Fortunately, there have been no reports of the flu yet in Maine and it looks like this will be a mild season for the illness that kills thousands of people a year. That’s good news since the country’s supply of flu shots was cut in half when problems arose at a British plant that made the vaccine. It is, however, no excuse for regulators not to step up their oversight of vaccine manufacturers.

Documents released this week show that the U.S. Food and Drug Administration dragged its feet when investigating problems and calling for fixes at the Chiron plant in England. Contamination at the plant, found by British inspectors, was so bad that the government yanked the company’s license, depriving the United States of 50 million expected doses of flu vaccine.

Contamination problems at the plant, owned by a California-based company, are nothing new, according to the documents, released in advance of a U.S. House Government Reform Committee hearing on the vaccine shortage. Con-tamination problems were found in 1999 and the FDA threatened to take legal action if they were not fixed. In 2001, FDA inspectors found 31 deficiencies at the plant. Twenty-six of them were rectified by a 2003 inspection, but 20 new ones, including high levels of contamination, poor sanitary practices and little effort to correct problems, were found. FDA inspectors recommended that the agency take enforcement action against Chiron. The agency requested voluntary compliance instead.

FDA officials told the House committee that the 2003 problems did not contribute to this fall’s closing of the plant. Acting FDA Commissioner Lester Crawford told the panel that the company did what the agency asked and that there was no need for further inspections. However, when British officials visited the plant in September they found contamination problems so egregious that they took away the facility’s license.

Even if the company did what the FDA asked, it is troublesome that the agency had to ask that deficiencies be addressed almost every year. It is even worse that the agency was slow to alert Chiron to problems it found and then relied on the company to fix them voluntarily. Ominously, the company’s CEO warned lawmakers this week that next year’s flu supply could be in jeopardy.

Contamination is expected in the early stages of vaccine making because strains of the virus are grown in chicken eggs before being extracted, blended and placed into vials. The latter part of the process is supposed to be sterile.

In addition to stepping up its oversight – and enforcement if necessary – the federal government should invest more money into supporting and advancing research into other

vaccine manufacturing techniques. Such research is under way, but is just starting.

A mild flu season is a blessing, but not a reason for a continued lack of vigilance.