A set of activities identified in the World Health Organization's (WHO's) new Global pandemic influenza action plan to increase vaccine supply requires immediate and sustained action and funding, if the world is to be prepared for an influenza pandemic to which there would be almost universal susceptibility.
"We are presently several billion doses short of the amount of pandemic influenza vaccine we would need to protect the global population. This situation could lead to a public health crisis," said Dr Marie-Paule Kieny, Director, WHO Initiative for Vaccine Research. "The Global Action Plan sets the course for what needs to be done, starting now, to increase vaccine production capacity and close the gap. In just three to five years we could begin to see results that could save many lives in case of a pandemic."
The Global Action Plan is the product of the advice of more than 120 scientific experts from national immunization programmes, national regulatory authorities, scientists and vaccine manufacturers in both industrialized and developing countries.
It identifies and prioritizes practical solutions for reducing the potential pandemic influenza vaccine supply gap; these are contained in eight strategies with activities for the short (tangible results in less than five years), medium (five to ten years) and long (more than ten years) terms. Activities need to be undertaken simultaneously.
"Immunization is a critical control strategy for limiting the impact of an influenza pandemic. Immediate, collaborative action to increase vaccine supply could have a massive payoff," said Dr David L. Heymann, acting Assistant Director-General, Communicable Diseases, WHO. "In addition, continued participation of countries in the timely sharing of their influenza viruses and sequence data is vital to support global vaccination efforts," he added.
The three main approaches to closing the vaccine supply gap are identified in the Global Action Plan as:
- an increase in seasonal influenza vaccine use to provide protection against seasonal influenza and at the same time use the increased demand to stimulate industry to produce more;
- an increase in production capacity through measures such as improving vaccine production yields and building new plants; and
- further research and development to:
- design more potent and effective vaccines that would induce protection after one dose and/or broad spectrum and long-lasting immunity, and
- produce vaccines more efficiently and quickly.
Relying on market-driven forces alone, it is estimated that by 2008-2009 the production of pandemic influenza vaccine will not exceed 2.34 billion doses per year. At present, the production capacity for seasonal influenza vaccine stands at 350 million doses. Such quantities fall far short of the expected demand for vaccine during an influenza pandemic when there will likely be calls to vaccinate the entire 6.7 billion world population. The anticipated shortage is, in particular, due to the expectation that a two-dose course of vaccine will be needed to protect each person.
New technologies will play an important role in developing the best possible pandemic influenza vaccine. The ideal vaccine would be safe and highly protective in all target groups (including infants, the elderly, etc.) for at least one year with only a single dose. It would require just a small amount of virus antigen and could be stored without refrigeration. Finally, the vaccine would be easily and inexpensively produced on a large scale.