CDC: Flexibility will remain on HBV

Options for testing young HCWs

Flexibility will be the guiding principle in upcoming recommendations on health care workers who were vaccinated against hepatitis B as infants.

Instead of directing hospitals to test all young health care workers for antibodies to hepatitis B surface antigen, the Centers for Disease Control and Prevention will present two approaches, medical epidemiologist Sara Schillie, MD, MPH, MBA, told the Advisory Committee on Immunization Practices (ACIP).

“There’s not a right or a wrong approach,” she told HEH.

Universal HBV vaccination of infants is a public health success — and a new challenge for health care employers. Health care workers who were vaccinated against hepatitis B as infants were never tested for an antibody response.

CDC currently recommends a three-dose series of HBV vaccine for health care workers. More than 90% of health care workers respond to the full series. Many non-responders show an immune response to an additional one to three vaccinations, but a small portion (about 5%) of health care workers will remain non-responders.1

If non-responders have a bloodborne pathogen exposure and the source patient is positive for hepatitis B surface antigen, the exposed health care worker should receive hepatitis B immune globulin and additional vaccination, the CDC says.

For new hires who were vaccinated as infants, employers can take a pre-exposure or post-exposure approach, according to proposed recommendations discussed by ACIP.

In the pre-exposure approach, trainees or newly hired workers who were vaccinated as infants would be tested for HBV antibodies. If they have a level of at least 10 mIU/ml, they are considered protected and do not need further vaccination or testing. Those with lower levels of HBV surface antibodies would receive a single dose, and be re-tested, and if necessary receive two more doses.

As with current guidelines, health care workers who failed to respond sufficiently to the vaccine would be considered non-responders.

A post-exposure approach would involve testing the health care worker for antibodies at the same time that the source patient is tested for hepatitis B surface antigen. Health care workers with a low level of antibodies would receive the hepatitis B vaccine as well as HBV immune globulin.

There are a number of issues to consider, notes Schillie:

  • Trainees have a higher risk of bloodborne pathogen exposure than other health care workers. About 54% of needlesticks are unreported. So it would make sense to test trainees upon hire, says Schillie.
  • Some facilities, such as long-term care centers, have a high turnover of staff. Testing those employees may be logistically challenging and expensive, she says. “It might be more practical for them to use a post-exposure approach,” she says.
  • HBV vaccination of infants will eventually reduce the population of source patients who are hepatitis B surface antigen positive. The prevalence of hepatitis B in the community and among source patients may influence the decision to do routine, pre-exposure testing versus post-exposure testing.

Currently, 72% of health care facilities conduct pre-exposure testing of health care workers who were vaccinated as infants, and 20% take a post-exposure approach. About 7% give employees a challenge dose of vaccine and then test for antibodies.

“It’s optimal that institutions have an option to define their own approach,” says William Schaffner, MD, chair of the Department of Preventive Medicine at Vanderbilt University in Nashville, TN, and past president of the National Foundation for Infectious Diseases.

Meanwhile, there’s still work to be done to vaccinate older health care workers, Schaffner notes.

The U.S. Occupational Safety and Health Administration (OSHA) requires employers to offer the hepatitis B vaccine at no cost to employees. From 2005 to 2010, there were 203 cases of acute hepatitis B among health care workers that were reported to CDC. Only 19% of them reported having been vaccinated.

“We’re still not vaccinating everyone,” Schaffner notes.

Reference

  1. Centers for Disease Control and Prevention. Immunization of Healthcare Personnel – Recommendations of the Advisory Committee on Immunization Practices. MMWR 2011; 60:1-45.