Australia has scrambled to immunise its entire population against swine flu if necessary as Asia-Pacific's worst-hit nation responded to what one health official called an "unstoppable" pandemic.
The warning from the official with the UN's World Health Organization (WHO) came after Britain, Brazil, Colombia, Mexico, the Philippines and Thailand all reported new deaths on Monday.
Australia, where the A(H1N1) strain of influenza has infected almost 10,000 people and been linked to 19 deaths, said it was placing an advance order for 21 million courses of a vaccine that is now under development.
Six people younger than 40 who had otherwise been healthy remained on life support in Sydney after swine flu severely damaged their lungs, officials said.
Australia is already in the southern hemisphere winter, and officials fear the consequences if swine flu mutates into something deadlier in combination with the regular strain of influenza.
Bishop said 21 million doses would be enough to vaccinate everyone in Australia once over, or half the population if two courses were required, ahead of a "second wave" of infections.
South Korea has reported no deaths but is also ordering vaccines, in its case enough for 13 million people -- more than a quarter of the population.
The health ministry in Seoul said Tuesday it had confirmed an extra 40 cases of swine flu -- including 24 Indonesians who arrived last week to take part in a world choir competition. The contest has now been called off.
Densely populated Hong Kong, which was paralysed by an outbreak of Severe Acute Respiratory Syndrome in 2003, said this week it was buying enough swine flu vaccine to cover two million high-risk people.
With the global death toll from A(H1N1) now reaching at least 429, WHO director of vaccine research Marie-Paul Kieny said Monday that a swine flu vaccine should be available as early as September.
A group of vaccination experts had concluded that "the H1N1 pandemic is unstoppable and therefore all countries would need to have access to vaccines," she said at WHO headquarters in Geneva.
Although a vaccine is not yet available, Australia has commissioned pharmaceutical company CSL to manufacture one, following trials.
"We need to do some trials to make sure it's safe, so we're saying by October we should be able to start a programme, but that depends really on manufacture being successful," Bishop said.
A handful of pharmaceutical companies are racing to develop a vaccine against A(H1N1), which the WHO says has infected more than 94,500 people worldwide.
Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases in the United States, said last week that clinical trials on a first candidate vaccine were expected to begin next month.
The race for a vaccine is accelerating as governments worldwide brace for the northern hemisphere's return of the regular influenza strain, which kills many thousands every year.
A US study released this week warned that swine flu could pick up genes from other flu strains that would enable it to be both highly virulent and contagious, or become resistant to the anti-viral drug Tamiflu.
Health workers should be at the top of the list for vaccination because they will be in high demand as more people fall sick, the WHO's Kieny said.
Particular attention would have to be paid to children since they are considered "amplifiers" of the spread of the virus, especially when gathered in schools, she added.
Saudi Arabia Monday shut an international school in Riyadh after 20 students were diagnosed with the A(H1N1) virus.
Saudi officials are especially concerned over swine flu with upwards of two million people expected over the next five months on pilgrimages to the Muslim holy cities of Mecca and Medina.