Thursday, May 11, 2006

Here's three bits of hopeful news about bird flu:

1) H5N1, the influenza strain raging through bird world, has never caused a human epidemic.

2) French researchers have completed a phase I trial with a vaccine made from inactivated flu virus which infected humans in Vietnam in 2004. The immunization was well-tolerated and resulted in a good antibody response in volunteer injectees.

3) H5N1 prefers to attach to cells with surface receptor molecules known as sialic acid-alpha-2,3 Gal. How would we even know what kind of news that is? Because Rotterdam researchers assure us that cells with this receptor exist deep within the lungs, which makes the avian flu virus less easily spread from one human to the next via a cough or a sneeze.

Here, however, is the bad news:

1) The virus, while not loving those upper airway cells, definitely has a taste for the lower airway. "The virus readily attached to and proliferated within the bronchioles and alveoli." This attack plan "may contribute to the severity of the pulmonary lesion," the Dutch specialists concluded from their studies.

2) While the same authors point out that it would take a series of mutations to interest the H5N1 in the upper airway, they remind us that "recombination is the real concern on everyone's mind."

No comments: