Recombinant Protein Vaccines

The hepatitis B virus (HBV) vaccine is the major example of a recombinant protein vaccine in current use and the first vaccine produced by recombinant DNA technology. The vaccine contains a highly purified form of recombinant HBsAg, encoded by a single gene and expressed in yeast. As with most subunit vaccines, it requires multiple boosters but has proven to be highly efficacious. Humans are the only host for HBV.
Prior to the recombinant vaccine becoming available, the only available source of HBV antigen was blood from infected individuals, a risky procedure for those involved. This is a highly infectious virus and the number of cases of infection prevented and indeed hepatic cancer cases
prevented is incalculable. WHO estimates suggest that up to 2 billion of the global population are infected with HBV, with 360 million chronically infected. Due to the large scale of HBV infection, the vaccine has been introduced into infant immunisation programmes in over 160 countries. In the UK, the vaccine is retained for use in high-risk groups, in particular healthcare workers and appropriate laboratory staff.
Recently, two recombinant protein vaccines have been developed for human papilloma virus (HPV), the primary cause of cervical cancer and genital warts. These vaccines combine HPV proteins in self-associating virus-like particles. The vaccines are Gardisal (Merck), which contains proteins from HPV 16, 18, 6 and 11 produced by recombinant yeast technology, and Cervarix (GlaxoSmithKline), which contains proteins from HPV 16 and 18 produced by recombinant baculovirus technology.