GlaxoSmithKline (GSK) started an international clinical trial programme to test two pandemic vaccines against the H5N1 strain of the avian influenza virus in humans.
A clinical trial just initiated in 400 healthy adult volunteers in Germany is testing a pandemic flu vaccine using a classic alum adjuvant to improve individual's immune response and possibly allow a lower amount of antigen to be used per dose. This trial supports a dossier GSK submitted to European regulators in December 2005. Should a pandemic flu strain be identified by the World Health Organization, a variation to the dossier would allow rapid European registration and production of a pandemic vaccine, according to a company release.
In parallel, a clinical trial conducted in Belgium in 400 healthy adults is testing a candidate pandemic flu vaccine that contains a novel adjuvant system. GSK is hopeful that a vaccine formulated with this novel adjuvant will further enable individual's immune system to respond to different H5N1 virus strains, offering a broader protection against the threat of a pandemic. GSK's novel adjuvant technology is also expected to further reduce the amount of antigen needed per dose, increasing the number of doses the company could make available worldwide. Such a vaccine would offer governments additional options of stockpiling and vaccinating ahead of a pandemic outbreak.
Both trials are testing the vaccine's safety and ability to boost individuals' immune response against H5N1. Tested vaccines are made from inactivated (killed) H5N1 virus. Different dose levels are being studied. Volunteers are to receive two vaccinations approximately three weeks apart. The studies will allow GSK to select an optimal dose and formulation for subsequent safety trials in groups at high risk of complications following influenza infection, such as children and the elderly.
Preliminary results from the clinical trials are expected in the third quarter of 2006. GSK plans to have a pandemic flu vaccine in production before the end of the year, added the release.
Jean Stéphenne, President of GSK Biologicals, the vaccine division of GSK said: "We are moving forward with clinical trials of vaccines which could prove a vital part of the world's response to a flu pandemic. 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."