The nationwide vaccination of poultry against bird flu in Vietnam has been halted as a new type of the H5N1 virus had rendered the vaccine ineffective the Vietnamese government has said.
The government said in a statement that a new type of the virus had appeared in 2010 following post-vaccination surveillance. Vietnam had planned to use a vaccine imported from China for its vaccination this year, but the vaccine did not work against the new variety, the Animal Health Department said.
The new type has been circulating in northern provinces, coastal provinces in the central region as well as in the Central Highlands, although it was reported that the old type of the virus remains active in southern provinces.
H5N1 virus in poultry was first detected in Vietnam in 2003 and health experts now fear that the disease could mutate to a form that could be easily transmitted between humans. Almost all of the human H5N1 infections to date are believed to have passed from birds to humans.
Vietnam has detected no human cases of bird flu in 2011 but several provinces across the country have reported outbreaks in ducks and chickens.
Source: Reuters India