Why China could face a Covid-19 catastrophe

China is the only major nation that until now has continued to enforce a zero-Covid strategy. Other countries, including Australia, New Zealand and Singapore, also sought to eliminate the virus entirely earlier in the pandemic.

But all eventually abandoned this approach because of the mounting social and economic costs and the realization that elimination of Covid-19 was largely futile and only transient.

China’s strategy has relied on measures including mass testing and shutdowns of entire cities and provinces. It has also involved quarantining anyone who may have been exposed to the virus. Yet this has become untenable.

The harsh and often arbitrary enforcement of zero-Covid has fuelled growing resentment among the population, culminating in large public protests.

The restrictions have also shown their limits in the face of Omicron. This variant has a shorter incubation period than previous Covid lineages, and largely bypasses protection against infection conferred by the original vaccines.

Tiny fraction

It’s logical that Chinese authorities are now moving to ease restrictions. However, the transition out of zero-Covid has been painful for any country that’s done it. And the ruling Communist Party faces some unique challenges in making this shift.

China has successfully suppressed widespread Covid transmission since early 2020. Although figures differ between sources, close to 10 million cases have been reported to the World Health Organization since January 2020.

This represents only a tiny fraction of the nation’s population, numbering 1.4 billion. So, the population has acquired minimal immunity to the virus through exposure.

Vaccination rates in the country are largely in line with those in Western nations. But an unusual feature of China’s program is that they decrease with age.

Tracking Covid’s death rate

Older adults are by far the demographic at the highest risk of severe symptoms if they contract Covid. Yet only 40% of people over 80 have received three doses.

Vaccine efficacy against transmission has been severely tested, especially since Omicron started spreading in late 2021. That said, protection against severe disease and death provided by the mRNA vaccines used in Western countries has remained high.

China has used different vaccines – primarily “inactivated” shots made by Sinovac and Sinopharm. Inactivated vaccines are based on pathogens or the SARS-CoV-2 virus that causes Covid-19. But these are killed or inactivated before inoculation.

Inactivated vaccines are generally safe, but they tend to elicit lower immune responses than mRNA vaccines such as Pfizer and Moderna or adenovirus vector-based vaccines like AstraZeneca and Johnson & Johnson.

The performance of the Chinese vaccines has been mixed. While two doses of the Sinovac shot reduced deaths by 86% in Chile, results from Singapore suggested the inactivated vaccines provided poorer protection against severe disease relative to their mRNA counterparts.

Delta strain

It’s true the globally dominant Omicron variant is associated with significantly lower disease severity and death than the Delta strain it replaced. But Omicron remains a major threat for populations with little prior immunity – particularly among the elderly.

Hong Kong was facing similar problems to mainland China in early 2022 with comparably low virus exposure across the population. Hong Kong had even poorer vaccination rates among older adults than the mainland does now, though a more robust healthcare system.

The Omicron wave that swept Hong Kong in March 2022 led to more deaths per inhabitant in a matter of days than many countries have seen through the entire pandemic.

Also, Covid infections are now rising quickly in China, numbering above 27,000 new daily cases in recent days. As various restrictions are eased, there’s little question the figures will continue to soar.

Given the low level of immunity in the country, a major surge would likely see large numbers of hospitalizations and might lead to a dramatic death toll.

If we assume, 70% of the Chinese population becomes infected in the months ahead, then if 0.1% of them die – a conservative estimate of Omicron’s mortality rate in a population with hardly any exposure – calculations suggest around one million deaths.

There is relatively little China can do at this stage to avert significant death and disease – though, any last-ditch vaccination campaign focusing on older adults will likely help.

Chinese healthcare is fragile and the dearth of critical care beds represents a particular vulnerability. The country would be well-served to lift restrictions gradually, to try to “flatten the curve” and avoid the healthcare system becoming overwhelmed.

Effective triaging of patients, in particular ensuring that only those most in need of care are admitted to hospital, could help reduce deaths if the epidemic got out of control.

A major wave in China will not necessarily have a significant impact on the global Covid situation. The SARS-CoV-2 lineages spreading in China, such as BF.7, can be found elsewhere around the world.

Humanitarian catastrophe

Circulation in a largely immunologically naive population should not exert much additional pressure on the virus to evolve new variants that can escape our immunity. But Beijing is facing a possible humanitarian catastrophe, and I would argue this is a much greater challenge.

There’s an irony in China being the first country affected by Covid and also the last to give up on its elimination.

Chinese authorities pioneered and championed unprecedented measures to suppress viral spread, providing a blueprint for harsh pandemic suppression strategies globally. China then implemented those measures more ruthlessly and for longer than any other major country.

Yet in the end, zero-Covid proved largely futile. China, the last domino, will fall soon due to the unsustainable social and economic costs of the policies. The virus will spread as it did elsewhere, leaving in its wake death and bitter dissension in the population.

Francois Balloux is the Chair Professor of Computational Biology at the University College London or UCL.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The views and opinions expressed in this article are those of the author and do not necessarily reflect the official policy of China Factor.