WASHINGTON (Kyodo) -- British drug maker GlaxoSmithKline Plc. is suspending the use of 170,000 doses of its new H1N1 influenza vaccine in Canada given a higher-than-usual rate of reported side effects, Canadian media reported Monday.

Japan's Health, Labor and Welfare Ministry, which has a contract with the pharmaceutical firm to buy two-shot doses for 37 million people, will send a fact-finding mission to Canada by early December, health minister Akira Nagatsuma said in Tokyo.

Six cases of anaphylaxis, an allergic reaction causing breathing difficulties and reduced blood pressure, were reported after vaccinations in the Canadian province of Manitoba, but in all cases those inoculated recovered after a short time, according to the reports.

There are usually one or two reported cases of such side effects for every 170,000 doses, so the company has decided to examine the 170,000 doses with specific serial numbers, they said.

The Japanese health ministry was informed of the development by the company's Japanese unit, GlaxoSmithKline K.K., and is gathering information to determine if the problem is related to specific batches or the vaccine as a whole, ministry officials said.

With domestically produced new-flu vaccine in short supply, the ministry has said it will take the special step of allowing imported vaccines without formal clinical trials in December and will start vaccinating elderly people with no health problems in January.