title: The effect of decreasing amounts of live virus, while antigen content remains constant, on immunogenicity of Oka/Merck varicella vaccine.
abstract: The purpose of the study was to establish the minimum immunizing dose of stored Oka/Merck varicella vaccine and mimic effects of prolonged storage of vaccine at freezer temperatures. Ninety children were randomized to one of three groups: group A (1770 pfu/dose), group B (400-500 pfu/dose), or group C (80-160 pfu/dose). Seroconversion rates for groups A-C were 97%, 96%, and 92%, respectively. Group A and B vaccinees had higher antibody titers at 1 year than did group C subjects (P = .01). The difference between groups B and C approached significance (P = .058). At 1 year after immunization, 73%, 83%, and 80% in groups A-C, respectively, demonstrated cell-mediated responses. Since freshly reconstituted vaccine contains 1770 pfu/dose, vaccine failure from loss of potency is unlikely if vaccine is stored properly and administered promptly after reconstitution.
authors.affiliation: Division of Allergy, Immunology, and Infectious Diseases, Joseph Stokes Jr. Research Institute, Children's Hospital of Philadelphia, PA 19104.
authors.forename: B
authors.initials: B
authors.lastname: Watson
authors.forename: S
authors.initials: S
authors.lastname: Piercy
authors.forename: D
authors.initials: D
authors.lastname: Soppas
authors.forename: K
authors.initials: K
authors.lastname: Browngoehl
authors.forename: M
authors.initials: M
authors.lastname: Warner
authors.forename: K
authors.initials: K
authors.lastname: Isganitis
authors.forename: C J
authors.initials: CJ
authors.lastname: White
authors.forename: B
authors.initials: B
authors.lastname: Kuter
authors.forename: J
authors.initials: J
authors.lastname: Chua
authors.forename: S
authors.initials: S
authors.lastname: Starr
mesh_terms: D000914:Antibodies, Viral / Q000096:biosynthesis; D000956:Antigens, Viral / Q000276:immunology*; D002644:Chickenpox / Q000517:prevention & control*; D019433:Chickenpox Vaccine; D002648:Child; D002675:Child, Preschool; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D005615:Freezing; D014645:Herpesvirus 3, Human / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation; D008297:Male; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology / Q000627:therapeutic use; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology* / Q000627:therapeutic use
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D019433:Chickenpox Vaccine; D014613:Vaccines, Attenuated; D014765:Viral Vaccines