Scientists have warned that they have met a major stumbling block in creating a vaccine for common food poisoning bug Campylobacter in chickens - after research revealed that the animal’s short life span is not long enough to generate an immune response to a jab against the bacteria.
Researchers from the University of Liverpool said they had found that the immune response of farmed chickens does not develop fast enough to fight off Campylobacter during their short lifespan, which cane be just six weeks in an average farmed chicken.
The bacteria, which is found at high levels in seven per cent of supermarket chickens, according to a recent study, is the leading cause of food poisoning in the UK and makes 280,000 people ill every year, causing symptoms such as vomiting and diarrhea.
A report out last week from the Food Standards Agency found that Marks and Spencer chickens were most likely to contain the bacteria with 9.5 per cent of samples having high levels of campylobacter. Any chicken with more than 1,000 “colony forming units” per gram of skin is considered high.
Professor Paul Wigley, from the University’s Institute of Infection and Global Health, said: “Our findings suggest that any Campylobacter vaccine relying solely on an antibody response is unlikely to be effective in broiler chickens.”
Researchers carried out the study by chemically inhibiting the production of antibody-producing white blood cells in broiler chicks, before introducing C.jejuni infection at the age of three weeks and then monitoring bacteria levels in the gut for the next nine weeks.
They found that an antibody-associated drop in bacteria levels only became apparent after seven weeks and suggest that the adaptive immune response in the gut only begins to mature at six weeks of age.
Professor Wigley added: “Vaccines that focus on a cell-mediated immune response, or alternatively some way of speeding up the production of antibodies in broiler chickens, may offer more promising routes to controlling Campylobacter, and ultimately reducing the amount of contaminated chicken in our supermarkets.”
Approximately four in five cases of Campylobacter infection in the UK result from contaminated poultry - either through consumption of undercooked meat or through cross contamination in the kitchen.