摘要:

Background.Antibody persistence was studied in 5.5-year-old Swedish children who in infancy completed a vaccine trial of a combined diphtheria toxoid, tetanus toxoid, acellular pertussis, inactivated polio andHaemophilus influenzaetype b conjugate vaccine. Three priming doses at ages 2-4-6 months induced higher geometric mean concentrations of antibodies for all antigens than did two doses at 3-5 months, but there were no differences in proportions with protective antibody concentrations. After the booster dose administered at 13 or 12 months of age, respectively, there were no differences in concentrations or proportions between the groups.Methods.In the present follow-up serum samples from 180 of the 228 vaccinees, 88 from the 4-dose and 92 from the 3-dose group, were 4.5 years later again tested for antibodies.Results.The two groups did not differ significantly in antibody concentrations or proportions with antibodies above protective or other defined levels, with the exception of poliovirus type 3 (P≤ 0.01). In all 89% had ≥0.01 IU/ml antibodies against diphtheria by enzyme-linked immunosorbent assay and 76% by the Vero cell neutralization test, 93% had ≥0.01 IU/ml antibodies against tetanus, 96 to 99% had detectable antibodies against the polioviruses and 97% had ≥0.15 &mgr;g/mlH. influenzaetype b antibodies. As for pertussis only 44% had detectable antibodies against pertussis toxoid by enzyme-linked immunosorbent assay but 99% by Chinese hamster ovary cell neutralization test, and 94% had detectable antibodies against filamentous hemagglutinin.Conclusion.We found the persistence of antibodies satisfactory, with no clinically relevant differences in antibody concentrations demonstrated between children vaccinated according to a three dose or a four dose schedule in infancy.

ISSN:0891-3668    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Background.After licensing of a varicella vaccine in Canada in 1998, Health Canada commissioned a study to evaluate options for a vaccination program. The evaluation of a program of vaccination of 12-month-old children, with and without a catch-up program for susceptible 12-year-olds, is presented here.Methods.An economic model was developed simulating the expected experience, with and without vaccination, of cohorts of children susceptible to varicella. The cohorts were simulated for 70 years, and infection and complication rates were calculated along with the attendant costs, with an assumed vaccine cost of $60.Results.With an 85% coverage rate vaccination is expected to reduce the number of chickenpox cases by approximately two-thirds and varicella-related complications by up to 75%. The overall costs of varicella are expected to drop by >$4 million (1998 Canadian dollars) per 100 000 eligible vaccinees, but costs to the health care system are expected to increase by >$2 million. From the health care system perspective, vaccination would cost ∼$42 per discounted case avoided.Interpretation.Routine varicella vaccination would likely substantially reduce the overall costs of managing chickenpox but would result in an increase in health care expenditures. These findings are consistent with evaluations in other countries.

ISSN:0891-3668    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Background.Development of protein-conjugated pneumococcal vaccines for infants has led to formulations that are immunogenic in the age group at highest risk for pneumococcal diseases. This study focuses on the search for an optimal formulation.Methods.In a randomized trial Icelandic infants (n= 160) were immunized at age 3, 4 and 6 months with one of two octavalent pneumococcal conjugate vaccines (serotypes 3, 4, 6B, 9V, 14, 18C, 19F and 23F conjugated to diphtheria toxoid (PncD) or tetanus protein (PncT) followed with a booster of either the same conjugate or 23-valent polysaccharide vaccine at 13 months. Safety data were collected after each vaccination, and IgG responses (enzyme-linked immunosorbent assay) were measured at 3, 4, 6, 7, 13 and 14 months.Results.Both conjugates were safe and caused fewer local reactions than the routine vaccines (P< 0.0001). At 7 months both groups had significant IgG response to all serotypes. The geometric mean concentration range was 0.35 to 4.09 and 0.65 to 3.38 &mgr;g/ml for PncD and PncT, respectively, with 88.2 to 100% and 92.4 to 100% of subjects reaching ≥0.15 &mgr;g/ml. The PncD gave better primary responses to serotypes 3, 9V and 18C, whereas PncT gave better response to serotype 4. Similar responses were induced to the other serotypes. Good booster IgG responses were obtained in all vaccine groups; 97.5 to 100% of subjects reached ≥1 &mgr;g/ml.Conclusions.Both octavalent pneumococcal conjugates were safe and immunogenic in infants. Based on the results from this and similar trials, a mixed diphtheria and tetanus pneumococcal conjugate vaccine was designed to provide the optimal immune response to each serotype.

ISSN:0891-3668    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Background.Administration of M-M-R II (Measles, Mumps and Rubella Virus Vaccine, Live) and VARIVAX [Varicella Virus Vaccine Live (Oka/Merck)] given concomitantly at separate injection sites during the same office visit could increase vaccine compliance by reducing the number of health care visits for immunizations. We compared the safety and immunogenicity of M-M-R II and VARIVAX given concomitantly at separate sites (Group A) with administration of the two vaccines 6 weeks apart (Group B) as well as the persistence of varicella antibody and the duration of protection afforded by varicella vaccine.Methods.A total of 603 healthy children, ages 12 months to 6 years, with no history of measles, mumps, rubella, varicella and zoster or vaccination against these diseases, were randomized to either Group A or B and were followed for clinical reactions and serologic responses to all four viral components. Children were enrolled from August through December, 1993. Subjects were followed for 5 years to evaluate persistence of varicella antibody and breakthrough varicella rates. We compared breakthrough rates to expected attack rates in unvaccinated children to produce estimates of vaccine efficacy.Results.Both vaccine regimens were generally well-tolerated. There were no significant differences between the groups in the rates of fever, injection site reactions or rashes after vaccination. Seroconversion rates and geometric mean titers for measles, mumps and rubella were not significantly different between groups. The varicella seroconversion rate and percentage with glycoprotein-based ELISA titers ≥5.0 units were similar between the two groups (99.5 and 92.5%vs.100 and 94.8% for Groups A and B, respectively), but the geometric mean titers were statistically significantly different (13.2 for Group A and 17.9 for Group B). Varicella antibody persistence rates were >98 to 100% during 6 years of follow-up in both groups. Compared with historical rates, varicella vaccine efficacy during 5 years was estimated to be 90.5% (95% confidence interval, 86.2%, 95.0%) and 88.9% (95% confidence interval, 83.7%, 93.7%) in Groups A and B, respectively.Conclusions.Administration of M-M-R II and VARIVAX concomitantly at separate injection sites or 6 weeks apart was generally well-tolerated and immunogenic in healthy children 12 months to 6 years of age. VARIVAX administered with M-M-R II induced persistent immunity and long-term protection against breakthrough varicella infection.

ISSN:0891-3668    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0891-3668    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0891-3668    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0891-3668    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0891-3668    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0891-3668    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0891-3668    

出版商:OVID    

年代:2002

数据来源: OVID