revaccination strategy for infants not responding to the initial vaccine series. In the three dose strategy, infants born to hepatitis B-infected mothers who do not respond to the initial three dose vaccine series (anti-HBs <10 mlU/mL and HBsAg negative) are given three more HepB doses at three different visits, with a final PVST conducted at the end of the revaccination series. In the single dose strategy, non-responder infants are revaccinated with one additional HepB vaccine dose followed by a second PVST. Infants who are not protected after a single revaccination dose go on to receive two additional doses followed by a third PVST (i.e., three full revaccination doses in total), mirroring the three dose strategy. Since the cumulative risk of hepatitis B infection is assumed to be the same in both strategies, the primary output of interest is the cost per person from the societal perspective. The analysis included three epidemiologic scenarios that varied levels of previous protection among infants indicated for revaccination.

The lowest cost of revaccination could be achieved when all vaccination visits occurred during a previously scheduled well-child visit, and the cost of intervention included only cost of vaccine, vaccine administration, and PVST. The highest cost could be achieved when all revaccination visits were previously unscheduled, and the cost additionally reflects the need for caregivers to take time off work to take children to be vaccinated and cost for travel to the clinic. In all analyses, the single dose revaccination strategy was a lower cost option compared to the three dose strategy. If all three vaccination visits occurred during a previously scheduled well-child visit, a single dose revaccination reduced the cost per individual by $28.29-$52.73 in 2016 USD depending on the scenario. If all revaccination vaccine visits were previously unscheduled, the incremental decrease in cost per individual reached $119.81-$155.72 in 2016 USD.

The Advisory Committee on Immunization Practices (ACIP) provides advice and guidance to the Director of the CDC regarding effective control of vaccine-preventable diseases in the United States. In February 2017, informed by these results, ACIP voted to approve single-dose revaccination for infants born to HBsAg-positive mothers not responding to the initial vaccine series (recommendation effective from January 2018). Three-dose revaccination will be maintained as an ACIP-recommended alternate strategy, depending on clinical circumstances or family preference.