No new variants of the coronavirus have been identified, says WHO after meeting with China

The World Health Organization (WHO) and China held a meeting on December 30 on the rise of Covid-19 cases in the country.

To seek more information on the situation, experts from China’s National Health Commission and the National Administration for Disease Control and Prevention attended the meeting.

This Wednesday (4), the WHO released a statement stating that no new coronavirus variant or mutation of known significance was observed in genetic sequencing data made available by the Asian country.

A new variant represents concern in the face of the possibility of impacts on vaccines in use and on diagnostic tests, increased transmissibility of the virus and the severity of the disease.

The Technical Advisory Group on Virus Evolution (TAG-VE) meets regularly to review the latest scientific evidence on circulating SARS-CoV-2 variants and advise WHO on the need for a shift in public health strategies. TAG-VE met on Tuesday (3) to discuss the disease situation in China.

Scientists at China’s CDC presented genomic data from what they described as imported and locally acquired cases of coronavirus infections. For locally acquired infections, the data presented were based on more than 2000 genomes collected and sequenced as of December 1, 2022.

China CDC analysis showed a predominance of Omicron strains BA.5.2 and BF.7 among locally acquired infections. Together, the two strains accounted for 97.5% of all local infections according to genomic sequencing.

Some other known Omicron sublines were also detected, although in low percentages, according to the WHO. These variants are known and circulating in other countries, and at this time, no new variants have been reported by the China CDC.

As of 3 January, 773 sequences from mainland China have been submitted to the Gisaid international database, with the majority (564 sequences) collected after 1 December 2022. Of these, only 95 are labeled as locally acquired cases, 187 as imported cases, and 261 does not have this information provided.

Of the locally acquired cases, 95% belong to BA.5.2 or BF.7 lineages. According to the WHO, the findings are in line with the genomes of travelers from China sent to the Gisaid database by other countries. No new variants or mutations of known significance were observed in the publicly available sequence data.

Transparency and data sharing

The WHO advisory group reiterated the critical need and importance of further analysis and sharing of sequencing data to understand the evolution of SARS-CoV-2 and the emergence of mutations or variants of concern.

The experts stressed that it is essential for global risk assessment to maintain high levels of representative genomic surveillance in China and globally, annotate genomic sequences with relevant clinical and epidemiological metadata, and quickly share this data with the scientific community.

WHO further stated that at this time, the VE-TAG also assesses the increasing proportion of XBB.1.5 in the United States and other countries. An updated risk assessment of XBB.1.5, in addition to the previous statement, is in progress.