Measles vaccines, invented 50 years ago, cost as little as 25 cents to produce. Ms. Elder said she believed HPV vaccines could be made for as little as $1 a dose. She acknowledged, however, that her only evidence of that was an unofficial estimate by Pan American Health Organization experts.

A spokeswoman for the organization declined to discuss its assessment of manufacturing costs because its own price negotiations are continuing.

Dr. Julie Gerberding, a former director of the Centers for Disease Control and Prevention who is president of Merck’s vaccine division, said $4.50 was Merck’s manufacturing cost, with no previous research, marketing or other costs built in.

“The price is what we calculate to be our cost of goods — we could be off by a few cents but not more,” she said. “As we expand volumes, the cost per unit can go down. Our intent is to sell it to GAVI at a price that does not bring profit to Merck.”

Glaxo declined on Wednesday to disclose its manufacturing costs, but noted that it had always been in first place on the Access to Medicines index, which was introduced in 2008 to measure how well pharmaceutical companies get their goods to the poor. A company representative said it would not make a profit on the vaccine at the new price.

Dr. Peter J. Hotez, president of the Sabin Vaccine Institute, said the vaccine should cost more to make than, for example, measles vaccine because it contains “viruslike particles” made through recombinant DNA technology rather than a virus simply grown in cells and then killed. Also, it protects against several HPV strains, while there is only one measles strain.

Dr. Berkley described the new prices as a ceiling, and said he expected them to go down as millions more doses were ordered and as rival vaccine makers from lower-cost countries like India and China entered the field. Other companies, including the Serum Institute of India, the world’s largest vaccine maker, are developing papillomavirus vaccines, but only the Glaxo and Merck vaccines now have approval from the World Health Organization.