As if it had crossed back over the mythical river Styx that surrounds Hades and separates the living from the dead, the stock of Chiron (NASDAQ:CHIR) was brought back to life by British authorities who gave their approval for the company to begin production of its flu vaccine. The stock rose 6% on the news.

Chiron is the provider of half this country's flu vaccine supply. Its license to manufacture the vaccine was suspended when contamination was found and all 48 million doses it had produced had to be destroyed, sending health-care officials into a panic. Fortunately, the flu season turned out to be rather mild, and the shortages that marked the initial rationing of the remaining doses -- provided by Sanofi-Aventis (NYSE:SNY) -- dissipated.

The vaccine debacle damaged Chiron, though not permanently. Aside from the decline in its share price, which at one point had fallen some 30% or more off its highs, the snafu allowed other vaccine manufacturers a chance to enter the market. Going forward, Chiron might not be just one of a two-player field.

It's expected that Canadian upstart ID Biomedical (NASDAQ:IDBE) will be granted permission to sell a relatively small supply of its vaccine this year as it prepares to ramp up production for the following year's flu season. And the huge British pharmaceutical GlaxoSmithKline (NYSE:GSK) is preparing to enter the market in a big way in two years. Analysts project the two of them could sell as many as 20 million doses combined.

They may well find a receptive market. Distributors of the vaccine, such as Henry Schein (NASDAQ:HSIC), were caught flat-footed by the fiasco and took a $13 million charge because of it. Along with AmerisourceBergen (NYSE:ABC) and McKesson (NYSE:MCK), Henry Schein has signed on to distribute ID Biomedical's vaccine.

For Chiron, though, the lifting of the ban is indeed good news. CEO Howard Pien had thought the company would not have visibility on its ability to begin production until after this month, which would have been cutting it close to meeting the need for this year's flu season. It takes four to six months to develop the vaccine, and the decision now gives Chiron time to prepare its supply. Analysts predicted that Chiron would be able to make about 35 million doses this year, which should help offset the lost revenues and $91 million writedown it had to take last quarter.

Chiron's investors can breathe a sigh of relief that they won't be heading to the Elysian Fields any time soon.

Read the full coverage of the flu vaccine mess here:

Fool contributor Rich Duprey is sure the Elysian Fields have an endless supply of Krispy Kreme doughnuts. He does not own any of the stocks mentioned in the article.