Faced with a crisis more than a decade ago in which thousands of people were sickened from salmonella in infected eggs, farmers in Britain began vaccinating their hens against the bacteria. That simple but decisive step virtually wiped out the health threat.
But when American regulators created new egg safety rules that went into effect last month, they declared that there was not enough evidence to conclude that vaccinating hens against salmonella would prevent people from getting sick. The Food and Drug Administration decided not to mandate vaccination of hens — a precaution that would cost less than a penny per a dozen eggs.
Now, consumers have been shaken by one of the largest egg recalls ever, involving nearly 550 million eggs from two Iowa producers, after a nationwide outbreak of thousands of cases of salmonella was traced to eggs contaminated with the bacteria.
The F.D.A. has said that if its egg safety rules had gone into effect earlier, the crisis might have been averted. Those rules include regular testing for contamination, cleanliness standards for henhouses and refrigeration requirements, all of which experts say are necessary.
However, many industry experts say the absence of mandatory vaccination greatly weakens the F.D.A. rules, depriving them of a crucial step that could prevent future outbreaks.
