China CDC Contends Omicron BA.5.2 and BF.7 are Main SARS-CoV2 Variants Circulating – But WHO Pressures for More Genome Sharing
Omicron
A COVID-19 sanitation worker at a ferry in the Chinese port city of Dalian. Relaxation of strict COVID measures and low vaccine rates have led to a surge in cases.

As nations clamp down on travellers from China during an Omicron surge there Chinese health experts have told the World Health Organization that two known Omicron lineages are dominating the current Chinese surge, with BA.5.2 and BF.7 together accounting for 97.5% of all locally-acquired infections. 

The data was contained in a report by WHO’s Technical Advisory Group on Virus Evolution (TAG-VE) released Wednesday, following a meeting with China CDC officials to discuss the COVID surge being experienced in the country.

The TAG-VE meets regularly to review the latest scientific evidence on circulating SARS-CoV-2 variants, and advises WHO on needed changes in public health strategies.

During the meeting, China CDC scientists presented WHO with new genomic data – which they said demonstrates that BA.5.2 and BF.7 together accounting for 97.5% of all locally-acquired infections.

The data on locally-acquired infections was based on more than 2,000 genomes collected and sequenced since Dec. 1, according to the WHO meeting report.

“A few other known Omicron sublineages were also detected albeit in low percentages,” said WHO in its report on the meeting with China CDC. “These variants are known and have been circulating in other countries, and at the present time no new variant has been reported by the China CDC.”

WHO appeals to China for ‘more rapid, regular, reliable’ data

WHO’s Director General Dr Tedros Adhanom Ghebreyesus calls for more transparency from China on COVID surge at first press briefing of 2023.

In a press conference shortly after the report was released, WHO Director General Dr Tedros Adhanom Ghebreyesus called on China to provide more transparent information on sequenced genomes, as well as information on COVID hospitalizations and deaths, which he and other top WHO officials suggested may have been under-reported.

“We continue to ask China for more rapid, regular reliable data on hospitalizations, as well as more comprehensive, real time viral sequencing,” said Tedros.  “WHO is concerned about the risk to lives in China,” he stressed, but added that such data is also essential for WHO to update its risk assessments related to the COVID surge being seen in China and its impacts elsewhere.

“This data is useful to WHO and the world, and we encourage all countries to share it. The data remains essential for WHO to carry out regular, rapid and robust risk assessments of the current situation and adjust our advice accordingly,” he said.

Concern new variants could emerge

COVID worker in Macau, China during summer lockdown. The lifting of restrictions in the late fall led to a surge of cases, leading to fears of new variants.

Tedros also pushed back at the Chinese criticism of travel restrictions that have been imposed by a string of nations during the current surge.

“With circulation in China so high and comprehensive data not forthcoming … it’s understandable that some countries are taking steps they believe will protect their own citizens,” he said.

Australia, Canada, India, Japan, the United Kingdom and the United States, among others, have re-imposed restrictions on travellers arriving from China, such as requiring a COVID-19 test before boarding a flight.

The Chinese government has sharply criticized the additional testing requirements, and threatened countermeasures against the countries imposing restrictions.

“We do not believe the entry restriction measures some countries have taken against China are science-based. Some of these measures are disproportionate and simply unacceptable,” Foreign Ministry spokesperson Mao Ning told a daily briefing on Tuesday.

“We firmly reject using COVID measures for political purposes and will take corresponding measures in response to varying situations based on the principle of reciprocity,” she said.

Continued evolution of Omicron virus reflects need for more data sharing

In contrast to the some 2000 gene sequences said to have been shared with WHO, China has only submitted complete data on 95 cases of locally- acquired variants to the global, open-access GISAID EpiCoV genome database since 1 December, according to the WHO expert report also published Wednesday.

That is out of a total of 564 sequences submitted since that date. Of those cases, another 187 are considered to have been imported, and 261 cases are unclassified, according to WHO’s report on the meeting.

That being said, China’s claims that the preponderance of BA.5.2 and BF.7 locally acquired infections “is in line with genomes from travellers from China submitted to the GISAID EpiCoV database by other countries,” the WHO report stated.

Both Tedros and the TAG-VE expert group emphasised the critical need for more surveillance and sharing of sequence data not only in China but worldwide, in order to understand the evolution of SARS-CoV-2 and the emergence of concerning mutations or variants.

In particular, WHO is evaluating rapidly increasing cases of the Omicron XBB.1.5 subvariant in the United States, Europe, and elsewhere, and plans to soon release an updated risk-assessment of XBB.1.5 beyond the statement issued in late October.

“Outside of China, one of the Omicron variants originally detected in October 2022 Is XBB.1.5, a combination of two Omicrong BA.2 sublineages,” said Tedros. “It’s on the increase in Europe and the US, and has now been identified in more than 25 countries. WHO is following closely and assessing the risk of the subvariant and will report accordingly.”

Use all available vaccine tools

Kate O’Brien, director of WHO’s Department of Immunization, Vaccines and Biologicals.

At Wednesday’s press briefing, WHO again urged China to make full use of all available COVID-19 vaccines to combat its current Omicron surge – including mRNA vaccines that are more effective than China’s Sinovac and Sinopharm vaccines.

Chinese-made COVID vaccines are based on traditional vaccine technology using inactivated viruses, and that technology has been demonstrated to be less effective than new mRNA vaccines against the SARS-CoV2 virus, explained WHO’s Kate O’Brien at Wednesday’s briefing.

As a result, Chinese citizens need to get three doses of locally produced vaccines to obtain the same level of protection as two mRNA doses, she said.  And current Chinese vaccination rates fall far short of that goal.

Despite the surge of COVID cases in China, and the rapid spread of new subvariants elsewhere, Tedros expressed continued optimism that 2023 could be the year when the COVID pandemic might finally be declared as over.

“COVID-19 will no doubt still be a major topic of discussion, but I believe that with the right efforts this will be the year the public health emergency officially ends.”

Image Credits: Jida Li/Unsplash, Photo by Renato Marques on Unsplash.

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