Twinrix is a combination hepatitis vaccine approved for the prevention of hepatitis A and B in adults 18 years and older. Populations likely to benefit from this new vaccine include chronic liver disease patients and healthcare personnel. Furthermore, hepatitis A and B are the most common vaccine-preventable diseases in travelers. As a result, individuals who travel to areas such as Africa, the Caribbean, South America, Central America, the Middle East and eastern and southern Europe may also find Twinrix advantageous.
According to the World Health Organization, there are more than 350 million chronic hepatitis B virus (HBV) infections worldwide. Each year, approximately 125,000 to 200,000 Americans are infected with hepatitis A. Hepatitis B can be spread through infected blood or body fluids, sexual contact, intravenous drug use, body piercing and tattooing. Hepatitis A can spread by the "fecal-oral" route, or placing something in the mouth that has been contaminated with the stool of a person with hepatitis A.
Data was analyzed from 1,551 subjects in 11 trials following administration of three doses of Twinrix on a 0-, 1- and 6-month schedule. In these trials, 99.9% of the subjects showed a response against the hepatitis A component of Twinrix and 98.5% demonstrated a response against the hepatitis B component.
One of the 11 trials was a randomized, multicenter comparative trial conducted in the United States. In this trial, an immunogenicity analysis was performed in 533 subjects who completed the study according to protocol. Subjects received either Twinrix on a 0-, 1-, 6-month schedule or Havrix (Hepatitis A Vaccine, Inactivated) on a 0-, 6-month schedule and Engerix-B [Hepatitis B Vaccine (Recombinant)] on a 0-, 1-, 6-month schedule, given concurrently in opposite arms.
Results from the trial demonstrated that subjects receiving three doses of Twinrix had antibody responses similar to those of subjects receiving monovalent hepatitis A and B vaccines separately over the same time period. The antibody responses to the hepatitis A and B components in the Twinrix group were 99.6 and 95.1%, respectively, and 99.3 and 92.2% in the Havrix and Engerix-B group.
Twinrix was generally well tolerated in clinical trials. The most common adverse events associated with the drug included soreness at the injection site, headache and fatigue.
More information on Twinrix and other GlaxoSmithKline products can be obtained at www.gsk.com.
Individuals interested in learning more about hepatitis C can visit the following web sites: