The World Health Organization has declared the swine flu strain a pandemic, and it killed almost 1,800 people worldwide through last week. International attention has focused on how the pandemic progresses in southern hemisphere countries such as Australia, which are experiencing winter and their flu season.

It was not immediately clear if Australia would be the first country to administer vaccines. Health Minister Nicola Roxon said no formal announcement had been made elsewhere, but that she expected other countries to start programs at about the same time.

The U.S. government has predicted it would start distributing a vaccine in mid-October.

The first vaccinations will go to more than 4 million vulnerable Australians including pregnant women, handicapped children, health workers and the obese, Roxon said.

She said Australian drug maker CSL will deliver the first of 2 million doses to the government Aug. 31, but that safety tests from clinical trials are not yet complete.

"We are planning ... for the vaccination program to commence at some time in September," Roxon told reporters.

In Australia, the vaccine will first go to priority groups who make up more than 4 million of Australia's 21 million population - pregnant women, chronically ill, the obese, Outback Aborigines, handicapped children and health workers.

Clinical trials will determine whether one or two doses are needed to protect a person from the potentially fatal virus. Australia plans to buy 21 million doses.

"We were the first country to enter into clinical trials of mass vaccine and we'll be the first country to know how a vaccine program would best be structured as a result," CSL spokeswoman Rachel David said.

She said an interim report on those trials, which began July 22, will be delivered to the government next week.

She said she understood Britain planned to distribute a vaccine produced by GlaxoSmithKline, a local manufacturer, without clinic trials. A GlaxoSmithKline Australia Pty. Ltd. spokeswoman was not immediately available for comment Thursday.

CSL recently notified the United States that its shipments would arrive later than promised because it first must provide batches to the Australian government.

The United States won't have the long-promised 120 million doses ready to dispense by Oct. 15, but just 45 million instead, according to the latest estimates by the U.S. Department of Health and Human Services this week.

China has yet to announce a detailed swine flu vaccination strategy, but has previously said it is aiming to build a reserve of vaccine doses for 1 percent of the population, or 13 million, by October.

Last week, China's Health Ministry said all clinical trials were expected to be completed by mid-September.