Percentages of CD8 or CD4 T-cells expressing IFN-γ, CD69 or both markers in negative control cultures were subtracted from those in stimulated cultures. A net value of >0.1% was considered positive (Table 5). Memory cell assay at 9 months: Only samples from group 2 infants were tested. In the majority of samples IFN-γ and CD69 responses to the nucleoprotein peptide pool were detectable in CD4 but not in CD8 T-cells. Effector cell assay at 9.5 months of age: A similar but low proportion of CD4 and CD8 T-cells from the two groups showed a positive IFN-γ response after stimulation with E-D virus. There was concurrence of CD4 and CD8 IFN-γ responses in
6 of 7 samples. Expression of CD69 was detected more often in CD8 than CD4 T-cells. Memory cell assay at 18 months: After stimulation with EZ virus IL-2 expression was detectable in less than half of the samples and very few expressed IFN-γ. There were no significant differences between cell types selleck chemicals llc and little concurrence within the positive samples. Measles antibody protects against infection but Crizotinib its role in limiting viral multiplication and severity of disease is less clear . Although an arbitrary protective level of measles antibody has
been ascribed, in an outbreak of measles in Senegal half of the antibody negative vaccinated children did not develop measles when exposed . In vaccinated macaques a rapid amnestic antibody response follows measles infection which coupled with a boost in cell mediated immunity limits viral replication and aborts disease . With the assumption that a booster dose of vaccine mimics infection or exposure, we examined both antibody and cell mediated responses shortly after re-vaccination. Our study is the first to provide detailed knowledge of the early antibody response to
a booster dose of measles vaccine following 3-mercaptopyruvate sulfurtransferase either vaccine schedule. A standard dose of E-Z vaccine in 4 month old infants raised protective levels of antibody in the majority of the children by 9 months of age. After either one or two booster doses of vaccine antibody concentrations rose dramatically within 2 weeks and faded slowly with time. Maternal antibody, possibly by neutralising the live vaccine and altering antigen processing , depressed both primary and secondary antibody responses. The impact faded by 36 months of age and did not influence responses to further vaccination. The booster responses were independent of antibody at the time of vaccination suggesting that even if antibody concentrations are low a rapid response in conjunction with cellular immune responses will limit disease and lower transmission on subsequent measles exposure . However concentrations of antibody following a boost decayed quicker in group 2 children. They may be more susceptible to subclinical infections  though this event is unlikely to result in the further spread of measles .