February 19, 2007

The U.N. World Health Organization (WHO) held a meeting late last week at its headquarters in Geneva to discuss progress in pandemic influenza vaccine development.

Sixteen manufacturers are developing prototype pandemic influenza vaccines against the H5N1 avian influenza virus, according to WHO. Five of them are also involved in the development of vaccines against other avian viruses, including H9N2, H5N2 and H5N3.

At present, more then 40 clinical trials have been completed or are ongoing, WHO reports. Most of them have focused on healthy adults, but some companies have conducted trials in children and the elderly. All vaccines were safe and well tolerated in all age groups tested.

Data presented at the meeting have convincingly demonstrated that vaccination with newly developed avian influenza vaccines can bring about a potentially protective immune response against strains of the H5N1 virus. Some of the vaccines work with low doses of antigen, which means that significantly more vaccine doses can be available in case of a pandemic.

Despite this encouraging progress, WHO stresses that the world still lacks the manufacturing capacity to meet potential global pandemic influenza vaccine demand. Current capacity is estimated at less than 400 million doses per year of trivalent seasonal influenza vaccine.

Agency officials also met with the Indonesia's minister of health, Siti Fadillah Supari, to discuss the sharing of influenza virus samples with WHO and with vaccine production companies.