Beijing (AsiaNews/Agencies) – Vaccinating all poultry raised in China against bird flu "is impossible", experts say. The government announced on 15 November that it will vaccinate all poultry and, at the beginning of this week, it said 60% have already been vaccinated. At the moment, there are 5.2 billion chickens in breeding farms and 14 billion will be bred over one year.

Experts have highlighted considerable technical problems. Above all, "the problem is it takes so many people to implement the programme across such immense territory," said Leon Russell, president of the World Veterinary Association. "It is not possible to provide medicine with the feed as this does not work on birds. And even if it did, the residue would contaminate the poultry meat and make it dangerous to consume."

Chinese television has shown workers spraying whole coops at a time, but the Food and Agriculture Organisation (FAO) said it had not heard of cases where this method had proven effective. Each and every bird must be injected with the vaccine.

Using an automatic injector, "each person can vaccinate about 600 an hour", said J.J. Giambrone, professor of poultry health at Auburn University in Alabama. However, he added, even if China has plenty of cheap labour available, "vaccinating 14 billion birds in the field by hand would be almost impossible."

Another difficulty is that 70% of Chinese poultry is raised in backyard farms spread across the territory.

In Vietnam too, the government started to vaccinate poultry in September. There are around 220 million birds and the authorities said that within a short time, vaccination would be completed in 58 out of 64 provinces. Hoang Dang Huyen, head of the Animal Health Department in Bac Giang province, said veterinarians visit households with more than 200 poultry for vaccination, while people with fewer fowl have to travel to an agreed location.

Another obstacle is the timing and costs involved in producing the necessary vaccines. China said it could produce 100 million doses of the vaccine per day, a claim which Giambrone dismissed as "nearly impossible". He said the vaccines are made in specific pathogen free (SPF) eggs, but there are not enough SPF eggs in the world to produce that much vaccine. If China is using regular hatching eggs, they "may be contaminated with bacteria and viruses," and this means they run the "risk [of] contaminating all their poultry flocks".

The use of fake vaccines is a widespread problem in China. Du Qingling, Agriculture Minister, warned this month that "the use of fake and shoddy vaccines will result in a disaster" and that only the use of certified vaccines can provide immunity to the virus.

It has been observed that in the case of outbreaks of infection, China prefers to cull birds at risk rather than to vaccinate them. So far, according to the government, more than 21.1 million birds have been culled. This leads one to believe that vaccinations are either still incomplete or else not easily applicable. Said Russell: "The best thing is to stop the spread by destroying the flocks that have bird flu."

Meanwhile, despite the vaccination campaign, new outbreaks of infection are practically a daily occurrence now. Today, the Agriculture Minister reported another three in the northern regions of Xinjiang and Ningxia and in the southern province of Yunnan. Poulty within a 3km radius were culled, more than 8,000 birds in Xinjiang, 99,400 in Yunnan and 66,800 in Ningxia. Live poultry markets in Guangzhou and in Urumqi have been shut down, and Shanghai is expected to follow suit within days. The municipal government of Shanghai has ordered all hospitals to pinpoint and to monitor all patients with high fever. In Beijing, all those with temperature higher than 37,5 degrees Centrigrade are placed under observation.