New study confirms length of immunity conferred by Twinrix®, only combination Hepatitis A and B vaccine

31-05-2001: Results of an international, follow-up study of GlaxoSmithKline Biologicals' Twinrix® [Hepatitis A Inactivated & Hepatitis B (Recombinant) Vaccine], the world's only combination hepatitis A and B vaccine, confirm earlier findings and further demonstrate the length of immunity provided by the vaccine. The study, presented today 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 is licensed in 70 countries and was recently approved by the U.S. Food and Drug Administration for the prevention of hepatitis A and B in adults age 18 and over.

"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, M.D., 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 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 [Hepatitis A Inactivated & Hepatitis B (Recombinant) Vaccine], 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.