So far, no novel SARS-CoV-2 variants from Beijing—and hopefully better scientific cooperation going forward

In early December, 2022, China abandoned what until then had been among the most stringent policies against the COVID-19 pandemic globally.¹ Termed the “dynamic zero-COVID policy”, mass testing, strict quarantine protocols, and movement controls had aimed to bring COVID-19 outbreaks under control before they could spread.² This approach proved highly effective: from Jan 22, 2020, until Nov 1, 2022, per million population, China recorded a cumulative 726 COVID-19 cases and 3·9 deaths, compared with 288 384 cases and 3166 deaths in the USA.³ Following the abrupt reversal of this policy, there was a massive surge in SARS-CoV-2 infections in parts of China. Revised reporting criteria (eg, asymptomatic cases are no longer included) conceal its true extent, but reports suggest a substantial number of cases of infection and severe disease and deaths.4, 5

For most of the world, the prevailing strategy of learning to live with COVID-19 is based on widespread immunity, to protect most individuals from developing severe COVID-19 and thus preserve health system capacity. Testing, treatment, and vaccination campaigns, especially with updated (bivalent) vaccines, also have roles to varying degrees. In China, immunity resulting from previous infection was rare due to COVID-19 being effectively suppressed, a substantial proportion of older people were apparently not fully immunised, and the inactivated whole virus COVID-19 vaccines mostly used were not highly effective nor specific for the omicron variant of concern.6, 7

Most concerning for the rest of the world are the potential global consequences of China's abandonment of its zero-COVID policy. Previously, China controlled travel very strictly, with relatively few travellers entering or leaving the country and strict testing and quarantine regimens. The resumption of travel and easing of these restrictions mean that China's COVID-19 trajectory is no longer largely decoupled from the rest of the world.

Although passengers with SARS-CoV-2 infection arriving from China are unlikely to pose public health challenges per se, the persistent paucity of genomic data from China has raised concerns about the introduction of novel SARS-CoV-2 lineages possibly emerging during a massive epidemic wave.⁸ Less than 0·1% of positive cases in China have had SARS-CoV-2 genome sequences submitted to GISAID, a platform for sharing of viral genomic data; this contrasts with 12% for the UK and 1·2% for South Africa. Consequently, several countries introduced screening measures, including SARS-CoV-2 genome sequencing of samples from individual infected passengers or aircraft or airport wastewater.⁹ Early reports indicate sometimes substantial numbers of infected travellers, but viruses found so far represent viral lineages already circulating widely outside China.¹⁰ Similarly reassuring genomic data have been presented to WHO.¹¹

In The Lancet, Yang Pan and colleagues¹² report on and analyse the currently unfolding genomic landscape of SARS-CoV-2 variants in Beijing. Before December, 2022, Beijing had seen numerous importations and one larger outbreak earlier in 2022, but no ongoing local transmission of SARS-CoV-2. For a 5-week period commencing in mid-November, 2022, 350 locally acquired infections and 63 imported cases were sequenced. Omicron descendent lineages BA.5.2 and BF.7 dominated (90%), and all remaining viral genomes belonged to known Pango lineages. It is certainly reassuring that this study yielded no evidence for novel SARS-CoV-2 variants, but not a surprise: the surge is amply explained by the abrupt cessation of effective control measures.

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The study is subject to several limitations. It covers a short period within a few weeks of the lifting of the zero-COVID measures. If new lineages were to emerge in the course of the surge, the study was probably too early to find them. One can also only sequence samples that tested positive; with the previously massive testing efforts in China now stopped, only a small fraction of infected individuals are tested. Insufficient COVID-19 testing is seen in many other countries, too. Furthermore, the situation in Beijing may not be representative of the whole of China. In the USA, for example, the XBB.1.5 subvariant continues to be restricted largely to the northeastern parts of the country so far, despite being highly transmissible.¹³ The SARS-CoV-2 molecular epidemiological profile in one region of a vast and densely populated country cannot be extrapolated to the entire country. In other regions of China, other evolutionary dynamics might unfold, possibly including animal species that could become infected by human beings and spill back a further evolved virus.

It is welcome to see these much-needed data from China. Although the fairly mild travel-related measures imposed by some countries for travellers from China once again might be viewed as punitive, one can but hope that this paper heralds more openness and prompt exchange of data going forward. The mutual criticisms and even accusations over the past 3 years have caused substantial sensitivities between China and other countries. Nevertheless, the world sorely needs timely genomic and other data (eg, reliable figures for cases and deaths) from all regions of China, as from anywhere else. A prompt and unimpeded flow of vital data is key to countering the ongoing COVID-19 pandemic and many other health threats.14, 15