Acellular pertussis vaccines: the rationale for an efficacy trial in Germany

Recommendations and evidence for reporting items in pediatric clinical trial protocols and reports: two systematic reviews

BACKGROUND

Complete and transparent reporting of clinical trial protocols and reports ensures that these documents are useful to all stakeholders, that bias is minimized, and that the research is not wasted. However, current studies repeatedly conclude that pediatric trial protocols and reports are not appropriately reported. Guidelines like SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) and CONSORT (Consolidated Standards of Reporting Trials) may improve reporting, but do not offer guidance on issues unique to pediatric trials. This paper reports two systematic reviews conducted to build the evidence base for the development of pediatric reporting guideline extensions: 1) SPIRIT-Children (SPIRIT-C) for pediatric trial protocols, and 2) CONSORT-Children (CONSORT-C) for pediatric trial reports.

METHOD

MEDLINE, the Cochrane Methodology Register, and reference lists of included studies were searched. Publications of any type were eligible if they included explicit recommendations or empirical evidence for the reporting of potential items in a pediatric protocol (SPIRIT-C systematic review) or trial report (CONSORT-C systematic review). Study characteristics, recommendations and evidence for pediatric extension items were extracted. Recurrent themes in the recommendations and evidence were identified and synthesized. All steps were conducted by two reviewers.

RESULTS

For the SPIRIT-C and CONSORT-C systematic reviews 366 and 429 publications were included, respectively. Recommendations were identified for 48 of 50 original reporting items and sub-items from SPIRIT, 15 of 20 potential SPIRIT-C reporting items, all 37 original CONSORT items and sub-items, and 16 of 22 potential CONSORT-C reporting items. The following overarching themes of evidence to support or refute the utility of reporting items were identified: transparency; reproducibility; interpretability; usefulness; internal validity; external validity; reporting bias; publication bias; accountability; scientific soundness; and research ethics.

CONCLUSION

These systematic reviews are the first to systematically gather evidence and recommendations for the reporting of specific items in pediatric protocols and trials. They provide useful and translatable evidence on which to build pediatric extensions to the SPIRIT and CONSORT reporting guidelines. The resulting SPIRIT-C and CONSORT-C will provide guidance to the authors of pediatric protocols and reports, respectively, helping to alleviate concerns of inappropriate and inconsistent reporting, and reduce research waste.

WITHDRAWN: Acellular vaccines for preventing whooping cough in children

BACKGROUND

Routine use of whole cell pertussis vaccines was suspended in some countries in the late 1970s and early 1980s, leading to a resurgence of whooping cough. Acellular pertussis vaccines containing purified or recombinant Bordetella pertussis antigens were developed in the hope that they would be as effective but less toxic than the whole cell vaccines.

OBJECTIVES

The objective of this review was to assess the effects of acellular pertussis vaccines in children.

SEARCH STRATEGY

The Cochrane Controlled Trials Register and Medline were searched up to January 1998.

SELECTION CRITERIA

Double-blind randomised efficacy and safety trials of acellular pertussis vaccines in children, with active follow-up of participants and laboratory verification of pertussis cases.

DATA COLLECTION AND ANALYSIS

One reviewer assessed trial quality and extracted data.

MAIN RESULTS

Six efficacy trials and 45 safety trials were included. Acellular pertussis vaccines with three or more pertussis vaccines were more effective than those with one or two antigens. They were also more effective than one type of whole cell pertussis vaccine, but less effective than two other types of whole cell vaccines. Differences in trial design precluded pooling of the efficacy data and results should be interpreted with caution. Most systemic and local adverse events were significantly less common with acellular than with whole cell pertussis vaccines.

AUTHORS' CONCLUSIONS

Multi-component acellular pertussis vaccines are effective, and show less adverse effects than whole cell pertussis vaccines. However in areas where whooping cough is more likely to be fatal, the higher toxicity of some whole cell vaccines may be offset by their increased effectiveness.

Comparison of five commercial enzyme-linked immunosorbent assays for detection of antibodies to Bordetella pertussis

Measuring antibodies to Bordetella pertussis antigens is mostly done by enzyme-linked immunosorbent assays (ELISAs). We compared the performance of five commercially available ELISA kits with the help of 65 serum specimens which were repetitively tested for evaluation of the kits. The specimens contained 20 paired serum samples from patients with clinical pertussis, 15 samples were from children vaccinated with a diphtheria-tetanus-acellular pertussis vaccine, seven specimens were taken from an interlaboratory comparison of ELISAs, and there were three reference preparations from the Food and Drug Administration's (FDA's) Laboratory of Pertussis and from our laboratory. Reference values were obtained from the FDA or from results obtained with an in-house ELISA. Commercial ELISAs were compared with respect to their reproducibility and variability, their ability to detect significant titer rises in paired serum samples, their ability to detect an immune response after vaccination, and the comparability of semiquantitative and quantitative results. Reproducibility was generally good (>89%), intra-assay variation ranged from 2.4 to 28.7%, and indeterminate results were recorded in up to 18.5% of all specimens. Most kits correctly identified the antibody response to an acellular pertussis vaccine. None of the commercial kits identified all cases of pertussis correctly, and the sensitivity ranged between 60 and 95%. All five commercial ELISAs showed great discrepancies when comparing semiquantitative results and contained obviously different antigen preparations. Our data suggest that the five commercial ELISAs tested here need further improvement and standardization.