Shares in Asia-listed vaccine makers tumbled Thursday after the US backed a plan for a waiver on Covid-19 patent protections in a bid to get the drugs to poorer countries struggling to inoculate their people.
Trade Representative Katherine Tai said Wednesday that the White House "supports the waiver of those protections for Covid-19 vaccines", adding that the "extraordinary circumstances of the Covid-19 pandemic call for extraordinary measures".
The comments come as the United States and Britain see a highly successful rollout of the life-saving jabs, with around about half their populations receiving at least one, while European countries are now seeing a pick-up.
World Health Organization head Tedros Adhanom Ghebreyesus called the announcement "historic" and said it marked "a monumental moment" the battle against the disease, while the European Union said it was ready to discuss the proposal.
It also provided support to broader stock markets, fuelling hopes that the waiver could speed up vaccine programmes around the world and get economies open quicker.
But pharma firms in Asia took a hit, with Shanghai Fosun Pharmaceutical, which has rights to develop and market BioNTech's shot in China, collapsed a record 14 percent in Hong Kong and 10 percent in Shanghai.
CanSino Biologics, which makes one of China's domestic vaccines, dropped 15 percent in Hong Kong and 14.4 percent on the mainland.
Tokyo-listed JCR Pharmaceutical sank 1.4 percent and Pfizer shed more than three percent in India.
The move "probably isn't great news for the vaccine manufacturers who will now face generic copies of their vaccine", said Olivier d’Assier, head of APAC applied research at Qontigo GmbH, said.
But he added "the mutation of the virus has shown continued research and innovation will be needed and that should provide those companies with future earnings from newer vaccines so I would expect the impact to be short-lived and possibly limited".
-- Bloomberg news contributed to this story --