Brussels, 31 Mar 2006
Pharmaceuticals giant GlaxoSmithKline (GSK) has begun clinical trials in Germany and Belgium of two 'pandemic vaccines' against the H5N1 strain of avian influenza in humans, saying that mass production of a pandemic flu vaccine could begin within the year.
The company is testing two different types of vaccine to assess their safety and ability to boost individuals' immune response against H5N1. The first, being tested on 400 healthy adult volunteers in Germany, is based on a classic alum adjuvant, or additive, while the second vaccine, being tested on an identical number of volunteers in Belgium, is based on a novel adjuvant system which could protect against multiple strains of the H5N1 virus.
According to Jean Stéphenne, President of GSK Biologicals: 'While the first vaccine candidate aims at mounting a strong defence against a pandemic outbreak, the second vaccine may offer governments a preferred option to proactively stockpile and begin vaccination before the onset of a pandemic, significantly increasing the speed of a public health response in the event of an outbreak.'
The first trial in Germany supports a 'mock-up' dossier submitted to the European Medicines Evaluation Agency (EMEA) in December 2005, which provides for an accelerated review status for the vaccine. GSK is the first pharmaceutical manufacturer to do so under new EU rules designed to fast-track approvals.
The second trial is based on a novel approach to vaccine production, which GSK says will allow the company to further reduce the amount of antigen needed per dose, thus increasing the overall number of doses that the company can make available worldwide. In both trials, different dose levels are being studied in order to allow selection of optimal doses for further trials and production.
Results of the first human trials of an H5N1 vaccine, which took place in the United States, found that two doses of 90 micrograms of antigen were required to trigger a protective immune response in just over half of the volunteers. While GSK acknowledges that its vaccines are being tested at lower dosages than the US trial, the company remains confident that one of the two antigens will produce a superior immune response.
Many experts warn that there is no guarantee that vaccines developed now will prove effective in the case of a pandemic, as no-one can be sure exactly what type of strain might emerge. However, many also acknowledge that such vaccines could prime the human immune system for an attack.
GSK's head of flu operations worldwide, Emmanuel Hanon, concludes: 'We believe that vaccinating populations with the appropriate H5N1 vaccine will help educate the body's immune system and reduce expected morbidity and mortality associated with a pandemic.'
Elsewhere, on 30 March the European Commission published a final evaluation report of a two-day simulation exercise designed to test how well national preparedness plans would work together in the event of a flu pandemic. The report concluded that the exercise was a 'successful event', showing considerable improvements from earlier exercises, but identified a number of issues for further improvement.
The Commission's early warning and response system (EWRS) proved a robust tool and was used extensively. However, it became overloaded as it was used as a crisis management tool when it had only been developed for notification and coordination purposes. Back-up communication facilities should be considered, and the coordination of media communications should be improved by establishing a network of media contacts in national ministries across the EU.
The simulation exercise took place on 23 and 24 November, and involved hundreds of participants from the Commission, EU agencies, Member States, third countries and the pharmaceutical industry.