Biomedical subjects
M L Tepper
Publications and source records attributed to M L Tepper.
Rubella reimmunization: comparative analysis of the immunoglobulin G response to rubella virus vaccine in previously seronegative and seropositive individuals.
Rubella virus (RV)-specific immunoglobulin G (IgG) antibodies were studied in military recruits undergoing unselected immunization with live attenuated measles, mumps, and rubella virus (MMR) vaccine. Three different whole-RV enzyme immunoassays (EIAs) and an epitope-specific EIA with a synthetic peptide (BCH-178c) representing a heutralization domain on the RV E1 envelope protein were used. Before vaccination, 84.2, 87.7, and 84.5% of the subjects tested (n = 399) were found to be seropositive (> 10 IU/ml or assay equivalent) by the three whole-RV EIAs, respectively, while only 82.5% were seropositive by the BCH-178c EIA. Although prevaccination seropositivity rates were similar for the whole-RV EIAs (sensitivity, 94 to 100%), many sera considered seropositive by the whole-RV EIAs had E1 peptide EIA antibody levels of < 10 IU/ml (sensitivity, 77.4 to 80.7%). One month after vaccination, 97.8, 97.2, and 93.5% of the subjects who were followed (n = 356) were seropositive by the three whole-RV EIAs, respectively, while 89% had BCH-178c peptide-specific IgG titers of > 10 IU/ml. After vaccination, depending on the assay used, up to 20.6% of initially seropositive individuals exhibited a greater than fourfold increase in RV-specific IgG, while up to 47.3% showed a greater than twofold increase. Increased antibody titers after vaccination (seroboosting) were most frequently associated with low levels of BCH-178c peptide-specific IgG before vaccination. RV protein-specific IgG was also studied by immunoblot assays in a subset (n = 56) of individuals receiving the MMR vaccine. Of these, 89.4 and 91.1% exhibited RV protein (E1, E2, and C protein)-specific IgG before and after vaccination, respectively. Seroboosting (two- to fourfold increase in EIA titers of individuals seropositive by the whole-RV EIA before vaccination) was usually accompanied by a shift in the IgG immunoblot pattern from a single (E1) to multiple (E1-E1, E1-C, or E1-E2-C) specificities, suggesting exposure of new epitopes as a result of viral replication.
Seroprevalence of measles- and rubella-specific antibodies among military recruits, Canada, 1991.
A study of the seroprevalence of measles- and rubella-specific antibodies among military recruits in Canada in 1991 was undertaken to: 1) determine the proportion of military recruits who are measles and/or rubella seropositive when they enter the military; 2) detect general problems in the immune coverage in the young adult population; and 3) determine the proportion of measles seronegativity attributable to non-response, waning immunity or lack of exposure to either the disease or the vaccine. One initial blood sample was collected from all 399 recruits enrolled in basic training during the month of January 1991, prior to immunization with measles-mumps-rubella vaccine (MMR). Another sample was obtained from 354 of these recruits 3 to 5 weeks following this immunization. Only 18 (4.5%) recruits had negative measles-specific neutralization on the first sample. Only 12 (3.0%) recruits had negative measles-specific EIA on the first sample. All recruits had neutralization titres 40 or higher on the second sample. A total of 43 (10.8%) individuals had negative results for rubella EIA before immunization, 35 of which (81.4%) tested positive on the second sample.