WHO reports promising H5N1 vaccine results but says production capacity too low

Experts meeting in Switzerland over the past two days at the World Health Organization (WHO) on advances in pandemic influenza vaccine development reported encouraging progress.

It said 16 manufacturers from 10 countries are developing prototype pandemic influenza vaccines against H5N1 avian influenza virus. Five of them are also involved in the development of vaccines against other avian viruses (H9N2, H5N2, and H5N3).

At present, more then 40 clinical trials have been completed or are ongoing. Most of them have focused on healthy adults. Some companies, after completing safety analyses in adults, have initiated clinical trials in the elderly and in children. All vaccines were safe and well tolerated in all age groups tested.

These developments were discussed at the WHO meeting on the evaluation of pandemic influenza prototype vaccines in clinical trials that took place in Geneva, Switzerland, on 15-16 February 2007.

In spite of the encouraging progress noted at the WHO meeting, WHO stresses that the world still lacks the manufacturing capacity to meet potential global pandemic influenza vaccine demand as current capacity is estimated at less than 400 million doses per year of trivalent seasonal influenza vaccine.