WASHINGTON (Reuters) - Chancellor Gordon Brown said on Monday there was increased government interest in advance purchases of a new malaria vaccine being tested by GlaxoSmithKline Plc to boost supply.

"We, Britain, are ready to come behind this and I believe there are other countries willing to do this," Brown told reporters on a conference call after receiving a Commitment to Development Award, co-sponsored by the Washington-based Center for Global Development and Foreign Policy Magazine.

He said Italy's Economy Minister Domenico Siniscalco had also expressed an interest in pursuing advance purchases of the vaccine, which could protect a large proportion of African children against the mosquito-borne disease.

Malaria sickens up to 500 million people each year and kills between one and three million, most of them African children under five.

In a study involving more than 2,000 children in Mozambique aged one to four, the vaccine proved 30 percent effective in preventing all cases of malaria. However, it reduced the risk of getting life-threatening forms of the disease requiring hospital treatment by 58 percent -- enough to save many lives.

Results from the intermediate Phase II study were published in The Lancet medical journal, based on six months follow-up after administration of three monthly injections.

Longer studies are now needed to prove the effect does not wear off and that there is no interference with other childhood shots, before final Phase III trials in infants get underway.

Those pivotal tests are likely to be conducted in six to eight African countries.

Brown said governments would shortly examine the issue closer.

"We have a conference involving a number of countries happening very soon to examine just what government can do in the field of financing research and advance purchase agreements," said Brown.

"So progress is being made here (and) again I hope we are in a position to make some announcement soon."

In conversations with the GlaxoSmithKline, the company acknowledged if the next stage of clinical trials were successful it would be ready to make available advance purchases to ensure quick supplies, he said.

Research for the vaccine was funded by charitable groups including the Bill & Melinda Gates Foundation.

"We're very impressed with the initial findings of the research," Brown said. "It does seem to be possible that we have this breakthrough in medicine that people did not seem to anticipate," he added.

Brown's remarks come as the World Bank said focus on HIV/AIDS had taken attention away from the battle against malaria.

The development bank on Sunday launched a new booster program to combat malaria that will include additional funding and seek out public-private partnerships to help with distribution of bed nets and anti-malaria drugs.

The Bank said there was already interest in the project from the Gates Foundation, Exxon-Mobil Foundation and the U.N Foundation.

It said it will submit to donors within the next two to three months a draft of the program, which still needs to be approved by the bank's executive board.