Shanghai Fosun Pharmaceutical Group Co., which has the rights to develop and market BioNTech SE’s shot in China, advanced as much as 7% in Hong Kong after sinking 14% the previous day. Walvax Biotechnology Co. gained 3.7% in Shanghai, one of the best performers in the benchmark CSI 300 Index.

In the U.S., Pfizer Inc., BioNTech SE, Novavax Inc. and CureVac NV all pared an earlier slump.

Some analysts had urged for caution to the news prior to Merkel’s announcement. The Biden administration’s plans will only open up a negotiation at the WTO and other countries and members remain unwilling, said Barclays analyst Carter Gould in a note.

For Evercore ISI analyst Umer Raffat, U.S. support didn’t mean it was a “100% done deal” as other countries are also opposed. It “remains to be seen if U.S. leadership’s position sways others,” Raffat wrote in a note.

With many countries struggling with a resurgence of the virus, U.S. Trade Representative Katherine Tai said Wednesday the Biden administration will take part in negotiations for the text of a waiver of the rights at the World Trade Organization. The European Union said Thursday it was willing to participate.

Big Business

Vaccines have been a big business for the firms that make them, with Pfizer, BioNTech’s partner outside of China, raising its forecast for 2021 vaccine sales to $26 billion just this week.

Read more: Analysts say investor fears of U.S. vaccine waiver support are overblown

The International Federation of Pharmaceutical Manufacturers & Associations condemned the move as “disappointing.”

“A waiver is the simple but the wrong answer to what is a complex problem,” the group said in a statement. “Waiving patents of Covid-19 vaccines will not increase production nor provide practical solutions needed to battle this global health crisis.”