Baxter International Inc. (BAX) is talking to the World Health Organization about potentially developing a vaccine against swine flu, and it could take about 12-16 weeks to provide the first doses once the manufacturing process starts, a Baxter spokesman said Wednesday.

That timeline is based on the idea that this strain may be similar to prior pandemic strains, although Baxter has yet to study the strain behind the current outbreak. Before the company starts actually making a vaccine, it must evaluate the virus' growth characteristics with the company's cell-based technology, a process that will take three to four weeks, spokesman Christopher Bona said.

First, Baxter needs to get its hands on a swine-flu sample. But the U.S. Centers for Disease Control and Prevention should start providing samples to vaccine-making companies within the next couple of days, Bona said.

"When we get the strain, Baxter will immediately begin evaluating and testing," he said.

It is unclear what role a possible Baxter vaccine could play in the U.S., where Baxter's cell culture-based pandemic vaccine for avian flu remains in clinical trials and isn't approved. But European regulators cleared Baxter's vaccine - called "Celvapan" - in such a way in December that should allow for quick retooling and then fast-track approval for fighting other flu strains.

Baxter used "vero cell technology" to produce vaccines in a method that doesn't require growing modified viruses in chicken eggs, a traditional method that can slow the process.

Baxter isn't the only company looking into the potential of making vaccines to fight the outbreak. Sanofi-Aventis SA (SNY) Chief Executive Christopher Viehbacher told The Wall Street Journal Wednesday that the first doses of swine-flu vaccine could be available about 15 weeks after the WHO decides what kind of vaccine it wants. He said Sanofi, a big vaccine maker, was waiting for the WHO and CDC to pick the strain that would work best in a vaccine.

Bona said Baxter will be part of a WHO vaccine-supply group that will meet weekly.

While health athorities and vaccine makers sort out potential methods to stop people from getting swine flu, health authorities have confirmed that two flu treatments - Roche Holding AG's (ROG.VX) Tamiflu and GlaxoSmithKline PLC's (GSK) Relenza - are effective against this virus.

Shares of Baxter recently traded down 2 cents to $49.66.

-By Jon Kamp, Dow Jones Newswires; 617-654-6728; jon.kamp@dowjones.com