Canada (search) may have more than 2 million doses of surplus flu vaccine (search) to help the United States battle a serious shortage, health officials said Monday, although U.S. officials have cautioned that imports were unlikely to be licensed in time for this flu season.

A Canadian manufacturer has more than 1 million extra doses and as many as 1 million other doses could become available, depending on Canadian demand, said David Butler-Jones, Canada's public health officer.

The United States will not find the 48 million doses it needs but may get enough to vaccinate high-risk patients, Butler-Jones said.

Health Minister Ujjal Dosanjh (search) also said Canada has an "adequate supply for our needs" and is willing to share.

"If there is anything we can spare for our American neighbors and friends in a way that doesn't jeopardize the safety and supply for Canadians, we would do so," Dosanjh said.

The U.S. Food and Drug Administration is in discussions with two companies that sell flu vaccine in Canada and elsewhere, and have found a few million unsold doses, but that vaccine is not licensed for sale in the United States.

U.S. Health and Human Services Secretary Tommy Thompson cautioned earlier this month that meeting FDA requirements in time for this flu season "is doubtful."

The U.S. vaccine crisis began when British regulators shut down shipments from Chiron Corp., which had made 48 million flu shots in an English factory that were destined for the United States. Some batches of the vaccine were contaminated with a bacteria.

The surprise decision cut the U.S. supply of flu shots almost in half. The government is urging healthy adults to skip the shot this year so the 55.4 million available doses can go to the youngest, oldest and sickest Americans most vulnerable to influenza.

Butler-Jones said pharmacists and doctors in border areas should consider individual risk when deciding whether to sell vaccine to U.S. customers.

Meanwhile, a coalition of Canadian groups representing seniors, pharmacies and patients warned Monday that Canada cannot afford to continue to address U.S. drug shortages and soaring prescription costs with its own stocks.

The groups, claiming to represent 10 million Canadians, said Canada must stop U.S. citizens from using Internet pharmacies to raid Canada's medicine chest or face a drug shortage.

They called on Ottawa to ban prescription drug exports.

"It is completely untenable to think that Canada could supply their needs and our own for even one month, let along on an ongoing basis," said Louise Binder of the Canadian Treatment Action Council and Best Medicines Coalition.

Canada regulates drug prices and many American-made pharmaceuticals are available for far less than in the United States.