PubMed Health⌕ Search

Biomedical subjects

Amy Morgan

Publications and source records attributed to Amy Morgan.

6 recordsLinked to original sources
PubMed2005

Immunogenicity of an investigational quadrivalent Neisseria meningitidis-diphtheria toxoid conjugate vaccine in 2-year old children.

BACKGROUND: One dose of a quadrivalent meningococcal conjugate (MC-4) vaccine elicits higher group C bactericidal responses in 2-year olds than a U.S.-licensed quadrivalent polysaccharide (MPS-4) vaccine [Granoff DM, Harris SL. Protective activity of group C anticapsular antibodies elicited in 2-year olds by an investigational quadrivalent Neisseria meningitidis-diptheria toxoid conjugate vaccine. Pediatr Infect Dis J, 2004;23:490-7]. OBJECTIVE: Assess immunogenicity and persistence of serum antibody to capsular groups A, Y and W-135 in 2-year old children immunized with MC-4 vaccine. DESIGN: Measurement of antibody responses in sera from a multicenter randomized trial comparing MC-4 and MPS-4 vaccines. RESULTS: At 1 month, the group A serum bactericidal GMT was higher in the MC-4 than the MPS-4 group (P < 0.001) but there were no significant differences at 6 months. At 6 months, the respective Y and W-135 GMTs were higher in the MC-4 group (P < 0.05) but there were no differences at 1 month. The higher W-135 bactericidal titers reflected higher antibody avidity in the MC-4 group (P < 0.0001) and avidity maturation between 1 and 6 months (P < 0.05). At 2-year post-vaccination, the proportion of MC-4 immunized children with bactericidal titers > or =1:4 (presumed to be protective) was 15.0% (group A), 32.5% (group Y) and 45% (group W-135), as compared with 2.5, 15.4 and 17.5%, respectively, in unvaccinated children (P < 0.01 for group W-135; P < 0.05 for group A, and P = 0.07 for Y). CONCLUSIONS: One dose of the MC-4 vaccine in 2-year olds elicits higher A, Y and W-135 bactericidal titers than MPS-4 vaccine. Compared with unvaccinated children, serum antibody titers remain elevated for 2 years after MC-4 vaccination. However, many vaccinated children have titers <1:4 and may require a booster dose for sustained protection.

Antibodies, Bacterial↗
PubMed2005

Persistence of group C anticapsular antibodies two to three years after immunization with an investigational quadrivalent Neisseria meningitidis-diphtheria toxoid conjugate vaccine.

BACKGROUND: An investigational quadrivalent (A, C, Y and W-135) meningococcal conjugate (MC-4) vaccine was reported to be more immunogenic in 2-year-olds than the currently licensed meningococcal polysaccharide vaccine, but persistence of serum antibody beyond 6 months after conjugate vaccination is unknown. OBJECTIVE: Determine persistence and the immunologic basis of protective activity of group C anticapsular antibodies in sera obtained 2-3 years after MC-4 vaccination. DESIGN: Group C antibody concentrations, bactericidal activity and passive protective activity were measured in sera from 48 children, ages 4-5 years, who had been immunized 2-3 years earlier with an MC-4 vaccine and from 47 children who had not been previously vaccinated. RESULTS: Serum antibody concentrations were higher in the vaccinated than the unvaccinated children (geometric means, 0.30 and 0.09 mug/mL, respectively, P < 0.0001). Bactericidal titers > or =1/4 (considered protective) were infrequent in both vaccinated and unvaccinated children (14.6 and 6.4%, respectively, P = 0.3). Passive protective activity against bacteremia in the infant rat model was more frequent in sera from vaccinated (37.5%) than sera from unvaccinated children (12.5%, P < 0.02). The proportion of sera with passive protective activity increased with increasing anticapsular antibody concentrations (P < 0.0001). INTERPRETATION: Serum group C antibody concentrations remained elevated for 2-3 years after MC-4 vaccination, and passive protective activity was more frequent in vaccinated than unvaccinated children. However, serum antibody concentrations in many vaccinated children were no longer sufficient to activate complement-mediated bacteriolysis in vitro or to confer passive protection against experimental group C disease.

Animals↗
PubMed2003

Relative effects of repetitive transcranial magnetic stimulation and electroconvulsive therapy on mood and memory: a neurocognitive risk-benefit analysis.

OBJECTIVE: Two procedures for treating major depressive disorder were compared with regard to their respective effects on mood and cognition. BACKGROUND: Fourteen patients underwent treatment with electroconvulsive therapy and 14 underwent treatment with repetitive transcranial magnetic stimulation. Patients were tested on three occasions: before initiation of treatment, at the end of treatment, and 2 weeks after the end of treatment. METHODS: Electroconvulsive therapy was applied unilaterally approximately three times per week for 2 to 4 weeks. Repetitive transcranial magnetic stimulation was applied in sessions of 1600 stimuli at 10 Hertz and 90% of motor threshold intensity to the left dorsolateral prefrontal cortex daily (Monday through Friday) for 2 consecutive weeks. RESULTS: Results indicate that electroconvulsive therapy had a more positive effect on mood than did a 2-week trial of repetitive transcranial magnetic stimulation. With regard to cognitive outcome measures, electroconvulsive therapy exerted a deleterious but transient effect on various components of memory that were no longer detected 2 weeks after the end of treatment; however, there was evidence of persistent retrograde amnesia after treatment with electroconvulsive therapy. As a group, repetitive transcranial magnetic stimulation patients experienced only a modest reduction in depression severity but there was no evidence of anterograde or retrograde memory deficits in the aftermath of treatment with repetitive transcranial magnetic stimulation. CONCLUSIONS: Findings suggest that electroconvulsive therapy is associated with transient negative cognitive side effects, most of which dissipate in the days after treatment. Deficits of this sort are not apparent after treatment with a 2-week course of repetitive transcranial magnetic stimulation.

Affect↗