title: Biodegradable delivery system for a birth control vaccine: immunogenicity studies in rats and monkeys.
abstract: OBJECTIVE
  The purpose of this study was to develop a single administration delivery system for a model birth control vaccine, in order to reduce the need for multiple injections and enhance immunogenicity.
  
  
  METHODS
  The immunogen-loaded microspheres were prepared by solvent evaporation method and characterized for loading levels, size distribution and in vitro release kinetics. The microspheres were immunized intramuscularly in wistar rats and bonnet monkeys, and the antibody response was compared to that obtained with the same total dose of the immunogen on alum given at a monthly interval.
  
  
  RESULTS
  Results indicated that a single injection of the immunogen entrapped in the microspheres generated a response comparable to that obtained by the same immunogen on alum injected at a monthly interval. The antibodies generated by the microspheres in the monkeys also had a good bioneutralization capacity indicating immunogen integrity during the microencapsulation process.
  
  
  CONCLUSIONS
  Biodegradable microspheres served as an effective delivery system for a model immunogen used in this study to reduce the need for frequent immunizations and enhance immunogenicity.
authors.affiliation: National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India.
authors.forename: M
authors.initials: M
authors.lastname: Singh
authors.forename: O
authors.initials: O
authors.lastname: Singh
authors.forename: G P
authors.initials: GP
authors.lastname: Talwar
mesh_terms: D000818:Animals; D000917:Antibody Formation; D006063:Chorionic Gonadotropin / Q000008:administration & dosage / Q000276:immunology; D003269:Contraception, Immunologic; D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems; D005260:Female; D006801:Humans; D007773:Lactates; D019344:Lactic Acid; D007986:Luteinizing Hormone / Q000008:administration & dosage / Q000276:immunology; D008255:Macaca radiata; D008297:Male; D008863:Microspheres; D009500:Neutralization Tests; D010316:Particle Size; D011091:Polyesters; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D051381:Rats; D017208:Rats, Wistar; D012756:Sheep; D013045:Species Specificity; D014612:Vaccines / Q000008:administration & dosage* / Q000276:immunology / Q000493:pharmacokinetics
chemical_list: D006063:Chorionic Gonadotropin; D003692:Delayed-Action Preparations; D007773:Lactates; D011091:Polyesters; D011108:Polymers; D014612:Vaccines; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C033616:poly(lactide); D007986:Luteinizing Hormone