May be susceptible with a false positive anti-HBc. May be chronically infected and have an undetectable level of HBsAg present in the serum. They need medical monitoring and many can benefit from treatment. Hepatitis A by Harold Margolis, MD, and Linda Moyer, RN Please tell me the age ranges for adult hepatitis A vaccine formulations. Adult formulations for GlaxoSmithKline's Havrix and Merck's Vaqta hepatitis A vaccines are licensed for administration to persons 19 years of age and older.
Immunogenicity is considered to be equal to efficacy.
The second dose is necessary to assure long-term protection. If the second dose is delayed, do not start the series over again. Hepatitis B surface antigen is a marker of infectivity. Its presence indicates either acute or chronic HBV infection. Its presence indicates an immune response to HBV infection, an immune response to vaccination, or the presence of passively acquired antibody.