Letter written to the Daily Post, Cardiff, 12th March 2006 for publication by Dr Chris Ashton.
Dear Daily Post,
I am really worried about the apparent lack of activity by DEFRA in establishing an effective vaccine bank to combat avian influenza.
The current scare about avian influenza is resulting in hardship for both bird owners and birds. Responsible owners worry about protecting their birds; irresponsible people discard them. Large numbers of 'pet' birds are now being dumped at animal sanctuaries, veterinary surgeries, or just plain culled due to fears about bird flu. Of course, there is no bird flu in the UK at present. It may not get here this year, but it might. DEFRA should have a vaccine bank in place for that eventuality. France and Holland have already achieved that.
If DEFRA would be more public about its current arrangements for vaccinating zoo birds, people would be more confident about vaccination. The TV news versions on vaccination have been biased and sometimes incorrect. The vaccinated commercial chicken flock which supplies Hong Kong with poultry meat has been completely successful in excluding disease. So why not use this vaccine with pets and free range breeds kept in close proximity to their owners? The advantage of allowing this now is, that if bird flu does strike, birds (and therefore their owners) are already protected, rather than having to wait 18 days until the first vaccination takes full effect. Birds also need a booster vaccination to give them immunity for a year. Emergency vaccination (with a single dose) is never as good as the full course of two doses. Besides there will not be enough time or personnel to administer the vaccine in time.
This may seem to be a lot of trouble but, unlike commercial chickens which live for six weeks, pet and free range birds can live to over 20 years in the case of geese, and even longer in other species. Why should their owners not have the choice to protect them? At present, big business is deciding what should happen to birds which have nothing to do with the commercial, export food chain.
DEFRA tells us that vaccinated birds shed virus and are a danger. Research and practice in Hong Kong demonstrates otherwise. All Hong Kong commercial birds are vaccinated, and there has been no avian influenza case in those birds, or sentinel birds, since vaccination began over three years ago. An Avian Pathology research paper (2004, Ellis et al.) shows complete efficacy.
Of course, no vaccines are 100% perfect. David Swayne is publishing a challenge experiment with chickens vaccinated with Intervet’s H5N2 vaccines from Mexico and Spain. The vaccines were shown to protect completely against mortality and morbidity. While all non-vaccinated birds excreted large amounts of virus, the majority of vaccinated birds did not excrete any virus. The minority excreted 10,000 to 100,000 times less virus than controls.
Similar results were obtained in the 2004 Animal Sciences Group, Wageningen University, experiment with wild ducks and H7N7. If the vaccine did not give complete protection, shedding was so small that infection of other birds did not take place.
As I perceive it, DEFRA has a duty to protect our rare and pure breeds of poultry under the National Farm Animals Genetic Resources initiative. This is an FAO and OIE requirement. However, merely listing our rare and traditional breeds will not be enough preserve them. We have to be proactive. This means our adopting a conservation policy rather than a cull policy in the event of an H5N1 outbreak in birds.
The cull policy is centuries old. Millions must have been spent already on research and development into the bird flu virus and vaccines. Hong Kong, Italy and Mexico have used vaccines successfully, and these are advocated by experts in the field such as Ilaria Capua, cited in the 4th March 2006 edition of the New Scientist.
DEFRA is being obtuse. The argument ‘to vaccinate or not to vaccinate’ is about risk. Which risk is more serious: to leave birds unprotected to infect humans, or to reduce risk and infection? In addition, why should anyone want to work in the poultry industry with unprotected birds? If the virus were to be introduced by the wild bird population anyway, how could your vaccinated birds be a risk to you? People should have the choice of vaccination for their pet and free range birds now. DEFRA's idea that free-range birds can be housed for months and months in buildings that are only designed for overnight protection is not feasible.
Christine Ashton (Dr)
Author of 'Domestic Geese', co-author of 'The Domestic Duck' by Crowood Press
Co-author of 'The Indian Runner Duck - a Historical Guide; 'Ducks' a colour genetics booklet; 'Calls and other Bantam Ducks'.
Contributor to the magazines Smallholder, Country Smallholding, and Fancy Fowl.
1. Ellis TM et al. ‘Vaccination of chickens against H5N1 avian influenza in the face of an outbreak interrupts virus transmission’. Avian Pathology, 2004, 33(4):405–412.
2. David Swayne (Southeast Poultry Research Laboratory, USDA/ARS, Athens, Georgia. US) is publishing a challenge experiment with SPF chickens vaccinated with Intervet’s H5N2 vaccines from Mexico and Spain.The results are being published, and a summary is available at www.avian-influenza.com. [This follows Swayne’s earlier published work: ‘Efficacy of vaccines in chickens against highly pathogenic Hong Kong H5N1 Avian Influenza.’ David Swayne, J. Beck, M. Perdue & C. Beard. Avian Disease, 45 (2), April 2001, pp 355-365].
3. ‘Transmission of Avian Influenza (H7N7) in vaccinated and unvaccinated pheasants (Chrysolophus pictus) and ducks (Callonetta leucophrys)’
Animal Sciences Group Wageningen University and Research Centre Report ASG05/I01764. ASG project 2042110000-1 October 2004 –September 2005
Michiel van Boven1, Jeanet A. van der Goot, Elly Katsma1, Guus Koch & Mart C.M. de Jong Animal Sciences Group, Lelystad, The Netherlands.