Millions of children and teenagers in poor countries may soon be vaccinated against seven common diseases, health officials said Wednesday.

Officials at GAVI, formerly known as the Global Alliance for Vaccines and Immunization, announced they would start buying large quantities of vaccines to fight cervical cancer, cholera, typhoid, meningitis A, rabies, Japanese encephalitis and rubella. The vaccines will go to the world's 73 poorest countries.

"This could save a lot of lives," said Dr. Selina Lo, medical coordinator for Medecins Sans Frontiere's Access to Essential Medicines campaign. "These diseases do kill many children, so vaccines against them are very welcome in the developing world."

GAVI is a public-private partnership including UNICEF, the World Health Organization, vaccine industry representatives, and the Bill and Melinda Gates Foundation, among others. It buys vaccines for children and is also helping to develop new ones for diseases like malaria and dengue fever.

Since its inception in 2000, GAVI has bought vaccines for millions of children to protect them against diseases including hepatitis B, diphtheria, tetanus and whooping cough. It has prevented nearly 3 million child deaths and protected about 176 million children from getting sick, according to their figures.

The organization's board met Wednesday in Geneva to decide which diseases to tackle next.

Their decision was made primarily by considering which diseases kill the most children and primarily afflict the poor, said Andrew Jones, a GAVI vaccines expert.

Experts calculated that by vaccinating children and teenagers against the seven chosen diseases, almost 2 million lives of women and children could be saved in the next dozen years.

A further 27 million cases of the various diseases would also be averted, GAVI said.

GAVI will also work on cutting the costs of the vaccines, particularly those for cervical cancer, which is widely available in the West for about US$360 (230 euros) for a three-shot dose. Versions of the vaccine are made by GlaxoSmithKline PLC, Merck & Co. and Sanofi-Aventis SA.

"This is very much a work in progress," GAVI spokeswoman Nicole King said. "Our next step is to work on pricing and to work with countries on how to roll it out."

Countries eligible for vaccines sponsored by GAVI apply for consideration, and must tell the agency how they plan to deliver the vaccines, often with the help of UNICEF and WHO.

Countries are also asked to pay a small amount of the vaccines' cost, depending on their financial status.

Jones said that if all goes well, the first deliveries of meningitis A vaccines could arrive in countries by the end of the year, though the other vaccines are not forecast to be available until 2010. GAVI's board will meet in October to discuss implementation plans.

But delays in vaccine delivery are possible. GAVI had also intended to deliver vaccines against pneumococcal disease and rotavirus by this year, but has yet to come through, according to Dr. Orin Levine, an associate professor at Johns Hopkins Bloomberg School of Public Health.

Levine directs a pneumococcal vaccine initiative funded by GAVI, and was hopeful the vaccines might be ready soon.

That kind of slowdown worries officials working on the ground. "You can make all the commitments you want and you can invest billions of dollars into vaccines," Lo said. "But if they are not being rolled out for years, what does that mean for the children who are dying on the ground now?"