LONDON and NEW YORK — GlaxoSmithKline and Pfizer have signed long-term pacts to supply pneumococcal vaccines to developing countries.

Under 10-year agreements with the public-private GAVI Alliance announced Tuesday, GSK will supply up to 300 million doses of Synflorix, its vaccine for invasive pneumococcal disease, while Pfizer will provide Prevenar 13, its 13-valent pneumococcal conjugate vaccine, for infants and young children.

Pneumococcal disease is a leading cause of death in children under age 5 in developing countries, according to the pharmaceutical companies.

The agreements are funded by a novel mechanism called an Advance Market Commitment (AMC), a result of years of planning by GAVI, UNICEF, the World Bank and major donors to help provide vaccines to prevent diseases in developing countries. The AMC is backed by the G8 and was officially launched last June.

The supply pacts for pneumococcal vaccines have been financed by GAVI, five donor countries — the United Kingdom, Canada, Russia, Norway and Italy — and the Bill & Melinda Gates Foundation. By guaranteeing the availability of initial purchase funds, the AMC allows vaccine makers to invest in development and manufacturing capacity. Also, by contracting significant volumes over the long-term, manufacturers can slash the cost of their vaccines. Pneumococcal vaccines will be supplied at about a 90% reduction of the cost in developed markets, according to GSK.

In the AMC pneumococcal disease pilot, the governments of those five nations and the Gates Foundation committed $1.5 billion, with GAVI promising to allocate $1.3 billion through 2015.

"The coalition that has made this possible is providing new means to transform global public health," GSK chief executive officer Andrew Witty said in a statement. "The AMC is precisely the sort of innovative model needed to accelerate access to vaccines for people living in the poorest countries. The typical 15- to 20-year ‘vaccine gap’ between access in developed countries versus the world’s poorest countries is unacceptable. This AMC means children in Africa will start to receive Synflorix this year."

Pfizer noted that the AMC is designed to create a sustainable marketplace, ensure a stable supply of pneumococcal vaccines and stimulate the development and expansion of manufacturing capacity of vaccines for the world’s poorest nations.

"Pfizer is dedicated to broadening access around the world to our medicines, and public-private partnerships such as the one involving the AMC are critical to achieving true inroads on this front," commented Pfizer chairman and CEO Jeffrey Kindler. "Last year, working with GAVI, we contributed the first pneumococcal conjugate vaccine used in a national immunization program in the developing world, and we are proud to extend our commitment even further to young children in the world’s poorest countries by participating in the AMC."

To meet the rising global demand for Prevenar 13, Pfizer said it’s increasing its manufacturing capabilities to help ensure product supply through a combination of capital investment, process improvements and efficiency measures throughout the supply network.

Over the 10-year period of the agreement, GSK said it will supply up to 300 million doses of its pneumococcal vaccine, valued at approximately $1.3 billion. And over the next decade, the company has committed to provide an average of up to 30 million doses annually, starting with more than a million doses in 2010.