FDA Approves Expanded Age Indication for Hepatitis A Vaccine

WHITEHOUSE STATION, N.J. -- Merck & Co., Inc. announced that the U.S. Food and Drug Administration (FDA) has approved VAQTA® (hepatitis A vaccine, inactivated) for use in children 12 months of age and older. VAQTA is now the first and only hepatitis A vaccine that can be used in children as young as 12 months of age. Previously, VAQTA was approved for use in people two years of age and older.

"Surveillance data have shown that young children often transmit hepatitis A in the United States, but since they do not typically show symptoms, they unknowingly pass the infection on to older siblings and parents who can become very ill from hepatitis A," said Fernando Guerra, MD, MPH, director of health, San Antonio Metropolitan Health District. "The expanded age indication for VAQTA is good news for parents, doctors and the public health community because it means we can help protect children against hepatitis A earlier in life."

Study Supports Use of VAQTA Starting at 12 Months of Age
The younger age indication for VAQTA is supported by the results of an open-label study of children with no evidence of hepatitis A infection. The study was designed to investigate the immunogenicity and safety of VAQTA in this age group when it was administered with and without other routinely used vaccines given at the same age.

In this study of 617 children 12-23 months of age, 343 children were evaluated for indicators of an immune response to VAQTA after the second dose of a two dose series. Of these children (n=343), 100 percent developed protective immune responses. The study also showed that VAQTA may be given concomitantly with M-M-R II® (Measles, Mumps and Rubella Virus Vaccine Live), another Merck vaccine. Data on concomitant use with other routinely recommended childhood vaccines are limited.

In combined clinical trials involving healthy children 12-23 months of age, (n=706) who received one or more doses (~25U) of VAQTA alone or in combination with other routinely recommended pediatric vaccines, the most commonly reported complaints (>2 percent of injections) after one or both of the doses of VAQTA were localized injection-site reactions (pain/tenderness/soreness), fever, diarrhea, vomiting, irritability, upper respiratory infection, rhinorrhea, cough, rash and otitis media.

Hepatitis A Still Prevalent in United States
Hepatitis A is a contagious disease caused by a virus that can result in an infection of the liver. Symptoms include jaundice, fever, abdominal pain, dark urine and nausea. Signs and symptoms usually last less than two months, although 10-15 percent of symptomatic persons have prolonged or relapsing disease lasting up to six months. The virus is transmitted most frequently by the fecal-oral route through person-to-person contact and/or ingestion of contaminated food or water. The source of a case of hepatitis A is unknown in nearly half of all cases. There is no specific treatment available for hepatitis A.

According to a Center for Disease Control and Prevention (CDC) report issued in September of 2004, there were 8,795 reported cases of hepatitis A in 2002, down from an average of 28,000 cases per year from 1987 through 1997, before hepatitis A vaccines became widely used. Approximately 25 percent of hepatitis A cases reported in 2002 required hospitalization and approximately one in 200 cases resulted in death.

About VAQTA
VAQTA is indicated for active immunization against disease caused by hepatitis A virus in persons 12 months of age and older. Primary immunization should be given at least two weeks prior to expected exposure to hepatitis A virus (HAV).

Individuals 12 months through 18 years of age should receive a single 0.5 mL (~25U) dose of vaccine at elected date and a booster dose of 0.5 mL (~25U) six to 18 months later. Adults >19 years of age should receive a single 1.0 mL (~50U) dose of vaccine at elected date and a booster dose of 1.0 mL (~50U) six to 18 months later.

VAQTA is contraindicated in individuals who are hypersensitive to any component of the vaccine. Hepatitis A vaccine should not be administered to persons with a history of a severe reaction to a prior dose of hepatitis A vaccine or to a vaccine component. As with any vaccine, vaccination with VAQTA may not result in a protective response in all people.

In combined clinical trials involving healthy children 12-23 months of age and children and adolescents two to 18 years of age, the most commonly reported complaints (>2 percent of injections) in one or both of these groups were localized injection-site reactions (pain/tenderness/soreness, warmth, erythema, swelling), fever, diarrhea, vomiting, irritability, upper respiratory infection, rhinorrhea, cough, rash, otitis media, and headache.

In combined clinical trials involving healthy adults 19 years of age and older, the most commonly reported complaints (>2 percent of injections) were localized injection-site reactions (tenderness, pain, warmth, swelling, and erythema), headache, asthenia/fatigue, fever, pharyngitis, upper respiratory infection, diarrhea, and nausea. As with any vaccine, there is the possibility that use of VAQTA in very large populations might reveal adverse experiences not observed in clinical trials.

VAQTA is an inactivated whole virus vaccine and is the product of more than 20 years of research by Merck scientists.

About Merck
Merck & Co., Inc. is a global research-driven pharmaceutical company dedicated to putting patients first. Established in 1891, Merck discovers, develops, manufactures and markets vaccines and medicines in more than 20 therapeutic categories.

Source: Merck & Company., Inc.