Buried deep in the middle of a long article on poultry production and other farm news that appears on the website Poultry Indonesia, we get a fascinating glimpse at some of the debate going on over the vaccination of poultry against the H5N1 virus in Indonesia.
Vaccination of poultry, which has become a mainstay for prevention in countries like Indonesia, Vietnam, China, and Egypt has increasingly come under fire in the past year with the emergence of signs of asymptomatic H5N1 infection in domesticated birds.
The OIE (World Organization For Animal Health) recently reaffirmed their long-standing position that vaccination of poultry cannot be considered a long-term solution to combating the avian flu virus.
In Avian influenza and vaccination: what is the scientific recommendation?, the OIE reiterates their strong recommendation that humane culling be employed to control avian influenza, and advising that vaccines should only be used as a temporary measure.
While the OIE concedes that some nations may require the use of vaccines for `several years', they strongly urge that countries move away from that program and towards the more conventional culling policy.
Dr. C.A. Nidom is no stranger to regular readers of this blog. A virologist with the Tropical Disease Centre at Airlangga University, Dr. Nidom’s studies have often been highlighted in this column.
What follows is an excerpt from a much larger monthly report on the poultry industry in Indonesia (hat tip Florida1 at Flutrackers), where Dr. Nidom – a long standing opponent to poultry vaccination – makes his case for culling infected poultry instead.
Dr. Nidom’s views are not the only ones expressed in this report, and so you may wish to follow the link to read it in its entirety.
Chairul Anwar Nidom, a virologist with the Tropical Disease Centre at Airlangga University in Surabaya, said a common policy on bird flu was lacking among government agencies, making controlling the disease more difficult.
Nidom criticized the government’s policy of vaccinating poultry rather than culling, believing that it masks the virus, and ultimately contributes to its mutation.
“There’s still no common agreement on this issue among government agencies. The agriculture and farming sector sees the need for vaccinations to save the economy,” Nidom said. “We are at a crossroads, having to choose between saving poultry and protecting human beings. Frankly, we still don’t know exactly the virus’s pattern of infection and its predispositions,” he said. “As long as it remains so, it will remain a threat to humans.”
Nidom said that based on his research in 2008, the mutation model of the avian influenza virus has changed and is no longer considered common. “Poultry no longer die when infected by the virus, but become virus carriers. The virus has changed rapidly,” he said.
His finding were confirmed by poultry disease expert Charles Rangga Tabbu from Gadjah Mada University in Yogyakarta, who said the virus today has different clinical symptoms than the first one discovered in Tangerang, Banten Province, in 2003.
“The virus no longer shows specific clinical symptoms, making it more difficult to recognize,” Charles told Kompas newspaper in a recent interview.
The change in symptoms, he said, is due to a virus mutation, as well as from vaccinated poultry coming into contact with the virus.
Such poultry have weak antibodies as a result of being vaccinated, causing the virus to remain in their bodies and ultimately in their feces, said Nidom, who criticized vaccinations as part of the bird flu eradication program. “When human gets sick, the poultry shouldn’t be vaccinated. Let the poultry get infected by the virus and die,” he said.
“Vaccinations press the virus and keeps poultry from getting sick, but as a result, the virus is carried everywhere.”
(Continue . . .)
Countries like Egypt, Indonesia, Vietnam and China that rely heavily on vaccination as a means to control the H5N1 virus risk driving the mutation of the virus, and silently spreading the virus.
Culling is a difficult choice, of course, particularly in developing countries as it deprives poor (and often hungry) people of a relatively inexpensive source of food protein and income.
In order to be effective, culling must be combined with compensation.
Nevertheless, nations currently using poultry vaccines are likely to come under increasing international pressure to convert to more traditional control methods as time progresses.