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Geometric Mean Titers (geometric + mean_titer)
Selected AbstractsA Two Year Follow-Up Study of Common Virus Infections in Hemodialysis Patients in TaiwanARTIFICIAL ORGANS, Issue 10 2002Tze Wah Kao Abstract: The study was designed to determine whether hemodialysis patients in Taiwan had a different antibody response to common virus infections compared to the normal population. Serum samples from 18 hemodialysis patients and 21 healthy volunteers were obtained every 3 months for 2 years. Geometric mean titers (GMTs) of immunoglobulin G (IgG) antibodies to cytomegalovirus (CMV), herpes simplex virus (HSV), varicella-zoster virus (VZV), Epstein-Barr virus (EBV), as well as Type A and Type B influenza viruses (Inf. A, Inf. B) were compared between the patient and the control groups. The prevalence rates and the rates of recurrent infection were similar in both groups. However, the patient group had a higher percentage of persons having persistent EBV and CMV infections (p < 0.05) and also higher GMTs of antibodies nearly the whole year round, especially significant in September and December (p < 0.05). In patients with hepatitis C, their GMTs of EBV, VZV, Inf. A, and Inf. B were higher than those without (p < 0.05). [source] Safety and Immunogenicity Profile of the Concomitant Administration of ZOSTAVAX and Inactivated Influenza Vaccine in Adults Aged 50 and OlderJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 10 2007Boris Kerzner MD OBJECTIVES: To evaluate the safety and immunogenicity of ZOSTAVAX administered concomitantly with inactivated influenza vaccine or sequentially in adults aged 50 and older. DESIGN: Randomized, blinded, placebo-controlled study. SETTING: Thirteen U.S. and seven European study sites. PARTICIPANTS: Three hundred eighty-two concomitantly, 380 sequentially vaccinated subjects. INTERVENTION: The concomitant vaccination group received influenza vaccine and ZOSTAVAX at separate injection sites on Day 1 and placebo at Week 4. The nonconcomitant vaccination group received influenza vaccine and placebo at separate injection sites on Day 1 and ZOSTAVAX at Week 4. MEASUREMENTS: Primary safety endpoints: vaccine-related serious adverse experiences (AEs) within 28 days postvaccination (PV); and diary card,prompted local and systemic AEs. Primary immunogenicity endpoints: geometric mean titer (GMT) and geometric mean fold rise (GMFR) from baseline of varicella-zoster virus (VZV) antibody (Ab) at 4 weeks PV according to glycoprotein enzyme-linked immunosorbent assay (gpELISA) and GMT of influenza Ab for the three vaccine strains (2005,2006 influenza season) at 4 weeks PV according to hemagglutination inhibition assay. Secondary immunogenicity endpoint: influenza seroconversion rates (SCRs). RESULTS: No serious AEs related to ZOSTAVAX were observed during the study. VZV Ab GMTs 4 weeks PV for the concomitant and sequential groups were 554 and 597 gpELISA U/mL, respectively. The estimated VZV Ab GMT ratio was 0.9 (95% confidence interval (CI)=0.8,1.0), indicating noninferior (P<.001 for the null hypothesis of GMT ratio <0.67) responses. Estimated VZV Ab GMFR from baseline in the concomitant group was 2.1 (95% CI=2.0,2.3), indicating acceptable fold rise. Estimated GMT ratios (concomitant/sequential) for influenza strains A(H1N1), A(H3N2), and B were 0.9 (95% CI=0.8,1.1), 1.1 (95% CI=0.9,1.3), and 0.9 (95% CI=0.8,1.1), respectively, and SCRs were comparable across both groups, with more than 85% achieving titers of 1:40 or greater, meeting regulatory criteria. CONCLUSION: ZOSTAVAX and influenza vaccine given concomitantly are generally well tolerated in adults aged 50 and older. Ab responses were similar whether ZOSTAVAX and influenza vaccine were given concomitantly or sequentially. [source] Safety and immunogenicity of live attenuated varicella vaccine in 9-month-old childrenPEDIATRICS INTERNATIONAL, Issue 6 2000Güler Kanra Background: The present study was conducted to evaluate the safety and immunogenicity of live attenuated varicella vaccine (Oka-strain) in 9-month-old infants. Methods: One hundred and fourteen infants were vaccinated once with live attenuated varicella vaccine (Valrix®; SmithKline Beecham Biologicals, Rixensart, Belgium) containing a mean virus titer of 104.0 plaque-forming units (p.f.u.) per dose. Signs and/or symptoms after vaccination were followed for 42 days. Home visits were made to detect solicited local reactions (0,3 days) and solicited general reactions (0,21 days), as well as unsolicited reactions. Specific varicella antibodies were determined by an indirect immunofluorescence method. The geometric mean titer and seroconversion rate were calculated. Results: Signs and/or symptoms were reported in 47.4% (54/114) of cases following vaccination. The only local symptom reported was pain on digital pressure at the injection site and this was reported in 28.1% (32/114) of infants. General symptoms were reported in 38.6% (44/114) of cases. The most frequently reported findings were fever (27.2%), which was mostly mild, restlessness (20.2%) and cough (11.4%). Only four unsolicited symptoms were reported and they were all unrelated to vaccination. No serious adverse event was reported. Of the 109 infants included in the immunogenicity analysis, 105 were seronegative and four were seropositive for antibodies against varicella before vaccination. The vaccine elicited seroconversion in 97.1% of initially seronegative cases. The post-vaccination geometric mean titer for these infants was 30.9 geometric mean titer (GMT). Conclusions: The vaccine was found to be safe and immunogenic when given to infants as young as 9 months of age. This may be of clinical significance during outbreaks of varicella and especially for developing countries. [source] Cellular and humoral immune responses to measles in immune adults re-immunized with measles vaccineJOURNAL OF MEDICAL VIROLOGY, Issue 2 2003Rosa Maria Wong-Chew Abstract The objective of this study was to characterize the kinetics of the cellular and humoral immune responses elicited by measles vaccine given to previously immune adults. The cellular and humoral immune responses to measles were measured in seven healthy adults, before vaccination and at 1, 2, 3, and 4 weeks and 3 months after vaccination, using measles-specific T-cell proliferation and plaque reduction neutralization assays. All study subjects had detectable measles antibodies, but only six (85%) showed protective titers, defined as >1:120, before immunization. However measles-specific T-cell proliferation was not detectable before vaccination in any of the subjects. The six subjects with protective titers showed a positive stimulation index (SI) of >3.0 within the first 4 weeks after vaccination, an SI of 5 at the 4th week, and an SI of 3 at 3 months after vaccination. The subject with a low antibody titer (1:99) before vaccination developed a high SI at 3 months after vaccination. This subject was the only participant whose neutralizing antibody titers increased more than 4-fold by 3 months after vaccination. No significant increases in geometric mean titers were detected in the other six subjects during the follow-up period. These data suggest that high measles antibody titers interfere with the humoral response in subjects who receive a booster immunization, whereas the cellular response is boosted at least transiently, after revaccination. J. Med. Virol. 70: 276,280, 2003. © 2003 Wiley-Liss, Inc. [source] Immunogenicity of Pneumococcal Vaccine in Renal Transplant Recipients,Three Year Follow-up of a Randomized TrialAMERICAN JOURNAL OF TRANSPLANTATION, Issue 3 2007D. Kumar Routine pneumococcal vaccination is recommended at regular intervals posttransplant. However, there is limited data on durability of vaccine response and the impact of vaccine type on antibody persistence. We determined the durability of response for patients enrolled in a randomized trial of conjugate (PCV7) versus polysaccharide (PPV23) pneumococcal vaccination. Response was defined as a twofold increase from baseline and a titer ,0.35 ,g/mL using a pneumococcal ELISA for seven serotypes (measured at 8 weeks and 3 years). Forty-seven patients were evaluated and had received either PPV23 (n = 24) or PCV7 (n = 23). Response rates and geometric mean titers varied by serotype but declined significantly at 3-years for 6 of 7 serotypes (p < 0.001). No significant difference in durability was found in patients that had received PPV23 versus PCV7. Compared to the 8-week response, 20.6% fewer patients had a response to at least one serotype by 3 years. The largest relative declines were seen for serotype 4 (response dropped from 40.4% at 8 weeks to 17.0% at 3 years) and serotype 9V (44.7% dropping to 21.3%). The only factor predictive of response durability was a strong multiserotype initial response (p < 0.001). In conclusion, vaccine responses decline significantly by 3 years and conjugate vaccine does not improve the durability of response. [source] Humoral responses after influenza vaccination are severely reduced in patients with rheumatoid arthritis treated with rituximab,ARTHRITIS & RHEUMATISM, Issue 1 2010Sander van Assen Objective For patients with rheumatoid arthritis (RA), yearly influenza vaccination is recommended. However, its efficacy in patients treated with rituximab is unknown. The objectives of this study were to investigate the efficacy of influenza vaccination in RA patients treated with rituximab and to investigate the duration of the possible suppression of the humoral immune response following rituximab treatment. We also undertook to assess the safety of influenza vaccination and the effects of previous influenza vaccination. Methods Trivalent influenza subunit vaccine was administered to 23 RA patients who had received rituximab (4,8 weeks after rituximab for 11 patients [the early rituximab subgroup] and 6,10 months after rituximab for 12 patients [the late rituximab subgroup]), 20 RA patients receiving methotrexate (MTX), and 29 healthy controls. Levels of antibodies against the 3 vaccine strains were measured before and 28 days after vaccination using hemagglutination inhibition assay. The Disease Activity Score in 28 joints (DAS28) was used to assess RA activity. Results Following vaccination, geometric mean titers (GMTs) of antiinfluenza antibodies significantly increased for all influenza strains in the MTX-treated group and in healthy controls, but for no strains in the rituximab-treated group. However, in the late rituximab subgroup, a rise in GMT for the A/H3N2 and A/H1N1 strains was demonstrated, in the absence of a repopulation of CD19+ cells at the time of vaccination. Seroconversion and seroprotection occurred less often in the rituximab-treated group than in the MTX-treated group for the A/H3N2 and A/H1N1 strains, while seroprotection occurred less often in the rituximab-treated group than in the healthy controls for the A/H1N1 strain. Compared with unvaccinated patients in the rituximab-treated group, previously vaccinated patients in the rituximab-treated group had higher pre- and postvaccination GMTs for the A/H1N1 strain. The DAS28 did not change after vaccination. Conclusion Rituximab reduces humoral responses following influenza vaccination in RA patients, with a modestly restored response 6,10 months after rituximab administration. Previous influenza vaccination in rituximab-treated patients increases pre- and postvaccination titers. RA activity was not influenced. [source] | ||||||||||