Vaccination or mass slaughter?Defra has agreed to examine the potential of vaccination in fighting an AI outbreak.
The Soil Association has declared that while it accepts infected flocks will need to be slaughtered it then wants to see vaccine used as a tool to ring-fence affected farms or areas. Poultry vaccines already exist for the virus and are being widely used in Russia , China and Indonesia .
But Defra has taken a negative attitude to its use in Britain because the use of an inactivated vaccine means it must be injected. The SA believes that with adequate training, planning and stockpiling of vaccine the difficulties could be overcome.
Researchers have already reported the effect of vaccine used in Hong Kong in an H5N1 outbreak in December 2002. The virus struck wild birds, poultry markets and farms. Affected flocks were culled, biosecurity increased and vaccination used in unaffected sheds and farms. Although the virus did spread to vaccinated sheds, between 9 and 18 days after vaccination mortality was low and after this period no more deaths occurred.
Both the UN Food and Agriculture Organisation and the World Organisation for Animal Health have declared that the main method of controlling H5N1 should be vaccination. Their experts agreed that the mass culling of infected and at-risk livestock is no longer acceptable as the main method of control “for ethical, ecological and economic reasons”. Additionally, they recognise that this approach is not effective in the case of bird flu, since a reservoir of the virus persists in the wild bird population and the virus cannot be eradicated by slaughtering domestic birds.