Eight other countries -- Australia, Brazil, Britain, France, Italy, New Zealand, Norway and Switzerland -- said they will make similar donations. Two vaccine manufacturers, Sanofi Aventis and GlaxoSmithKline, had previously said they would donate a total of 150 million doses. Worldwide production of the vaccine is projected to be more than 2 billion doses, but experts had feared that most of those doses would go to the rich countries, which could afford to pay for them. Those fears were eased last week when results from the first clinical trials of the vaccines showed that only one dose was required to stimulate effective immunity. That had the effect of doubling the available number of doses because experts had been assuming that two doses of vaccine would be required. The WHO has not yet said how it will distribute the vaccine. 