New Study Confirms Length of Immunity Conferred by Twinrix, Combination Hepatitis A and B Vaccine

(Innsbruck, Austria) - Results of an international, follow-up study of GlaxoSmithKline Biologicals' Twinrix confirm earlier findings and further demonstrate the length of immunity provided by the vaccine.

Twinrix is the first and only combination hepatitis A and B vaccine. The study, presented at the 7th Conference of the International Society of Travel Medicine (ISTM), evaluated the combined vaccine in adults ages 17 - 60 years old over a six-year period. Twinrix adult vaccine is licensed in 70 countries and was recently approved by the US Food and Drug Administration (FDA) for the prevention of hepatitis A and B in adults age 18 and over.

Product and Full Prescribing Information for Twinrix (PDF File)

"We saw sustained levels of immunity several years after vaccination and, based on experiences with the monovalent vaccines, we expect the levels of immunity seen in this study to be maintained for a considerable amount of time," said Pierre Van Damme, MD, PhD, professor within the Department of Epidemiology and Social Medicine at the University of Antwerp, Belgium.

Hepatitis A and B, two highly infectious liver diseases, are the most common vaccine-preventable diseases in travelers. The Centers for Disease Control (CDC) recommends hepatitis A and B vaccination for those traveling to areas with intermediate or high endemicity, including Africa, Asia (except Japan), the Caribbean, South America, Central America, the Middle East and eastern and southern Europe. According to a study published in the Journal of Travel Medicine, international travelers are not adequately informed about the risks of hepatitis B and a significant proportion unknowingly expose themselves to infection.

Long-Term Data

The safety and immunogenicity of Twinrix has been demonstrated in numerous clinical trials conducted worldwide. The study presented at the ISTM meeting, however, is the first to look at the length of immunity conferred by the vaccine over a six-year period. Investigators followed two groups of adults (ages 17- 60) who received three doses of Twinrix adult formulation, which contains 720 EL.U inactivated hepatitis A virus and 20 mg HBs antigen, on a 0-,1-, 6- month schedule. After six years, 100 percent of adults in both groups showed an antibody response to the hepatitis A component of Twinrix; and, 89 and 95 percent showed a response to the hepatitis B component.

"Twinrix is an important advance in the fight against these two infectious diseases and part of our ongoing efforts to provide the highest quality and most innovative vaccines for the prevention of disease," said John Jabara, vice president and director, GlaxoSmithKline's U.S. Vaccine Business Unit.

In clinical trials, the most common adverse events associated with Twinrix included soreness at the injection site, headache and fatigue. They were mild and self-limiting and did not last more than 48 hours.

Preventing Hepatitis A and B in Travelers and Other At-risk Groups

Despite the availability of safe and effective vaccines, hepatitis A and B are still a significant public health concern. Many people are not aware they are at risk for these diseases and up to 50 percent of persons with hepatitis A and approximately 25 percent of persons with hepatitis B have no known risk factors.

In unprotected travelers, hepatitis A occurs 10 to 100 times more than typhoid fever and 1,000 times more than cholera. It is spread through the fecal-oral route, through close person-to-person contact or by ingesting contaminated food or water.

Hepatitis B is a serious disease that can cause permanent liver damage, liver cancer and even death. It can be spread through infected blood or body fluids, sexual contact, intravenous drug use, contact sports (via cuts and scrapes), body piercing and tattooing. In some settings, hepatitis B is up to 100 times more contagious than HIV. A clear link has been demonstrated between chronic hepatitis B infection and the occurrence of hepatocellular carcinoma (primary liver cancer). In a study of adult males, vaccination against the hepatitis B virus has been shown to decrease the incidence of, and risk of, developing hepatocellular carcinoma.

For more information on hepatitis A and B prevention visit www.travelsafely.com

6/01/01

Source
GlaxoSmithKline at www.gsk.com