Vaccines Could Boost Flu Risk

WIDESPREAD use of ineffective and fake animal vaccines may be greatly increasing the threat of a human flu pandemic, a leading expert said today.

Many vaccines given to poultry in bird flu hot-spots such as south-east Asia fail to control the virus, said Dr Robert Webster, from the World Health Organisation.

As a result, even in apparently healthy birds, the virus is allowed to spread and evolve into new forms.

With each new strain that develops, a new vaccine has to be designed to combat it.

In Asia, the potenti -ally deadly H5N1 virus has already split into as many as five different lineages.

If one of these evolved into a variety capable of transmiss -ion between humans, or combined with an established human flu virus, it could spark a devastating pandemic claiming millions of lives.

Vaccines work by using an “antigen” – a protein from the target virus – to switch on an immune respon -se.

Dr Webster said: “There are good vaccines and bad vaccines. Good vaccines reduce virus load; bad vaccines stop the signs of disease but the virus keeps replicating, spreading and evolving