The quest for a fully immunogenic vaccine against influenza H5N1 viruses has gone on for more than 10 years, since this family of potentially pandemic viruses emerged as a cause of human disease in Hong Kong in 1997.

H5N1 has caused 381 human cases of influenza, with a mortality rate exceeding 60%. H5 strains have now been found in birds throughout much of the world (though not yet in the Americas), and human illness has occurred in 14 countries throughout Asia and in northern Africa.

The much-feared rapid spread through and between communities, however, has not occurred. Aside from small clusters of cases within families, each human case has been associated with close contact with poultry. The culling of poultry in the face of recognized bird disease has been a major defense strategy since the first outbreak.

In the article “Vaccine Preparedness – Are We Ready for the Next Influenza Pandemic?” Peter F. Wright tries to answer the question where we stand with vaccines against emergent influenza strains. He concludes that at this moment we are not ready to put a vaccine in the field should H5 gain person-to-person transmissibility or should another strain emerge.