IMMUNIZATION, HEPATITIS A

When immediate protection against hepatitis A (infectious hepatitis) is needed, immunoglobulins are used. Protection is effective only if given within 2 weeks of exposure and lasts but 2-4 months. Immunoglobulins can be used to protect household contacts of someone with acute viral hepatitis and travelers to regions with poor sanitation and high hepatitis A rates, when the traveler has to depart sooner than the vaccines can take effect (about 2 weeks). Travelers can receive the immunoglobulin and vaccine simultaneously and be protected immediately and for longer term. When immediate protection is not needed, hepatitis A vaccines are considered for individuals in high-risk settings, including frequent world travelers, sexually active individuals with multiple partners, homosexual men, individuals using illicit drugs, employees of daycare centers, and certain health care workers, and sewage workers. Two hepatitis A vaccines called HAVRIX and VAQTA are commercially available in the U.S. Both are highly effective and provide protection even after only one dose. Two doses are recommended for adults and 3 doses for children (under 18 years of age) to provide prolonged protection.