Some clinical trials of swine flu vaccine are underway
The first swine flu vaccines are likely to be licensed for use in the general population in September, the World Health Organization has announced.
Several manufacturers have produced initial batches of a H1N1 vaccine and some clinical trials are already underway.
WHO director of vaccine research Dr Marie-Paule Kieny also sought to calm fears about safety of new vaccines.
She said the vaccines were based on "old and proven technology".
Figures show continuing rises in cases in the southern hemisphere in the past seven days.
Argentina has particularly seen a large increase and deaths now stand at 337.
And there has been a rise in cases of 25% in Australia.
INCREASE IN PAST WEEK
China (Hong Kong) 46%
China (mainland) 16%
Although it has not yet been clarified who would be first in line for a vaccine, it is likely to be those who are most vulnerable, such as pregnant women and young children.
Some experts have raised concerns about the lack of safety data on flu vaccines in these groups.
In particular, a very rare neurological condition called Guillain Barre syndrome affected 500 people during a US vaccine programme against swine flu in 1976.
Dr Kieny said much was known about flu vaccines in these groups from seasonal vaccines given every winter and added that regulatory agencies would be monitoring for any signs of adverse reaction.
"The quality controls on today's vaccine are much better than they were 30 years ago," she added.
Regulators in the US and Europe have special plans in place to fast-track swine flu vaccines, some of which are based on conventional seasonal flu vaccines and some which use newer technology.
Clinical trials are already underway in China, Australia, USA, UK, and Germany.
It comes as drug company, Baxter, has announced the production of the first commercial batches of its swine flu vaccine Celvapan.
The vaccine has been grown using cell culture, a much faster method than the traditional way of growing it in eggs.
Baxter is one of two companies contracted to provide pandemic flu vaccine to the UK, the other being GlaxoSmithKline, and both plan to start clinical trials this month.
One key part of the trials is to work out whether people need one or two doses of the vaccine.
Ministers have repeatedly said they expect to have enough doses for half the UK population by the end of the year.