Models predict massive wave of illness and death if China lifts ‘zero COVID’ policy

Surprised and stung by protests against draconian “zero-COVID” policies, Chinese authorities are moving cautiously to ease the burden of constant lockdowns, quarantines and testing. But 3 years into the pandemic, China shows no signs of planning a major course change. Mathematical models suggest why: the country is still ill-prepared to live with SARS-CoV-2. Easing restrictions today would likely trigger a massive wave of infections, overwhelm healthcare facilities and lead to a high death toll.

“China hasn’t achieved high vaccination rates, hasn’t used the best kind of vaccines, and has been very slow to communicate [to the public] the eventual need to move from elimination to suppression and mitigation,” says public health scientist Nick Wilson from the University of Otago, Wellington, New Zealand. Other countries that initially followed the zero COVID strategy, including New Zealand, used it to buy time to increase vaccination rates, stockpile antivirals and increase critical care capacity.

The fierce protests triggered some changes. Several provinces have started allowing people to enter public transit, restaurants and malls without proof of a negative COVID-19 test, for example, and some close contacts of patients will be allowed to self-isolate at home. instead of being sent to quarantine centers. . These measures are “a small but important step, and I think more steps will follow,” said a Chinese scientist who asked to remain anonymous. “It will alleviate some of the pandemic fatigue and reduce the burden on the economy and society.”

But the models show why the Chinese government still wants to stay the course. A study based on vaccination rates in March, published in natural medicine in May, found that lifting zero-COVID restrictions at this point could “generate a tsunami of
cases of COVID-19” over a 6-month period, with 112 million symptomatic cases, 2.7 million intensive care unit (ICU) admissions and 1.6 million deaths. The peak demand for intensive care beds would reach 1 million, more than 15 times the current capacity.

The unvaccinated would represent 77% of deaths, according to the authors, mainly at Fudan University. Rising vaccination rates could reduce the toll, but China’s elderly population remains wary of vaccination. Even today, only 66% of people aged 80 and over have received two doses, compared to 90% of the general population, and only 40% have taken boosters.

Hong Kong provides a cautionary tale: a large outbreak of Omicron earlier this year caused almost 6,000 deaths, 96% of them in people aged 60 or over. At the time, Hong Kong’s vaccination rates were even lower than those on the mainland. In the first 3 months of this year, the city recorded a COVID-19 death rate of 37.7 per million population, one of the highest in the world.

A new study published Nov. 28 by Airfinity, a London-based health analytics firm, suggests mainland China remains vulnerable. Lifting zero COVID now could cause between 167 million and 279 million cases and between 1.3 million and 2.1 million deaths over 83 days, according to the report.

In addition to being underutilized, China’s vaccines – which contain inactivated virus – are less effective than messenger RNA (mRNA) vaccines available elsewhere. A study in Hong Kong, where people could choose between the Pfizer-BioNTech mRNA vaccine or CoronaVac, a Chinese vaccine, showed that three injections of either were more than 90% effective in preventing disease. serious and death in people over 60. But two doses of the mRNA vaccine were significantly more effective than two injections of CoronaVac. A separate study suggested that CoronaVac’s protection wanes faster.

In May 2021, BioNTech and China’s Shanghai Fosun Pharmaceutical agreed to form a 50-50 joint venture to manufacture and sell BioNTech’s vaccine in China. But the product never received regulatory approval, possibly to protect Chinese vaccines. Four Chinese companies have mRNA vaccines in various stages of development, but none have been given the green light either. Pfizer’s COVID-19 drug Paxlovid is available in China, as is a locally produced monoclonal antibody therapy, but it’s unclear how many doses the country has.

Mainland authorities are still hoping to increase vaccination rates among the elderly. A November 29 directive from the National Health Commission urged local authorities to set up teams to go door-to-door and assess whether the sick and infirm can be safely vaccinated, and to launch education campaigns to counter vaccine hesitancy.

But those efforts will take time, says Xi Chen, a public health scientist at the Yale School of Public Health. “Reopening too soon will drain resources, overwhelm the medical system and cause more deaths,” he says. For now, China remains trapped in the Catch-22 of its own manufacture.