China has reported its first case of the Omicron BA.4 variant. The patient arrived in Guangzhou, South China’s Guangdong Province from the Netherlands on April 29 and was admitted to an isolation hotel. The next day, she tested positive for novel coronavirus. The 20-year-old patient had been fully vaccinated and complied with the 14-day pre-departure requirements prior to the flight.
“There are some studies that suggest BA.4 is about 10 percent more infectious than BA.2, and its R0 may have exceeded 10,” Zhuang Shilihe, a Guangzhou-based immunologist, told the Global Times. “But as most people have received at least two doses of COVID-19 vaccine, more data are needed to assess its exact transmission capacity. There is also no evidence yet of a significant change in its pathogenic capacity.”
On April 27, China reported the first infection caused by Omicron BA.2.12.1. The infected individual arrived in Guangzhou from Kenya on April 23 and was transferred to an isolation hotel. Four days later, he tested positive and was transferred to a hospital for treatment. The infected man had been fully vaccinated.