Britain says vaccine made its eggs safe

DES MOINES, Iowa - Low-cost vaccines that may have helped prevent the kind of salmonella outbreak that has led to the recall of more than a half-billion eggs have not been given to half of the nation's egg-laying hens.

The vaccines aren't required in the United States, although in Britain, officials say vaccinations have given them the safest egg supply in Europe. A survey conducted by the European food-safety agency in 2009 found that about 1 percent of British flocks had salmonella compared with about 60 to 70 percent of flocks elsewhere in Europe, said Amanda Cryer, spokeswoman for the British Egg Information Service.

There's been no push to require vaccination in the United States, in part because it would cost farmers and in part because advocates have been more focused on more comprehensive food-safety rules, those watching the poultry industry said.

But Darrell Trampel, a poultry veterinarian at Iowa State University, said vaccination would become more common after the recent outbreak. "I think [vaccination] will move from hit and miss to being a standard," Trampel said.

The salmonella vaccine prevents chickens from becoming infected and then passing the bacteria on to their eggs. It has been available in this country since 1992.

There are two forms: One is a spray that uses a live bacterium, and chickens inhale it. The other contains dead bacteria that are injected. Jewanna Porter, a spokeswoman for the Egg Safety Center, an industry group, said both forms provided good protection. The injected vaccine lasts longer, but veterinarians recommend that both be updated.

The Food and Drug Administration said last month that it did not believe mandatory vaccination was necessary, but it supports farmers doing it voluntarily.

Data on the vaccine's effectiveness in field trials conducted in real-world conditions were "insufficient to support a mandatory vaccination requirement," the agency said in the text of new rules requiring increased inspections and testing of eggs.

Doug Grian-Sherman, senior scientist at the Union of Concerned Scientists, said the vaccine deserved additional study, but it would likely have only have limited effectiveness against a bacterium like salmonella, which has many different strains.

"It's only going to be a Band-Aid on a much bigger problem," he said.

It would be more effective to give the FDA additional authority to stop repeat offenders and pull contaminated products off shelves and to move away from big production facilities that ship across the nation and can quickly spread disease, Grian-Sherman said.

"The way we produce a lot of our food and meat and eggs in particular, has gotten to a scale where it's very difficult to prevent these problems," he said. "That needs to change, and we need to think about producing food on a scale that is better for the communities and safer for consumers."

Both farms involved in the recall vaccinated some of their chickens.

Julie DeYoung, a spokeswoman for Hillandale Farms, said the company began purchasing vaccinated laying hens in September 2009. The company did not vaccinate older hens but replaced them with vaccinated ones as they left production, she said.

"So about 80 percent of the hens have been vaccinated," DeYoung said.

The British government began encouraging, but not requiring, vaccination after a salmonella scare in the late 1980s crippled its egg industry. There was a 60 percent drop in egg sales overnight.