VAQTA [Hepatitis A Vaccine, Inactivated] is an inactivated whole virus vaccine derived from hepatitis A virus (HAV) grown in cell culture in human MRC-5 diploid fibroblasts. It contains inactivated virus of a strain which was originally derived by further serial passage of a proven attenuated strain. The virus is grown, harvested, purified by a combination of physical and high performance liquid chromatographic techniques developed at the Merck Research Laboratories, formalin inactivated, and then adsorbed onto amorphous aluminum hydroxyphosphate sulfate. One milliliter of the vaccine contains approximately 50 units (U) of hepatitis A virus antigen, which is purified and formulated without a preservative. Within the limits of current assay variability, the 50U dose of VAQTA contains less than 0.1 mcg of a non-viral protein, less than 4 × 10-6 mcg of DNA, less than 10-4 mcg of bovine albumin, and less than 0.8 mcg of formaldehyde. Other process chemical residuals are less than 10 parts per billion (ppb).
VAQTA is indicated for active pre-exposure prophylaxis against disease caused by hepatitis A virus in persons 2 years of age and older. Primary immunization should be given at least 2 weeks prior to expected exposure to HAV.
Published Studies Related to Vaqta (Hepatitis A Vaccine)
Hepatitis B vaccination in HIV-infected youth: a randomized trial of three regimens. [2011.04]
BACKGROUND: HIV-infected youth are at risk of hepatitis B infection and should be vaccinated. Previous reports suggest reduced response to standard hepatitis B vaccine regimens... CONCLUSIONS: In HIV-infected youth, a three-dose vaccination regimen with Engerix B, 40 mug, or Twinrix and higher baseline CD4+ T-cell counts were independently associated with improved vaccine response.
Comparative immunogenicity of two vaccination schedules of a combined hepatitis A and B vaccine in healthy volunteers. [2011.04]
In 1996, a combined vaccine against both hepatitis A and B was licensed and commercialized and has been recommended for healthcare personnel in Belgium. This study compares the immunogenicity against hepatitis B virus (HBV) and safety of two vaccination schedules (0-1-12 months and 0-1-6 months) with this vaccine...
Antibody persistence and immune memory 4 years post-vaccination with combined hepatitis A and B vaccine in adults aged over 40 years. [2011.03]
Persistence of immune response was assessed in adults aged >40 years (N = 596) following primary vaccination with combined hepatitis A/B vaccine or concomitant monovalent hepatitis A and B vaccines. Anti-hepatitis A virus antibody responses persisted for at least 4 years regardless of the vaccine used, with anti-hepatitis B surface antibody responses higher and more sustained in subjects who received the combined hepatitis A/B vaccine.
The use of dried blood spots for assessing antibody response to hepatitis A virus after natural infection and vaccination. [2011.02]
During recent years, vaccination against hepatitis A has been implemented in several countries. It is expected that the increase in mass vaccination against hepatitis A will eventually result in a decreased prevalence of anti-HAV antibodies in the general population... The results showed that DBS samples can be used for the detection of anti-HAV antibodies both after natural infection or vaccination.
A randomized clinical trial of immunization with combined hepatitis A and B versus hepatitis B alone for hepatitis B seroprotection in hemodialysis patients. [2010.10]
BACKGROUND: The Centers for Disease Control and Prevention recommend immunizing susceptible high-risk groups, such as hemodialysis patients, against hepatitis B virus. However, hemodialysis patients may not develop seroprotective antibodies despite receiving high doses of the vaccine. Recent reports indicate that combined vaccination against hepatitis B and hepatitis A viruses may improve the immunogenicity of hepatitis B vaccine in healthy individuals, but the effectiveness of this strategy in hemodialysis patients is unknown... CONCLUSION: Vaccination of hemodialysis patients with a combined hepatitis A and hepatitis B regimen resulted in a statistically significant and clinically important improvement in seroprotection against hepatitis B virus compared with hepatitis B monovalent vaccine. Copyright (c) 2010 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.
Clinical Trials Related to Vaqta (Hepatitis A Vaccine)
Hepatitis A Vaccine, Inactivated and Measles, Mumps, Rubella and Varicella [Oka/Merck] Virus Vaccine Live Safety Study [Completed]
Two doses each of Hepatitis A Vaccine, Inactivated and Measles, Mumps, Rubella and Varicella
[Oka/Merck] Virus Vaccine Live will be given concomitantly or non-concomitantly. Safety
data will be collected following each vaccination.
Phase III, Open, Comparative Study in Healthy Adults Aged 18-50 Years Administered With Hepatyrix or Havrix + Typherix or Tiphim Vi, to Compare Reactogenicity and Immunogenicity. [Active, not recruiting]
To evaluate the immunogenicity, reactogenicity and safety of Hepatyrix when compared to the
concomitant administration of Typherix and Havrix, and when compared to the administration of
monovalent vaccines, Havrix or Typhim Vi. Furthermore, the study will evaluate the
persistence of anti-Vi and anti-HAV antibodies up to 36 months after administration of the
first dose of the study vaccine.
Surveillance Study to Determine the Trends in Acute Hepatitis A Among Panamanian Children [Recruiting]
Immune Response & Safety of a Hepatitis A Vaccine Given Together With a Pneumococcal Vaccine in Healthy Children 15 m of Age [Completed]
This is a study to evaluate the immunogenicity and safety of GSK Biologicals 2-dose
inactivated hepatitis A vaccine when administered with a pneumococcal conjugate vaccine in
children as young as 15 months of age
Concomitant Use of Hepatitis A Vaccine With Measles, Mumps, Rubella, and Varicella Vaccine and Pneumococcal 7-Valent Conjugate Vaccine in Healthy 12-Month Old Children [Active, not recruiting]
Hepatitis A vaccine will be given either alone or together with measles, mumps, rubella, and
varicella vaccine and pneumococcal 7-valent conjugate vaccine at the first dose and together
with measles, mumps, rubella, and varicella [Oka/Merck] virus vaccine at the second dose.
Immunogenicity and safety data will be collected after each dose of vaccine.
Page last updated: 2011-12-09