For the first time, the United Nations Children's Fund (UNICEF) has published the prices it pays manufacturers for vaccines.

UNICEF is the world's biggest buyer of children's medicines, and vaccines is its largest procurement activity, worth $757 million last year. The new policy brings it into line with other procurement agencies such as the Global Fund to Fight AIDS, Tuberculosis and Malaria, which routinely publish the prices they pay for medical supplies, and UNICEF says it hopes to extend this new transparency to other purchases such as essential drugs.

The published list reveals considerable differences in the prices charged by different manufacturers, and observers are forecasting that donors will demand action to bring down the higher prices and that other procurement agencies will seek to obtain their supplies at the lowest prices obtained by UNICEF. A spokeswoman for the Fund was quoted by the New York Times as saying the decision to publish was made "in the hopes it will lead to a more competitive market and lower prices, especially for newer vaccines."

"Transparency is a core principle in itself and will support governments and partners in making more informed decisions," said Shanelle Hall, director of UNICEF's supply division. "Transparency will also help foster a competitive, diverse supplier base for global public goods," she added.

"Improved transparency on pricing is coming at a critical time, especially as vaccines against pneumonia and diarrhoea are being made available. The approach will soon he extended to other vaccine market dynamic factors, and other health products that are essential to child survival," said Ms Hall.

UNICEF notes that it undertook a consultation with all suppliers to ensure understanding and acceptance of the new policy prior to publishing vaccine prices on-line. All recent and future tenders include a clause that enables the organisation to make awarded vaccine prices publicly available, in addition to pricing and contracting information already in the public domain on UNICEF's website.

The New York Times also reports that a number of vaccines suppliers had been unhappy about UNICEF's requests to publish the prices it was paying them, but that by May 27, when the list was published, the only major company which to still be resisting was Novartis, which said it did not disclose pricing information on its vaccines because this information was competitive.

Helen Evans, interim chief executive of the Global Alliance for Vaccines and Immunisation (GAVI), which is the main funder of vaccines procured by UNICEF, said that transparency of pricing "enhances partners and countries' understanding of market dynamics, leading to better visibility of how their financial commitments translate into the number of children vaccinated and lives saved." 

However, last year, an evaluation of GAVI's work during 2006-2010 conducted by Cambridge Economic Policy Associates (CEPA) criticised the agency for not doing enough to reduce prices. In its response, the GAVI Secretariat said it agreed that "vaccine prices have not fallen far or fast enough," but that it had elevated market-shaping to the level of a strategic goal in its new strategy.

The Secretariat added, however: "it also needs to be recognised that some of the vaccines now in GAVI's portfolio are complicated to manufacture, and will not fall to the price of older vaccines in the near future."

• Last year, UNICEF provided 2.5 billion doses of vaccines to 99 countries, reaching an estimated 58% of the world's children.