Hepatitis A and B vaccine

Combined hepatitis A and B vaccine (Twinrix)
Combination of
Hepatitis A vaccine	Vaccine
Hepatitis B vaccine	Vaccine
Clinical data
Trade names	Twinrix, Ambirix, others
AHFS/ Drugs.com	FDA Professional Drug Information
License data	US  DailyMed:  Hepatitis A and hepatitis A
Pregnancy category	AU: B2
Routes of administration	Intramuscular
ATC code	J07BC20 ( WHO)
Legal status
Legal status	AU: S4 (Prescription only) UK: POM (Prescription only) [1] [2] US: ℞-only [3] EU: Rx-only [4] [5] [6]
Identifiers
CAS Number	467420-42-4 Y
ChemSpider	none
UNII	5BFC8LZ6LQ

Combined hepatitis A and B vaccine, is used to provide protection against hepatitis A and hepatitis B. ^{[3] [7]} It is given by injection into muscle. ^[8]

It is used in areas where hepatitis A and B are endemic, for travelers, people with hepatitis C or chronic liver disease, and those at high risk of sexually transmitted diseases. ^[7]

The combined vaccine is as safe and protective as if given as separate hepatitis A and B vaccines. ^[7] It is generally well-tolerated. ^[9] Common side effects are mild and include redness and pain at the injection site, where a small lump may appear. ^[8] Feeling faint or tired, or a headache may occur. ^[8] Other side effects include numbness, tingling, rash, bruising, abnormal bleeding such as from the nose or gums, weak muscle or pain. ^[8] Severe side effects are rare and include an allergic reaction and seizures. ^[8]

It is widely available. ^[7]

Administration schedule

Routine Twinrix vaccination is administered by intramuscular injection in the deltoid area using a schedule of three separate doses at 0, 1, and 6 months ([minimum intervals: 4 weeks between doses 1 and 2, 5 months between doses 2 and 3]). ^{[3] [10]} In some circumstances, an accelerated dosing schedule of 0, 7 and 21 to 30 days followed by a booster at 12 months can be used and was shown to have similar efficacy as the traditional schedule. ^[11]

Efficacy

The U.S. Centers for Disease Control and Prevention (CDC) reports that clinical trials found the following levels of protection against Hepatitis A and Hepatitis B one month after each dose: ^[12]

A: 93.8%, 98.8%, 99.9%

B: 30.8%, 78.2%, 98.5%

Availability

Twinrix is a brand manufactured by GlaxoSmithKline Biologicals. The full generic name is hepatitis A inactivated & hepatitis B (recombinant) vaccine. ^[13] Twinrix is administered over three doses. The name was created because it is a mixture of two earlier vaccines — Havrix, an inactivated-virus Hepatitis A vaccine, and Engerix-B, a recombinant Hepatitis B vaccine.^{[ citation needed]} Twinrix first entered the market in early 1997. ^[14]

In the United States, Twinrix is approved by the Food and Drug Administration (FDA) for those aged 18 and older. ^{[3] [12]} In some countries outside the United States, notably Canada and in the European Union, Twinrix is known as Twinrix Adult or Ambirix and a pediatric formulation, called Twinrix Junior or Twinrix Paediatric, is available. ^{[15] [16] [17] [18] [19] [20] [21] [22][ excessive citations]}

Society and culture

Economics

By being a combination it may reduce administrative costs and achieve a better uptake of the vaccine. ^[23]

Brand names

Brand names include Twinrix, Twinrix Junior, Twinrix paediatric, Ambirix, ^[7] and Bilive. ^[9]

References