Do childhood vaccines protect young HCWs?
CDC considers options for HBV response
In the age of safer needles, vaccination and prophylaxis, the risk of hepatitis B among health care workers has dropped dramatically, from a high of about 12,000 cases a year in the 1980s to 203 reported acute cases from 2005 to 2010. Routine HBV vaccination of infants, which began in 1991, promises to make transmission from blood and body fluid exposures even rarer.
But universal vaccination also has raised some difficult questions: How do you handle young employees who had the vaccine as infants but never were tested for an immune response? Do you assume they are protected? Or do you re-vaccinate everyone? And does the HBV immunity wane over time?
A group of experts is now working to draft advice for hospitals on handling these new issues. About 92% of infants and young children are vaccinated against HBV.
"It is a very challenging question," says Mark Sawyer, MD, a pediatric infectious disease specialist from the University of California, San Diego, and chair of the hepatitis workgroup of the Advisory Committee on Immunization Practices, a panel that advises the Centers for Disease Control and Prevention. "There's a lack of hard data on lots of things you'd like to be sure about in this equation."
CDC currently recommends a three-dose series of HBV vaccine for health care workers. More than 90% of health care workers will respond if they receive the full series. Many non-responders will show an immune response to an additional one to three vaccinations, but a small portion (about 5%) of health care workers remains non-responders.1
If non-responders have a bloodborne pathogen exposure and the source patient is positive for hepatitis B surface antigen, they should receive hepatitis B immune globulin and additional vaccination, the CDC says.
About 9 in 1000 source patients test positive for hepatitis B surface antibody, says Sara Schillie, MD, MPH, MBA, medical epidemiologist at CDC. There are about a million people in the United States who have chronic HBV infection.
Several options have emerged as CDC considers this quandary, but two were receiving the greatest focus, Schillie says:
Post-exposure protection: Document previous HBV vaccination, but don't test for titers or revaccinate. Monitor for exposures, then screen and revaccinate employees after an exposure. "The problem with that approach is it doesn't help people who don't report," says Sawyer. Only about half of all trainees and health care workers report their bloodborne pathogen exposures, according to the CDC. Employees also would need to have documentation of their HBV vaccination as infants.
Pre-exposure testing: Get a baseline test of HBV antibody levels for all employees at risk of bloodborne pathogen exposure and revaccinate those with low antibody levels. Antibody levels are known to drop in infants after vaccination, says Sawyer. "We don't know that they're less well-protected just because their antibody levels go down," he says.
Another option would be to revaccinate all health care workers as trainees or new hires, then test for antibody response, says Sawyer.
Regardless of the option chosen, hospitals still will be required to offer the hepatitis B vaccine to health care workers. That is a requirement under the Bloodborne Pathogen Standard of the U.S. Occupational Safety and Health Administration.
The CDC is conducting studies of the long-term effectiveness of the HBV vaccine. "Over time, we'll be able to address this more clearly," says Sawyer.
Reference
- Centers for Disease Control and Prevention. Immunization of Healthcare Personnel – Recommendations of the Advisory Committee on Immunization Practices. MMWR 2011; 60:1-45.
You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
- Award-winning Medical Content
- Latest Advances & Development in Medicine
- Unbiased Content