UNICEF is for the first time publicizing what drugmakers charge it for vaccines, as the world’s biggest buyer of lifesaving immunizations aims to spark price competition in the face of rising costs.

On Friday, UNICEF posted on its website the actual prices that it has paid individual drugmakers for 16 vaccines purchased over the last decade. It’s a move that a few Western pharmaceutical companies don’t support. Novartis AG and Merck & Co., which sells only one of its many children’s vaccines to UNICEF, both declined to have their prices published.

UNICEF said it will continue to disclose pricing of future vaccine deals, with the hope that the transparency will push drugmakers to cut prices and thus allow the organization to vaccinate more children and save more lives.

“Transparency will also help foster a competitive, diverse supplier base,” said Shanelle Hall, director of UNICEF’s supply division.

She noted that it also will help UNICEF’s partners and those governments that buy vaccines on their own to make more informed decisions in price negotiations with drugmakers.

UNICEF last year spent $757 million to provide 2.5 billion doses of vaccines to 99 countries, reaching an estimated 58 percent of the world’s children.

Its price list shows significant disparity, with Western drugmakers often charging UNICEF double what companies in India and Indonesia do.

Just as striking is the steady rise in prices in the last decade, with the cost of vaccines against measles, polio and tetanus roughly doubling between 2001 and 2010. Prices of a few vaccines have remained flat or declined as additional competitors entered the market.

There’s also a huge spread in prices among various vaccines.

As might be expected, shots that have been around for some time and those vaccines made by multiple companies cost just pennies per dose, such as tetanus and tuberculosis shots and oral polio vaccine. But a combination shot for immunization against diptheria, tetanus, whooping cough, hepatitis B and haemophilus influenza can run UNICEF $3 or more per dose. The dual vaccine against 10 or more strains of pneumococcal disease, which causes ear infections and meningitis, costs $3.50 a shot. And some of the vaccines require more than one booster shot, adding to the cost.

The cost is partly justified by the complex manufacturing process used to make combination vaccines. And UNICEF still pays far less than the $71 and $114 per dose, respectively, that is charged in the U.S. for those two vaccines. But given that the organization’s mission is to immunize entire populations of at-risk children, any savings means more kids can be vaccinated.