VAQTA® (Hepatitis A Vaccine, Inactivated) is an inactivated whole virus vaccine derived from hepatitis A virus grown in cell culture in human MRC-5 diploid fibroblasts and has been shown to induce antibody to hepatitis A virus protein. 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, formalin inactivated, and then adsorbed onto amorphous aluminium hydroxyphosphate sulfate adjuvant. One millilitre of the vaccine contains approximately 50 units (U) of hepatitis A antigen, which is highly purified and is formulated without a preservative. Within the limits of current assay variability, the 50 U dose of VAQTA contains less than 0.1 µg of non-viral protein, less than 4 x 10-6 µg of DNA, less than 10-4 µg of bovine albumin and less than 0.8 µg of formaldehyde. Other process chemical residuals (including neomycin) are less than 10 parts per billion (ppb). The manufacture of this product includes exposure to bovine related materials. No evidence exists that any case of vCJD (considered to be the human form of bovine spongiform encephalopathy) has resulted from the administration of any vaccine product.