The author is a scientific commentator
The Covid-19 outbreak officially turns three years old on January 30, marking the time in 2020 when the World Health Organization declared the respiratory disease a public health emergency of international concern. But this month’s anniversary offers little to celebrate following China’s chaotic and abrupt transition from zero-Covid to full-Covid.
Beijing has drastically reduced testing, tracing of unwanted contacts and removed most quarantine requirements; Some regions are now allowing infected people with mild or no symptoms to go to work. The pandemic virus is thus free to circulate unobserved in one-sixth of the world’s population – just as the rest of the globe clamors for normalcy. As the outbreak’s third year draws to a close amid reports of overwhelmed hospitals in China and new restrictions on air travellers, and with the Chinese New Year holiday fast approaching, the pandemic appears to be in somehow more familiar and less predictable than ever.
China is right to abandon its inhumane and unworkable zero Covid policy, but it has done so from a position of relative weakness. An overall vaccination rate of 90% masks the reality that its local vaccines are less effective than mRNA vaccines widely used elsewhere, and that about 30% of the country’s 260 million over-60s (and more than half of her over 80s) have not received a third dose. These factors have led to terrifying projections, ranging from 1 million deaths this year to 1.7 million deaths by the end of April – and prompted the EU to offer free vaccines to China.
Tellingly, China recently changed the way it counts its Covid deaths, only including in its count those who expire directly from respiratory failure and pneumonia. The official national Covid death toll in December appeared to stand at 14. While Chinese authorities privately estimated nearly 37 million new infections on December 20, no new cases have been reported since December 23. The situation looks surreal different from last year, which saw serious discussion about whether the WHO should declare an end to the Covid emergency.
Leaving aside the domestic tragedy, a question for the rest of the world in 2023 is whether uncontrolled transmission in China will result in a new variant capable of circumventing the immunity conferred by existing vaccines. Some variants can lead to new waves of infection, as happened in late 2021 when Delta was usurped by Omicron. This created Omicron surges around the world in 2022 and accelerated vaccine reformulation.
The data indicates that the two most common strains currently circulating in China are Omicron subvariants descended from BA5, the strain that plagued the United States and Europe last year. Scientists, particularly those on the WHO’s technical advisory group on the evolution of Sars-Cov-2 which was due to meet yesterday, are now on the hunt for “pi”, the potential successor to Omicron.
What matters is whether new viral incarnations are able to spread more easily or make people sicker (or both), deserving of designation as a “variant of concern.” Professor Eddie Holmes, the University of Sydney evolutionary biologist who helped colleagues in China share the genome of the original Wuhan strain in early 2020, speculated that the low transmission of Covid to date in China offered less pressure for the virus to evolve, limiting the chances of a dangerous variant emerging in the region.
“My view is that Sars-Cov-2 in China has an open target in front of it: a population with very low levels of permanent immunity,” he told me in an email, suggesting that the dominant variants in the country would most likely .]be those that gained a foothold early in the epidemic. “It is not obvious to me that there will be strong immune selection for antigenically distinct variants because so few of the population [in China] has prior immunity. Populations with greater but declining immunity, Holmes wrote, were more likely to be sources of new variants, adding “it is noteworthy that XBB 1.5 was first detected in the United States.”
XBB 1.5, a subvariant of Omicron, is rapidly becoming the dominant strain in the United States, now accounting for about four in 10 cases according to the US Centers for Disease Control and Prevention. The good news, at least for now, is that XBB 1.5 is not causing increased hospitalizations and deaths, despite being dubbed the Kraken.
In other words, vaccines always work. It’s worth toasting, although with a precarious situation in China and a new variant in the mix, one cannot be sure that the third anniversary of the pandemic will be the last.
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