Millions of children are still at risk of dying from diseases like tuberculosis and measles even though vaccines are available to protect them.

A major international report shows that three out of four children around the world now have access to essential vaccines, which can potentially save their lives.

However, the vaccines are only available to half of those living in sub-Saharan Africa.

Today, no child should die from a vaccine-preventable disease

Carol Bellamy, Unicef

The report by the World Health Organization, Unicef and the World Bank, calls for urgent action to ensure those who need vaccines most can access them.

It warns that old diseases like tuberculosis, which have previously been under control, are flaring up again because of poor vaccination policies.

It adds that other diseases like rubella and hepatitis B are still claiming lives in some parts of the world because vaccines are too expensive.

Poor access

The report says that in some of the poorest and most isolated areas of the planet just one in 20 children is vaccinated against life-threatening diseases.

Carol Bellamy, executive director of Unicef and chairwoman of the Global Alliance for Vaccines and Immunization, said urgent action is needed.

"Vaccines are among the most cost effective public health interventions," she said.

We need to act fast and effectively to ensure that children and adults everywhere have access to life-saving vaccines

Dr Gro Harlem Brundtland, WHO

"Today, no child should die from a vaccine-preventable disease. We need to invest more - and more rationally - in vaccine coverage and research and ensure access in all corners of the globe."

Dr Gro Harlem Brundtland, director-general of the World Health Organization, warned that a failure to act would leave people at risk of major epidemics.

"We need to act fast and effectively to ensure that children and adults everywhere have access to life-saving vaccines.

"From a global perspective, this is the only way of avoiding major epidemics of new and old diseases."

Government aid

The report, entitled The State of the World's Vaccines and Immunization, calls for more government aid to help improve the situation.

It also urges governments in developing countries to give public health a higher priority.

It suggests that the failure of some governments to introduce vaccination programmes has left pharmaceutical companies without a market for many of their vaccines. As a result, few are willing to invest or research in new treatments, it adds.

Daniel Tarantola, director of vaccines and biologicals at WHO, said extra money was part of the solution.

"While new initiatives to fight killer diseases abound, it is the hard cash that is missing," he said.

"The global campaign for access to medicines and vaccines needs to be backed with political and financial commitment if we want it to get beyond words and make a difference to people."

James Wolfensohn, president of the World Bank, backed better cooperation between governments and pharmaceutical companies.

"A long-term vision and a plan of action are needed by governments, donors, the private sector and civil society.

"Through such strategic partnerships, it is possible to immunise every child."