The vaccine will comprise antigen of the recently isolated Pandemic (H1N1) 2009 influenza strain and also contain GSK's proprietary adjuvant system AS03. In clinical studies using the bird flu influenza strain (H5N1), the adjuvanted formulation has been shown to stimulate a higher immune response while using a smaller amount of antigen as compared to a formulation without adjuvant. The vaccine containing the adjuvant system therefore helps to substantially increase the number of vaccine doses that can be provided for mass vaccination.(1) In addition, in clinical studies with the bird flu programme, the adjuvanted vaccine demonstrated the potential to provide protection even if the influenza strain drifts (changes slightly).(2,3) Both the antigen sparing approach as well as the potential for additional protection against drifting strains are features for an impactful vaccine for use in a pandemic setting. GSK has received regulatory approvals in the European Union and some Asian countries for its pre-pandemic and pandemic H5N1 vaccines, both of which contain the AS03 adjuvant. Currently, clinical trials in over 39,000 people have demonstrated that the AS03 adjuvant system used with an influenza vaccine has an acceptable safety and reactogenicity profile. About the clinical trials
The first clinical trial, being conducted in Germany, has started this week and enrolment has been completed. The trial will assess the use of the vaccine given as 2 doses, 21 days apart in 128 healthy adults, aged between 18 and 60. Initial data is expected to be available for submission to regulatory authorities in September. Additional trials planned in the clinical development programme are expected to commence shortly and include 8 trials in healthy adults, 5 trials in children (including infants) and 2 trials in the elderly. Details of the clinical development programme will be posted to www.clinicaltrials.gov. GlaxoSmithKline - one of the world's leading research-based pharmaceutical and healthcare companies - is committed to improving the quality of human life by enabling people to do more, feel better and live longer. For further information please visit www.gsk.com. 1. Leroux-Roels et al. Antigen sparing and cross-reactive immunity with an adjuvanted rH5N1 prototype pandemic influenza vaccine: a randomised controlled trial. Lancet 2007; 370 (9587): 580–89.
2. Leroux-Roels I et al, Broad Clade 2 Cross-Reactive Immunity Induced by an Adjuvant systemed Clade 1 rH5N1 Pandemic Influenza Vaccine PLoS ONE 3(2): e 1665. doi:10.1371/jounal.pone.0001665
3. Baras et al. Cross-protection against lethal H5N1 challenge in ferrets with an adjuvanted pandemic influenza vaccine. PLoS ONE 2008; 3 (1): e1401.