First infection of Omicron BA.5 reported in the Chinese mainland
Published: May 29, 2022 10:25 PM

Photo: CFP
Photo: CFP

The Chinese mainland has reported its first infection of COVID-19 caused by the Omicron BA.5 subvariant, according to a weekly report from the Chinese Center for Disease Control and Prevention (CDC). The patient, who received four doses of COVID-19 vaccine, was diagnosed with the virus after arriving in Shanghai from Uganda in late April.

The patient departed Uganda on April 25 with stopovers in the Netherlands, on April 26, and in South Korea, on April 27, before arriving in Shanghai. The patient recovered and was discharged from the hospital on May 12, according to a report released on Saturday in the CDC Weekly Report.

The Omicron subvariant BA.5, first found in South Africa in February, has increased its prevalence in the country in recent weeks and spread to 19 other countries over a three-month period. The BA.5 subvariant has led to an increase in the number of cases in countries such as Portugal while South Africa has reported a modest increase in hospitalizations since the end of April.

"BA.4 and BA.5 have three amino acid mutations in their echinoderm proteins, compared to BA.2. So, the WHO also said it will keep monitoring them," Jin Dongyan, a virologist and professor of the School of Biomedical Sciences at the University of Hong Kong, told the Global Times.

The first cases caused by Omicron subvariants BA.4, BA.2.3 and BA.2.12.1 have also recently been identified in the Chinese mainland.

"If the virus remains prevalent and shows the current transmission characteristics, it is quite normal that its nearly 30,000 nucleotides will have one or two mutations per month, while the mutant strain will not change too much," Jin told the Global Times. "In fact, the rate of COVID-19 mutations is at a low level compared to other viruses."

As long as the mutated strains do not undergo major changes, the public need not worry too much, Jin said.

"The biggest effect of these small drifting mutations, in general, is helping the epidemiological investigators and disease control specialists do their jobs better. They are not likely to make impact on vaccine effectiveness or anti-epidemic policies," Jin remarked.