title: Immunogenicity of a new, low-cost recombinant hepatitis B vaccine derived from Hansenula polymorpha in adults.
abstract: BACKGROUND
  Hepatitis B virus (HBV) infection is highly prevalent world over, especially in developing countries. A new recombinant hepatitis B virus (GeneVac-B; Serum Institute of India Ltd.) vaccine is developed using Hansenula polymorpha yeast. We decided to assess the immunogenicity, and reactogenicity of this vaccine in a large adult population.
  
  
  METHODS
  Seven hundred eighty-eight adults subjects (age: 19-57 years, male:female ratio 35:1) received three 20 microg doses of a H. polymorpha-derived recombinant hepatitis B vaccine in months 0, 1, and 6. All the eligible subjects had negative baseline serum HBs Ag, and anti-HBs. The anti-HBs titer was obtained 1 month after the last dose of vaccine and was considered seroconverted if more than 1 mIU/ml, and seroprotective if more than 10 mIU/ml.
  
  
  RESULTS
  The seroprotection rate was 96% and seroconversion rate was 97%. Seroconversion and seroprotection rates declined with increasing age. The minimum geometric mean titre of anti HBs was 443 mIU/ml (95% CI 407-482). Seroprotection was 96% in age group<40 years, while the same was 91% in >40 years group (Odd's ratio-2.9100, Z value-2.6183, highly significant). No other factor like smoking, tobacco-chewing, alcohol consumption, chronic diseases, and obesity, affected the immune response. No significant adverse reactions were reported in any of the subjects.
  
  
  CONCLUSIONS
  Three standard doses of the H. polymorpha-derived recombinant HBV vaccine are highly immunogenic and safe in a predominantly male adult population. Young adults respond better with this vaccine. Because of its low cost, the vaccine may be a good choice in prevention of hepatitis B infection.
authors.affiliation: Serum Institute of India Ltd., 212/2, Hadapsar, Pune 411028, India. drpsk@seruminstitute.com
authors.forename: P S
authors.initials: PS
authors.lastname: Kulkarni
authors.forename: S K
authors.initials: SK
authors.lastname: Raut
authors.forename: P S
authors.initials: PS
authors.lastname: Patki
authors.forename: M A
authors.initials: MA
authors.lastname: Phadke
authors.forename: S S
authors.initials: SS
authors.lastname: Jadhav
authors.forename: S V
authors.initials: SV
authors.lastname: Kapre
authors.forename: S P
authors.initials: SP
authors.lastname: Dhorje
authors.forename: S R
authors.initials: SR
authors.lastname: Godse
mesh_terms: D000328:Adult; D005260:Female; D006510:Hepatitis B Antibodies / Q000097:blood; D017325:Hepatitis B Vaccines / Q000009:adverse effects / Q000191:economics / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010843:Pichia / Q000235:genetics*; D011446:Prospective Studies; D011994:Recombinant Proteins / Q000276:immunology; D014611:Vaccination; D014614:Vaccines, Synthetic / Q000276:immunology*
chemical_list: D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines; D011994:Recombinant Proteins; D014614:Vaccines, Synthetic