Drugmakers on Thursday said U.S. President Joe Biden's support for waiving patents of COVID-19 vaccines could disrupt a fragile supply chain and that rich countries should instead share more generously with the developing world. Biden on Wednesday threw his support behind waiving intellectual property rights for COVID-19 vaccines, angering research-based pharmaceutical companies. If adopted by the World Trade Organisation, the proposal would invite new manufacturers that lack essential know-how and oversight from the inventors to crowd out established contractors, the International Federation of Pharmaceutical Manufacturers and Associations (IFPMA) said. "I have heard many (vaccine makers) talking about 'our resources are stretched, our technicians are stretched'," IFPMA Director General Thomas Cueni told Reuters. He warned of a possible free for all if "sort of rogue companies" were allowed to become involved. Vaccine developers echoed his comments that waiving intellectual property rights was not a solution.