Hepatitis A Vaccine. Hepatitis A vaccination is recommended for all children at age 1 year, for persons who are at increased risk for infection, for persons who are at increased risk 157 for complications from hepatitis A, and for any person wishing to obtain immunity. In the United States, two single- antigen inactivated hepatitis A vaccines are commercially available, Havrix and Vaqta. Both vaccines are licensed for persons 12 months of age and older. A combination inactivated vaccine, Twinrix, which contains both hepatitis A virus (HAV) and HBV antigens, is also available for use in persons aged 18 years and older. These vaccines should be administered by intramuscular injection in the deltoid muscle or lateral thigh, with a needle length appropriate for the person's age and size. Hepatitis B Vaccine. 7 In 2013 an estimated 19,764 persons in the United States were newly infected with HBV; rates are highest among adults, particularly men aged 25 to 44 years. An estimated 700,000 to 1.4 million persons in the United States have chronic HBV infection. 24 In primary care settings, targeting vaccination to persons at risk is an efficient approach to prevention of HBV infection. 25 The rate of new HBV infections has declined by approximately 82% since 1991, when a national strategy to eliminate HBV infection was implemented in the United States; in 2013 the overall incidence of reported acute hepatitis B was 0.9 cases per 100,000 population. 24 Populations that are at increased risk of becoming infecting with HBV include infants born to infected mothers, sex partners of infected persons, health care and public safety workers at risk for occupational exposure to blood or blood- contaminated body fluids, travelers to countries with intermediate or high prevalence of HBV infection, hemodialysis patients, and men who have sex with men. 24 Two single-antigen vaccines and three combination vaccines are currently licensed in the United States. 24 Of the three licensed combination vaccines, one (Twinrix) is used for vaccination of persons 18 years or older with risk factors for both hepatitis A and hepatitis B; it contains recombinant hepatitis B surface antigen (HBsAg) and inactivated HAV. 24 The dose of the hepatitis A component in the combined vaccine is lower than that in the single-antigen hepatitis A vaccine, allowing it to be administered in a three-dose schedule instead of the two-dose schedule used for the single- antigen vaccine. An immune response against hepatitis A and B was observed and maintained over the long term in a high percentage of vaccines. 26 The hepatitis B three-dose vaccine series administered intramuscularly at 0, 1, and 6 months produces a protective antibody response in approximately 30% to 55% of healthy adults 40 years of age and younger after the first dose, 75% after the second dose, and more than 90% after the third dose.
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- Summer '16
- Hepatitis B vaccine, HPV vaccine, Hepatitis A Vaccine