Summary of CDC Recommendations on Hepatitis B Vaccinations
Hepatitis B
Hepatitis B virus (HBV) infection is the major infectious hazard for health-care personnel. During 1993, an estimated 1,450 workers became infected through exposure to blood and serum-derived body fluids, a 90% decrease from the number estimated to have been thus infected during 1985 (18-20). Data indicate that 5%-10% of HBV-infected workers become chronically infected. Persons with chronic HBV infection are at risk for chronic liver disease (i.e., chronic active hepatitis, cirrhosis, and primary hepatocellular carcinoma) and are potentially infectious throughout their lifetimes. An estimated 100-200 health-care personnel have died annually during the past decade because of the chronic consequences of HBV infection (CDC, unpublished data).
The risk for acquiring HBV infection from occupational exposures is dependent on the frequency of percutaneous and permucosal exposures to blood or body fluids containing blood (21-25). Depending on the tasks he or she performs, any health-care or public safety worker may be at high risk for HBV exposure. Workers performing tasks involving exposure to blood or blood-contaminated body fluids should be vaccinated. For public safety workers whose exposure to blood is infrequent, timely postexposure prophylaxis may be considered, rather than routine preexposure vaccination.
In 1987, the Departments of Labor and Health and Human Services issued a Joint Advisory Notice regarding protection of employees against workplace exposure to HBV and human immunodeficiency virus (HIV), and began the process of rulemaking to regulate such exposures (26). The Federal Standard issued in December, 1991 under the Occupational Safety and Health Act mandates that hepatitis B vaccine be made available at the employer's expense to all health-care personnel who are occupationally exposed to blood or other potentially infectious materials (27). Occupational exposure is defined as "...reasonably anticipated skin, eye, mucous membrane, or parenteral contact with blood or other potentially infectious materials that may result from the performance of an employee's duties (27)." The Occupational Safety and Health Administration (OSHA) follows current ACIP recommendations for its immunization practices requirements (e.g., preexposure and postexposure antibody testing). These regulations have accelerated and broadened the use of hepatitis B vaccine in HCWs and have ensured maximal efforts to prevent this occupational disease (23).
Prevaccination serologic screening for prior infection is not indicated for persons being vaccinated because of occupational risk. Postvaccination testing for antibody to hepatitis B surface antigen (anti-HBs) response is indicated for HCWs who have blood or patient contact and are at ongoing risk for injuries with sharp instruments or needlesticks (e.g., physicians, nurses, dentists, phlebotomists, medical technicians and students of these professions). Knowledge of antibody response aids in determining appropriate postexposure prophylaxis.
Vaccine-induced antibodies to HBV decline gradually over time, and less than or equal to 60% of persons who initially respond to vaccination will lose detectable antibodies over 12 years (28; CDC, unpublished data). Studies among adults have demonstrated that, despite declining serum levels of antibody, vaccine-induced immunity continues to prevent clinical disease or detectable viremic HBV infection (29). Therefore, booster doses are not considered necessary (1). Periodic serologic testing to monitor antibody concentrations after completion of the three-dose series is not recommended. The possible need for booster doses will be assessed as additional data become available.
Asymptomatic HBV infections have been detected in vaccinated persons by means of serologic testing for antibody to hepatitis B core antigen (anti-HBc) (1). However, these infections also provide lasting immunity and are not associated with HBV-related chronic liver disease.
Immunization Is Strongly Recommended . . .
Hepatitis B
Any HCW who performs tasks involving contact with blood, blood-contaminated
body fluids, other body fluids, or sharps should be vaccinated. Hepatitis B
vaccine should always be administered by the intramuscular route in the deltoid
muscle with a needle 1-1.5 inches long.
Among health-care professionals,
risks for percutaneous and permucosal exposures to blood vary during the
training and working career of each person but are often highest during the
professional training period. Therefore, vaccination should be completed during
training in schools of medicine, dentistry, nursing, laboratory technology, and
other allied health professions, before trainees have contact with blood. In
addition, the OSHA Federal Standard requires employers to offer hepatitis B
vaccine free of charge to employees who are occupationally exposed to blood or
other potentially infectious materials (27).
Prevaccination serologic screening for previous infection is not indicated for persons being vaccinated because of occupational risk unless the hospital or health-care organization considers screening cost-effective. Postexposure prophylaxis with hepatitis B immune globulin (HBIG) (passive immunization) and/or vaccine (active immunization) should be used when indicated (e.g., after percutaneous or mucous membrane exposure to blood known or suspected to be HBsAg-positive.
Needlestick or other percutaneous exposures of unvaccinated persons should lead to initiation of the hepatitis B vaccine series. Postexposure prophylaxis should be considered for any percutaneous, ocular, or mucous membrane exposure to blood in the workplace and is determined by the HBsAg status of the source and the vaccination and vaccine-response status of the exposed person(1,18).
If the source of exposure is HBsAg-positive and the exposed person is unvaccinated, HBIG also should be administered as soon as possible after exposure (preferably within 24 hours) and the vaccine series started. The effectiveness of HBIG when administered greater than 7 days after percutaneous or permucosal exposures is unknown. If the exposed person had an adequate antibody response (greater than or equal to 10 mIU/mL) documented after vaccination, no testing or treatment is needed, although administration of a booster dose of vaccine can be considered.
One to 2 months after completion of the 3-dose vaccination series, HCWs who have contact with patients or blood and are at ongoing risk for injuries with sharp instruments or needlesticks should be tested for antibody to hepatitis B surface antigen (anti-HBs). Persons who do not respond to the primary vaccine series should complete a second three-dose vaccine series or be evaluated to determine if they are HBsAg-positive. Revaccinated persons should be retested at the completion of the second vaccine series. Persons who prove to be HBsAg-positive should be counseled accordingly (1,16,121,173). Primary non-responders to vaccination who are HBsAg-negative should be considered susceptible to HBV infection and should be counseled regarding precautions to prevent HBV infection and the need to obtain HBIG prophylaxis for any known or probable parenteral exposure to HBsAg-positive blood. Booster doses of hepatitis B vaccine are not considered necessary, and periodic serologic testing to monitor antibody concentrations after completion of the vaccine series is not recommended.