Vaccine
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Comparative Study
A benefit-cost analysis of two-dose measles immunization in Canada.
In 1992, because of the limitations of the one-dose measles immunization program, the National Advisory Committee on Immunization (NACI) recommended a two-dose measles immunization program to eliminate measles. More recently, NACI recommended also a special catch-up program to prevent predicted measles outbreaks and to achieve an earlier elimination of measles. ⋯ The resulting benefit: cost ratios vary between 2.61:1 and 4.31:1 depending on the strategy used and the age of the children targeted. Given the parameters established for this analysis, the benefits of a second-dose vaccination program against measles far outweight the costs of such a program under all scenarios.
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Comparative Study Clinical Trial Controlled Clinical Trial
Antibody titers eight months after three doses of a five-valent pneumococcal conjugate vaccine in HIV and non-HIV-infected children less than two years of age.
The objective of this study was to examine vaccine type-specific antibody titers eight months after a five-valent pneumococcal conjugate vaccine (PCV) in human immunodeficiency virus (HIV) and non-HIV-infected children under two years of age. Sixteen HIV-infected and 14 non-HIV-infected children under two years of age, and of similar age, race and sex distribution, received three doses (separated by two months each) of a five-valent oligosaccharide PCV (types 6B, 14, 18C, 19F, and 23F separately coupled to diphtheria CRM197). An additional 11 non-HIV-infected children, of similar demographic distribution to the PCV groups, received three doses of saline placebo. sera were collected just prior to, and at one and eight months after the three study drug doses. ⋯ At the eight month post-PCV series blood draw, there were no significant differences in the GMTs, the percent drop in titers, or proportion of titers > 1.0 microgram ml-1 between the five HIV-infected children who had advanced (CDC class: N3, A3, B2-3, C1-3) compared to the 11 children with mild (CDC class: N1-2, A1-2, B1) HIV disease at the time of their first PCV dose. Eight months after the PCV series, the proportion of titers (combined all five serotypes) > 1.0 microgram ml-1 was slightly, but significantly, lower for HIV-infected subjects (46%) compared to non-HIV-infected subjects (62%) (p < 0.05). These data are helpful in describing the kinetics of antibody responses to pneumococcal conjugate vaccines in both HIV and non-HIV-infected young children.
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Randomized Controlled Trial Comparative Study Clinical Trial
Safety and characterization of the immune response engendered by two combined measles, mumps and rubella vaccines.
We performed a randomized trial to compare the safety and immunogenicity of two combined measles, mumps and rubella vaccines in healthy children 14-24 months of age. Triviraten Berna Vaccine (Swiss Serum and Vaccine Institute), contains the Edmonston Zagreb 19 strain of measles virus, the Rubini mumps virus strain and the Wistar RA 27/3 rubella strain while MMR-Vax (Merck, Sharp & Dohme, West Point, PA) contains the Enders attenuated Edmonston measles strain, the Jeryl Lynn mumps strain and the Wistar RA 27/3 rubella strain. Immunization with Triviraten Berna was associated with a significantly lower incidence of swelling and redness at the injection site in addition to a reduced rate of fever compared with MMR-Vax. ⋯ While few subjects mounted a humoral antibody response to measles, most likely due to elevated baseline titers, there was a marked lymphoproliferative response. Anti-mumps virus ELISA antibody titers were higher both at baseline and after reimmunization in subjects who received MMR-Vax for primary immunization. However, there was no difference in either neutralizing titer or proliferative response in subjects primed with MMR-Vax or Triviraten Berna either before or after reimmunization.
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A two-dose vaccination program against measles, mumps, and rubella (MMR) viruses was started in Finland in 1982. In this program the trivalent MMR-II vaccine (MSD, USA) was offered to children at the ages of 14-18 months and 6 years followed by revaccination 4-5 years later. The vaccination coverage has been high (97%) and MMR infections have practically been eliminated in the Finnish population. ⋯ The mean antibody titer was significantly (p < 0.05) higher 4 years after the second MMR vaccination when compared with the corresponding time point after the first vaccination. In 6-year-old seronegative vaccinees the increase and decay of anti-mumps virus antibodies after the first MMR vaccination was similar to that seen in the group of younger vaccinees. A two-dose MMR vaccination protocol resulted in a high mumps immunity level in the vaccinated population.
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Comparative Study
Immunogenicity of rabies vaccines used during an urban epizootic of rabies in Mexico.
From 1 July 1987 to 31 December 1988, 30% of 247 rabid dogs in Hermosillo, Mexico had a positive history of rabies vaccination. Serosurveys suggested that inactivated suckling mouse brain vaccine (INACT-SMBV) and inactivated tissue culture vaccine (INACT-TC) used before and during the epizootic were poor immunogens. ⋯ Rabies vaccines should be evaluated periodically by measuring antibody responses in animals. In some circumstances, minimum seroconversion rates and antibody titres in vaccinated animals may be better measures of immunogenicity than relative potency.