The efficiency of “Zero-COVID” strategies

The story so far: On January 15, China’s capital, Beijing, reported its first case of the Omicron variant, two weeks ahead of its hosting of the Winter Olympics. This followed cases in Tianjin as well as an outbreak of the Delta variant in December in Xian, which reported the most cases of any city in China since the pandemic began in Wuhan in early 2020. The recent cases have sparked a debate on whether China’s “Zero-COVID” strategy and stringent lockdowns are sustainable two years into the pandemic.

How does a “Zero COVID” strategy work?

The Zero-COVID strategy is predicated on a series of measures, includingcontinuingstringent restrictions on international travel, mass testing, contact tracing every case, targeted lockdowns, and quarantining of close contacts usually in central facilities until an outbreak is completely controlled and cases are brought to zero. After Australia, Singapore and New Zealand last year loosened restrictions and opened up to the world, the Zero-COVID approach is currently only being followed on the Chinese mainland, Hong Kong and Taiwan.

In all three regions, the Zero-COVID approach over the past two years has limited the number of total cases and enabled all three to avoid a major second wave, as was seen around the world. The strategy has, however, meant continued isolation from the rest of the world with restrictions on international travel as well requiring foreign arrivals to undergo mandatory quarantine in Government-designated facilities.

Has Omicron changed the calculus?

If this approach helped limit the Delta outbreaks, the more transmissible Omicron variant, experts say, has challenged the Zero-COVID playbook. In January, both Tianjin and Hong Kong reported Omicron cases in which the chain of transmission could not be determined. In December, Xian in northwestern Shaanxi province reported the biggest spread of any city in China since Wuhan in early 2020, with more than 2,000 cases, although authorities attributed the Xian cluster to the Delta variant.

The Xian lockdown, starting in December 23, appeared to work in bringing cases down to only a dozen after the second week of January. However, the stringency of the measures ignited a debate in China whether, two years into the pandemic, such an approach could still be justified. The case of a pregnant woman who was turned away from a hospital because of the lockdown and then suffered a miscarriage caused widespread outrage and raised questions whether such an approach was sustainable in the long-term given the costs borne by residents, from being denied access to healthcare for other ailments, as well as the economic costs incurred by repeated lockdowns.

What about vaccination rates?

If lockdowns were understandable in 2020 before vaccines were widely available, public health experts have questioned the rationale of this approach when large segments of the population are vaccinated. In China, 85% of the population has been fully vaccinated while close to 25% have been given a booster. While Chinese vaccines have been shown to be less effective than mRNA vaccines in preventing infection, they have been shown to be effective in preventing hospitalisation and serious cases.

Amid the debate about the Xian lockdown, leading Chinese expert Wang Guangfa of the Peking University First Hospital in Beijing told official media that while China was approaching herd immunity through vaccination “the high percentage of vaccination doesn’t mean the country should let its guard down, as purely relying on vaccination has demonstrably failed to control the epidemic”. He cited the examples of Israel and the U.K.

Is “Zero COVID” likely to continue in 2022?

Health authorities in China have said they fear hospitals would be overrun if Omicron was left unchecked. One reason for that is since the start of the pandemic, the messaging to the public has been consistent that all positive cases need to seek treatment and cannot simply isolate at home. Large numbers would hence overwhelm health infrastructure until that messaging changes. Some health experts have said opening up will not happen until there is wider booster coverage, because of concerns about waning effectiveness of vaccines, and greater availability of antivirals.

There is also a political argument as far as China is concerned. For months, the Communist Party has hailed the success of its Zero-COVID playbook as a counterpoint to soaring cases in the U.S. The Government also has one eye on the Winter Olympics in February, and the other on the once-in-five-year Party Congress in October that will see the start of President Xi Jinping’s third term.

So, until cases worldwide subside, booster coverage expands and antivirals are easily available, the restrictions are likely to continue regardless of the economic costs of continued lockdowns and international isolation. This means the approach is likely here to stay for the coming year.