Avian flu vaccine may not arrest outbreaks

Vaccinating chickens against avian flu could lead to new strains that are a greater danger to humans, disease experts have warned.

Vaccinating chickens against avian flu could lead to new strains that are a greater danger to humans, disease experts have warned. The experts, from the United States and elsewhere, said the flu virus may be mutating in vaccinated chickens into a form that could spread through the human population, New Scientist magazine reported. The World Health Organization has said vaccination remains one of the most important ways of fighting the avian flu outbreak. By mid-March, the WHO had reported 12 confirmed cases in Thailand, of which eight were fatal. The current form of bird flu, called H5N1, can spread from birds to humans, but not from person to person. The experts warned, however, the virus probably is still circulating among vaccinated birds and could evolve into a form which can spread by human to human contact. This is because flu vaccines are not 100 percent effective and some viruses can replicate in animals’ or birds’ bodies and continue to spread in what health officials call silent epidemics. (Source: United Press International, March 2004)