Four countries plan to unveil a unique $1.5 billion program tomorrow to fund Third World vaccines, an effort that may directly benefit Philadelphia-area firms GlaxoSmithKline P.L.C., Merck & Co. Inc., Wyeth and Sanofi Pasteur, officials said.

The United States is not participating in the pilot program, which springs from years of debate and frustration over the drug industry's retreat from unprofitable Third World markets, where millions of children die of preventable diseases every year.

Vaccine makers, ironically, are thriving in high-profit markets by charging unprecedented high prices for new vaccines. But those costly vaccines are even less accessible to poorer countries.

The Advanced Market Commitments for Vaccines program, it is hoped, will create viable markets for profitable vaccine sales in specific poor countries, rather than just giving free or subsidized vaccines to governments or agencies for distribution.

Its launch is the second new initiative by wealthy countries - not including the United States - to address the Third World vaccine crisis. In November, the United Kingdom led formation of a new financing organization that hopes to sell $5 billion in bonds to finance vaccine purchases and distribution.

Combined, the new programs could inject $6 billion or more in coming years into vaccine development and marketing, with direct benefit to the handful of firms dominating the vaccine business as well as new ones.

The program's first vaccine target will the pneumococcal virus, which can cause pneumonia and meningitis and is blamed for at least 1 million childhood deaths a year, according to the World Health Organization.

There are only two vaccines currently: Prevnar made by Wyeth of Collegeville, and Pneumovax 23 made by Merck of West Point. Neither vaccine, however, has been marketed extensively in the developing world.

"This is an attempt to accelerate by years, or a decade or more, the availability of vaccines for developing countries," said Jim Connolly, the Collegeville-based executive vice president of Wyeth's vaccine division.

"What it does, this potential source of money, is allows us to think about investing in additional manufacturing capacity" for current vaccines.

Wyeth is already working on a next generation of its vaccine, designed to block more types of pneumococcal infection. Merck declined to say if it would pursue a new pneumococcal vaccine, but added that the Advanced Markets Commitments for Vaccines was encouraging.

London-based GlaxoSmithKline, whose vaccine operation is based in Belgium, said it has a pneumococcal vaccine, Synflorix, in late-stage development and will consider seeking help from the advance-market program to support marketing in developing countries.

"We're clearly looking at that option," said Ken Inchausti, a spokesman in Philadelphia. "We want to see that there's a mechanism in place to move products forward."

Organizers say the new program could save 5.4 million lives a year if applied to all diseases.

The new program is being organized under the auspices of the G7 with the help of the GAVI Alliance, a nonprofit group created by the Bill and Melinda Gates Foundation.

According to GAVI officials, the announcement will be made by Italy, Britain, Canada and Norway. The World Bank, led by its American director, Paul Wolfowitz, will take part in the announcement, GAVI said.

Contact staff writer Thomas Ginsberg at 215-854-4177 or tginsberg@phillynews.com.