China reports first imported cases of 'more contagious' Omicron Subvariant BA.2.12.1 and BA.4

(ECNS) -- China has reported the first imported COVID-19 infections caused by the “more contagious” Omicron subvariant BA.2.12.1 and BA.4 respectively, according to epidemiological surveys by the Chinese Center for Disease Control and Prevention.

The case of Omicron BA.2.12.1 was a 27-year-old Chinese man who had been vaccinated. The man arrived at Guangzhou Baiyun International Airport, Guangzhou City, South China’s Guangdong Province on April 23, on flight KQ880 from Kenya’s capital Nairobi, according to a report published on May 16 by Chinese Center for Disease Control and Prevention (China CDC).

The first case of Omicron BA.4 infection was a 20-year-old woman who also arrived at Guangzhou Baiyun International Airport from Amsterdam Schiphol Airport, Netherlands and was admitted to an isolation hotel on April 29. The next day, she tested positive for novel coronavirus.

The World Health Organization reminded people to closely monitor the two subvariants. Compared to other Omicron variants, both BA.2.12.1 and AB.4 subvariants show stronger immune escape, even after having been vaccinated with booster dose. Several studies have shown that the transmissibility of BA.2.12.1 is about 23 to 27 percent faster than that of BA.2.

Cases infected by BA.2.12.1 subvariant have been reported in at least 17 countries.

BA.4 is driving the upsurge in South Africa and has rapidly replaced BA.2, with over 50 percent of sequenced cases since the first week of April 2022. Cases of BA.4 infection have been reported in at least 20 countries, mainly from South Africa (62.39 percent).