China's level of COVID immunity is not strong enough to fight an uncontrolled omicron epidemic, which could cause a "tsunami" of 1.55 million deaths if allowed to spread unchecked. That's according to a peer-reviewed report from Shanghai's Fudan University that published in the journal Nature on Tuesday. It comes as China faces criticism and anger from some locked-down citizens over the country's "Zero COVID" approach to virus control. "We find that the level of immunity induced by the March 2022 vaccination campaign would be insufficient to prevent an Omicron wave that would result in exceeding critical care capacity with a projected intensive care unit peak demand of 15.6-times the existing capacity and causing approximately 1.55 million deaths," the study's authors said. The country has seen progress in controlling the virus in major cities such as Shanghai, under lockdown in some places for a month. But officials there have warned relaxing measures too early would see the virus rebound. The head of the World Health Organization Tedros Adhanom Ghebreyesus this week criticized the country's strict policy as not sustainable.