ATLANTA – A federal vaccine advisory panel is considering options for ensuring that health care personnel who were vaccinated against hepatitis B in the remote past are currently protected.
Increasing proportions of health care personnel were vaccinated against hepatitis B in infancy, or as a catch-up during adolescence. An estimated 90%-95% of healthy adults aged 40 years and younger achieve a protective antibody titer (defined as anti–hepatitis B surface antigen concentrations of 10 mIU/mL or greater) after receiving the three-dose series (MMWR 2011;60[RR07]:1-45).
However, there is currently no recommendation for postvaccination serologic testing to ensure protection, and records may no longer be available for some people who did have such testing earlier in their careers. Health care schools and other institutions are now seeking guidance to ensure hepatitis B protection for students and workers, said Dr. Sarah Schillie of the Centers for Disease Control and Prevention.
Current CDC recommendations for immunization of health care providers call for all unvaccinated individuals whose activities involve "reasonably anticipated risk for exposure to blood or other infectious body fluid" to be vaccinated with the complete three-dose hepatitis B vaccine series prior to contact with blood. Postvaccination serologic testing (at 1-2 months after the last dose) is recommended for all providers at high risk for occupational exposure to blood or body fluids. Revaccination is recommended for those with hepatitis B surface antigen (anti-HBs) concentrations less than 10 mIU/mL.
However, anti-HBs levels wane over time following vaccination, and an anti-HBs level of less than 10 mIU/mL years after vaccination doesn’t distinguish between people who responded initially and are still protected, those who have a delayed response and would likely respond to a second series of three additional doses, and nonresponders who would be susceptible to infection even after six doses (or who might have past or chronic HBV infection), Dr. Schillie explained.
The following three options are currently under consideration by the CDC’s Advisory Committee on Immunization Practices (ACIP):
• No action unless exposed. This strategy relies on the provider’s timely reporting of a percutaneous or mucosal exposure to blood or body fluids. The individual is then assessed for both hepatitis B vaccination history and serologic anti-HBs testing, and the source patient is tested for anti-HBs. The decision to give hepatitis B vaccination (HBV) and/or hepatitis B immune globulin is based on the results.
• Pre-exposure anti-HBs. If the level is above 10 mIU/mL, no further action is needed. If the anti-HBs level is less than 10 mIU/mL, one dose of HBV is given and the individual is retested 1-2 months later. If the anti-HBs level is still less than 10 mIU/mL, current recommendations for revaccination and retesting should be followed.
• Challenge dose of HBV. One dose is given at the time of school matriculation or hiring, and the anti-HBs level is measured 1-2 months later. If the level is more than 10 mIU/mL, no further action is needed. If it’s less than 10 mIU/mL, then current recommendations for revaccination and retesting should be followed.
Many health care systems in the United States are already using one of these options, Dr. Schillie noted.
Dr. Mark H. Sawyer, chair of the ACIP hepatitis B working group, said that a cost-effectiveness analysis of the three options will be presented to the ACIP at its June 2012 meeting, and a vote could be taken at its October 2012 meeting.
Dr. Sawyer and Dr. Schillie have no relevant disclosures.