Contract Awarded to Develop Vaccine Against H9N2 Avian Influenza

The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), has awarded a contract to Chiron Corporation of Emeryville, Calif., for the production of an investigational vaccine based on an H9N2 strain of avian influenza virus that has infected humans and has the potential to trigger a modern-day pandemic.

This project, which is part of the NIAID Pandemic Influenza Preparedness Program, is the second recently announced by NIAID that supports the development and production of a candidate vaccine against a pandemic strain of avian influenza. The other NIAID project targets the H5N1 strain that has resurfaced in Asia after an outbreak earlier this year. In 2004, H5N1 has caused 27 deaths.

In 1999 and 2003, an H9N2 influenza strain caused illness in three people in Hong Kong. Scientists are concerned about H9N2 and other emerging types of avian influenza viruses because as they spread -- most commonly through poultry -- they continually mutate, increasing chances that they may infect humans, evade the bodys immune response and become more lethal. Of greatest concern is that these ever-changing avian viruses could develop the ability to spread from person to person, resulting in a fast-moving, global pandemic.

Given the poor condition of public health systems in many developing regions and the ubiquity of modern air travel, the consequences of a widespread outbreak of avian influenza in humans could be severe, says Anthony S. Fauci, MD, director of NIAID. Information generated under this contract will be important for preparing our nation and the world against new influenza viruses with pandemic potential.

Chiron Corporation will produce the H9N2 vaccine at its manufacturing facility in Siena, Italy. The company will prepare different dosages of the vaccine, which is based on an inactivated strain of the H9N2 virus developed by the Centers for Disease Control and Prevention (CDC). Some dosages will contain Chirons MF59 adjuvant -- a substance designed to boost the vaccines protective effect.

The company will produce up to 40,000 doses of vaccine with and without the MF59 adjuvant for clinical trials that will be conducted by NIAID. These trials are currently slated for early next year.

Because avian influenza viruses like H9N2 have not previously circulated widely among humans, we are likely to have limited, if any, immunity against them. Understanding through clinical trials the safety of the vaccine and the dosage level that will generate a protective immune response is critical, says Linda Lambert, PhD, who oversees the clinical influenza research program funded by the division of microbiology and infectious diseases at NIAID. By comparing the vaccines with and without the MF59 adjuvant, we can determine if the adjuvant significantly augments the protective effects of the vaccine, enabling us to use lower doses and thereby extend the vaccine supply.

Lambert says that this contract follows one of the key tenets of the NIAID Pandemic Influenza Preparedness Program that supports working with both U.S. and international companies to develop and evaluate the safety and effectiveness of vaccines against influenza viruses with pandemic potential. Results from this project will not only provide important public health information, but may also help make new types of influenza vaccines available to the public.

A major component of our strategy is to partner with private-sector companies around the world to develop and clinically test promising new vaccine technologies, she says. The more studies we can also do with novel types of avian influenza strains such as H9N2 and H5N1, the more likely it is that we may begin to identify patterns that allow us to counteract all of them.

Source: National Institutes of Health