European Vaccine Initiative: lessons from developing malaria vaccines.

For over 10 years, the European Vaccine Initiative (EVI; European Malaria Vaccine Initiative until 2009) has contributed to the development of 24 malaria candidate vaccine antigens with 13 vaccine candidates being advanced into Phase I clinical trials, two of which have been transitioned for further clinical development in sub-Saharan Africa. Since its inception the EVI organization has operated as a funding agency, but with a clear service-oriented strategy. The scientific successes and difficulties encountered during these years and how these efforts have led to standardization and harmonization in vaccine development through large-scale European consortia are discussed. In the future, the EVI will remain instrumental in the pharmaceutical and clinical development of vaccines against 'diseases of poverty' with a continued focus on malaria. EVI will continue to focus on funding and managing preclinical evaluation up to Phase I/II clinical trials and strengthening the vaccine-development infrastructure in Europe, albeit with a global orientation.

WHO Working Group on revision of the Manual of Laboratory Methods for Testing DTP Vaccines-Report of two meetings held on 20-21 July 2006 and 28-30 March 2007, Geneva, Switzerland.

This report reflects the discussion and conclusions of a WHO group of experts from National Regulatory Authorities (NRAs), National Control Laboratories (NCLs), vaccine industries and other relevant institutions involved in standardization and control of diphtheria, tetanus and pertussis vaccines (DTP), held on 20-21 July 2006 and 28-30 March 2007, in Geneva Switzerland for the revision of WHO Manual for quality control of DTP vaccines. Taking into account recent developments and standardization in quality control methods and the revision of WHO recommendations for D, T, P vaccines, and a need for updating the manual has been recognized. In these two meetings the current situation of quality control methods in terms of potency, safety and identity tests for DTP vaccines and statistical analysis of data were reviewed. Based on the WHO recommendations and recent validation of testing methods, the content of current manual were reviewed and discussed. The group agreed that the principles to be observed in selecting methods included identifying those critical for assuring safety, efficacy and quality and which were consistent with WHO recommendations/requirements. Methods that were well recognized but not yet included in current Recommendations should be taken into account. These would include in vivo and/or in vitro methods for determining potency, safety testing and identity. The statistical analysis of the data should be revised and updated. It was noted that the mouse based assays for toxoid potency were still quite widely used and it was desirable to establish appropriate standards for these to enable the results to be related to the standard guinea pig assays. The working group was met again to review the first drafts and to input further suggestions or amendments to the contributions of the drafting groups. The revised manual was to be finalized and published by WHO.

New live mycobacterial vaccines: the Geneva consensus on essential steps towards clinical development.

As the disease caused by Mycobacterium tuberculosis continues to be a burden, which the world continues to suffer, there is a concerted effort to find new vaccines to combat this problem. Of the various vaccines strategies, one viable option is the development of live mycobacterial vaccines. A meeting with researchers, regulatory bodies, vaccines developers and manufactures was held to consider the challenges and progress, which has been achieved with live mycobacterial vaccines (either modified BCG or attenuated M. tuberculosis). Discussion led to the production of a consensus document of the proposed entry criteria for Phase I clinical trials of candidate live mycobacterial vaccines. The vaccine must be characterised thoroughly to prove identity and consistency, as clinical trial lots are prepared. In pre-clinical studies, greater protective efficacy as well as improved safety potential relative to BCG should be considered when assessing potential vaccine candidates. A standard way to measure the protective efficacy to facilitate comparison between vaccine candidates was suggested. Additional safety criteria and verification of attenuation must be considered for attenuated M. tuberculosis. Two non-reverting independent mutations are recommended for such vaccines. When entering Phase I trials, enrollment should be based upon an acceptable characterisation of the study population regarding mycobacterium status and exclude HIV(+) individuals. BCG could be used as a comparator for blinding during the trials and to properly assess vaccine-specific adverse reactions, while assays are being developed to assess immunogenicity of vaccines. The proposed criteria suggested in this consensus document may facilitate the movement of the most promising vaccine candidates to the clinic and towards control of tuberculosis.

European union regulatory developments for new vaccine adjuvants and delivery systems.

Interest in vaccine adjuvants and new delivery systems has grown rapidly over the past few years. New vaccine candidates have emerged, which, because of their poor immunogenicity, rely on adjuvants to improve their presentation and targeting and to potentiate their protective immune response. Better understandings of the mechanisms of action, together with logistic and economical considerations have resulted in an explosion of technologies. However, there have been few new registered products for human use, and antigens incorporated into immunostimulating reconstituted influenza virosomes have only relatively recently been licensed in European Union (EU) countries. Influenza vaccine, adjuvanted with water in oil emulsion containing squalene (adjuvant MF59C1) is now also approved. Although current EU regulations focus on traditional adjuvants, notably aluminium and calcium salts, advances have been made in regulatory considerations. The European agency for the evaluation of medicinal products, through its working parties, is actively drafting guidance on requirements for the evaluation of new adjuvants in vaccines. This paper summarises the new developments in EU regulatory aspects relevant to adjuvant quality at development stages, during the manufacturing process, and at the final bulk stage of adjuvant with antigen, and also summarises regulatory expectation regarding safety at pre-clinical and clinical stages. The paper highlights the regulatory concerns and existing bottlenecks that have led to slow approval of new technologies.

Collaborative study for the establishment of a European Phamacopoeia Biological reference preparation for Bordetella pertussis mouse antiserum for serological potency testing of acellular pertussis vaccines.

A collaborative study was organised by the European Directorate For the Quality of Medicines (EDQM) to assess the suitability of a candidate mouse antiserum as a European Pharmacopoeia Biological reference preparation (BRP) for acellular pertussis vaccine potency testing. The candidate antiserum was obtained by immunising mice with a five-component acellular pertussis vaccine: pertussis toxin (PT), filamentous haemagglutinin (FHA), pertactin (PRN) and Fimbrial 2/Fimbrial 3 (Fim 2&3). The study has been divided into two separate phases. Phase I was a pre-qualification study including three laboratories. This phase was aimed at pre-qualifying the candidate BRP (cBRP) and at documenting the impact of differences in the antibody detection methodology enzyme linked immunosorbent assay (ELISA) procedures on results of pertussis antisera calibration versus the currently used standard US standard pertussis antiserum (mouse) Lot 1 (SPAM-1) (United States Food and Drug Administration (USFDA) reference serum) and the cBRP. As no significant difference between the antibody titres determined by using the different ELISA methodologies was found, a large-scale study enrolling 13 laboratories (Phase II) was carried out, each participant performing its in-house methodology. Its aim was to calibrate the cBRP (in terms of the SPAM-1 reference) and to demonstrate its equivalence or superiority to internal references. The study showed that there was no difference in positive sera titres expressed relative to their corresponding internal reference (homologous situation) or the proposed standard (heterologous situation) reference. The cBRP can, therefore, reliably act as replacement for the in-house reference preparations. Further analysis of the outcome of this study enabled to assign to the cBRP a potency of 39, 138, 34 and 56 ELISA unit per millilitre, respectively, to its anti-PT, anti-FHA, anti-PRN and anti-Fim 2&3 antibody contents. The cBRP has been adopted by the European Pharmacopoeia Commission at its June 2000 session as Bordetella pertussis mouse anti-serum Ph Eur. BRP batch 1.