ZURICH — Manufacturing capacity and ingredients shortages are the main bottlenecks to expanding coronavirus disease 2019 (COVID-19) vaccine production, several global drug groups said on Tuesday, not patents that some critics are demanding be removed.

“IP (intellectual property) rights is not the issue,” said Thomas Cueni, who heads the International Federation of Pharmaceutical Manufacturers and Associations (IFPMA).

“The bottlenecks are the capacity, the scarcity of raw materials, scarcity of ingredients, and it is about the know-how.”

Mr. Cueni, who represents large drugmakers, spoke after a virtual meeting organized partly by the World Health Organization-backed COVAX vaccine sharing program. It included manufacturers, suppliers, and international organizations seeking to boost vaccine supplies.

IP protections are being fiercely debated during the pandemic. Activists, including those from Doctors Without Borders, are pushing for temporary patent waivers on certain COVID-19 technologies, while accusing rich countries of blocking vaccine production in poorer nations.

On Wednesday, World Trade Organization member states open talks on a joint proposal by India and South Africa to waive such IP rules.

Mr. Cueni’s group, and many developed nations, oppose such steps.

Others in the two-day supply chain meeting also contended that freeing up IP for vaccines was a far different proposition than compulsory licenses issued decades ago for simpler, small-molecule drugs including treatments for HIV/AIDS.

Complex vaccines have hundreds of ingredients, from lipids to encase messenger RNA to modified viral vectors to deliver DNA.

Giving away IP will not solve these challenges, said Rajinder Suri, chief executive of the Developing Countries Vaccine Manufacturers Network.

“There are so many issues which one has to really understand before getting into the tech transfer,” Mr. Suri said.

With the push on for 10 billion-plus COVID-19 vaccine doses in 2021, manufacturers and suppliers—and governments tempted to block exports—must coordinate and cooperate to avoid stumbling over each other, said Richard Hatchett, who leads the Coalition for Epidemic Preparedness Innovations (CEPI).

The meeting’s focus, Mr. Hatchett said, “was sorting out that problem and trying to create awareness among the different stakeholders about how we can successfully navigate these bottlenecks … rather than a conversation which was principally around intellectual property.”

“That’s not the acute problem,” he said. — John Miller and Stephanie Nebehay/Reuters