Hepatitis vaccines
Hepatitis vaccines are designed to prevent infections caused by specific types of hepatitis viruses, namely hepatitis A and hepatitis B. Hepatitis is characterized by inflammation of the liver and can be caused by several viral infections, with A and B being preventable through vaccination. The vaccines for hepatitis A, such as Havrix and Vaqta, are particularly recommended for individuals in high-risk groups, including staff at day-cares and nursing homes, as well as travelers to areas where the virus is prevalent. Hepatitis B vaccines, like Engerix-B and Recombivax HB, are administered to all infants and unvaccinated children, with additional recommendations for high-risk adults, such as healthcare workers and those with certain lifestyle factors.
Vaccination schedules involve administering doses at specific intervals, and it's important to note that the series should not be restarted if missed. Additionally, licensed combination vaccines, which include components for both hepatitis A and B, are available and preferred to streamline the vaccination process. Hepatitis A primarily spreads through contaminated food and water, while hepatitis B is transmitted through contact with infected blood or bodily fluids. Overall, vaccination efforts play a critical role in controlling the spread of these highly contagious diseases, especially among vulnerable populations.
Subject Terms
Hepatitis vaccines
Definition
Hepatitis is inflammation of the liver caused by a viral infection. There are five types of hepatitis infection: A, B, C, D, and E. Not all of these types of hepatitis, however, can be prevented by vaccination.
Prevention
The types of viral hepatitis that can be prevented by a vaccine are hepatitis A and hepatitis B. Hepatitis A can be prevented by the use of Havrix or Vaqta. Hepatitis B can be prevented by the use of Engerix-B or Recombivax HB. Both A and B can be prevented by the use of Comvax, Pediarix, and Twinrix. A vaccine for hepatitis E is being tested but has not been approved by the U.S. Food and Drug Administration.
Hepatitis A vaccine is available for people in high-risk groups, such as day-care and nursing-home staff, laboratory staff, and those traveling to parts of the world where hepatitis is common. Routine childhood immunization against hepatitis A is also recommended.
Hepatitis B vaccine is given to all infants and unvaccinated children. The vaccine is available for adults at high risk, such as health care professionals, intravenous-drug users, and those who do not practice safer sex.
Requisite Dosages
Dosages are administered at intervals. No vaccine series should be restarted. Licensed combination vaccines may be used when any component of the combination is indicated and when its other component (or components) is not contraindicated. The use of licensed combination vaccines is preferred over separate injection of their equivalent component vaccines. Engerix-B or Recombivax HB should be used for the hepatitis B vaccine birth dose.
Impact
Hepatitis A and B are highly contagious. Hepatitis A is spread readily in locations with poor sanitary conditions and hepatitis B is spread through contact with the blood or body fluids of infected persons. However, hepatitis A, along with hepatitis E, are typically caused by the ingestion of contaminated food or water. Of the many persons at risk of being infected with these diseases, those who are at higher risk include people who work or travel in areas with high rates of infection and all children older than age one year.
Bibliography
Centers for Disease Control and Prevention. “Global Routine Vaccination Coverage, 2009.” MMWR: Morbidity and Mortality Weekly Report 59 (2010): 1367-1371.
Dienstag, J. L. “Hepatitis B Virus Infection.” New England Journal of Medicine 359 (2008): 1486-1500.
Jou, J. H., and A. J. Muir. “In the Clinic: Hepatitis C.” Annals of Internal Medicine 148 (2008): ITC6-1-ITC6-16.
Plotkin, Stanley A., and Walter A. Orenstein, eds. Vaccines. 5th ed. Philadelphia: Saunders/Elsevier, 2008.
Sjogren, M. H. “Hepatitis A.” In Sleisenger and Fordtran’s Gastrointestinal and Liver Disease: Pathophysiology, Diagnosis, Management, edited by Mark Feldman, Lawrence S. Friedman, and Lawrence J. Brandt. New ed. 2 vols. Philadelphia: Saunders/Elsevier, 2010.