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)
Three Doses of Hepatitis A Vaccine in Patients With Immunomodulating Drugs [Recruiting]
Hepatitis A vaccine is the most frequently used traveler's vaccine, yet data on its ability
to induce protective immunity in immunosuppressed travelers are scarce. The investigators
assess the hepatitis A virus (HAV) antibody response in patients with rheumatoid arthritis
(RA) treated with Tumor Necrosis Factor (TNF) - inhibitors and/or methotrexate (Mtx).
In a previous study, 2 doses were not considered effective and there is therefore need for a
study with an additional dose
The Immunogenicity and Safety of 60mcg/30mcg Recombinant Hepatitis B Vaccines in People Who Failed to Respond to Routine Administration of Hepatitis B Vaccines [Completed]
This study is an expanded Phase 2/Phase 3 clinical trial base on the safety data obtained
from the phase 1 clinical trial. The purpose of this study is to further evaluate the
immunogenicity and safety of 60mcg/30mcg recombinant hepatitis B vaccines in people aged 16
and older who failed to respond to routine administration of 10mcg recombinant hepatitis B
vaccines and to explore the optimizing immunizing dose and immune procedure.
Comparison of Immunization Schedules of Inactivated Hepatitis A Vaccine and Combined Hepatitis A and Hepatitis B Vaccine [Completed]
Immunogenicity and Interchangeability of Two Inactivated Hepatitis A Vaccines [Completed]
This is a randomized, double-blind clinical trial of two inactivated hepatitis A vaccines in
healthy children, immunogenicity and interchangeability of the two inactivated hepatitis A
vaccines were evaluated.
HIV and Hepatitis Care Coordination in Methadone Treatment [Completed]
This randomized clinical trial will examine the effectiveness of a strategy of HIV and
Hepatitis Care Coordination (HCC) consisting of testing, education, counseling and
vaccination for methadone maintenance patients compared with standard Testing, Education,
and Counseling (TEC).