Hepatitis B virus surface protein

An isolated variant hepatitis B surface antigen comprising an amino acid sequence wherein mutations from hepatitis B wild type ayw2 strain appear as follows:

• at position 103 isoleucine is present instead of methionine, at position 118 lysine is present instead of threonine, at position 120 glutamine is present instead of proline, at position 175 serine is present instead of leucine, and at position 213 seine is present instead of leucine, as shown in SEQ.ID.NO.:7.