The race for a coronavirus vaccine has stoked a debate on how much the jabs will cost and who will pay for them, as prices range from $3 to more than $30 a dose and public health advocates including Bill Gates call for a price cap for poor countries.

Even as billions of dollars of public money has been poured into vaccine development, drugmakers have been reluctant to discuss how they will price a shot. They say it is the result of many factors including efficacy, trial results, development and manufacturing costs, competition, demand and whether the buyers are private groups — such as insurers — or state bodies.

The pandemic’s urgency and global spread has added layers of intricacy. In the rush to develop the right vaccine, companies are experimenting with different technologies. In an unprecedented move, some drugmakers are then planning to allow other companies to manufacture their doses, further complicating cost calculations.