Rising number of Omicron BA.4, BA.5 cases in Europe, South Africa
Global science initiative GISAID has reported that Europe and South Africa have found more patients infected with Omicron, specifically the BA.4 and BA.5 subvariants, which have mutated from the original Covid virus found in Wuhan, Dr Wasan Chantrathit, chief of Ramathibodi Hospital’s Centre for Medical Genomics, said on Wednesday.
“It is worrying that tests show BA.4 and BA.5 can multiply quickly in human lung cells, which could cause pneumonia easier than the BA.1 and BA.2 subvariants, which can multiply faster in the upper respiratory mucosa but rarely spread down to the lungs,” he said.
“However, the World Health Organisation [WHO] has yet to announce the BA.4 and BA.5 as subvariants of concern, as further evaluation is yet to be carried out on a large number of hospitalised patients.”
Wasan said that since April 2022, Thailand reported 23 cases of BA.4 and 26 with BA.5, most of whom were foreigners arriving in the country.
Sample testing at residences in Bangkok and the surrounding provinces by the Centre for Medical Genomics found no cases involving the two variants.
According to the GISAID report, infections found in Thailand in the past 60 days can be categorised by subvariants:
• BA.2 – 44%
• BA.2.9 – 26%
• BA.2.10 – 7%
• BA.2.3 – 5%
• BA.2.10.1 – 4%
• BA.2.27 – 3%
• BA.5 – 1%
• BA.4 – 1%
• BA.2.12.1 – 1%.
“It is hard to say if a new surge or outbreak will occur in Thailand, as additional research is required to get to know the new subvariants,” said Wasan.
“WHO has made it clear that Omicron will not be the last Covid variant spreading in the world, therefore we need to continue observing and studying the new mutations, and also make people aware of the current situation so that everyone remains vigilant but does not panic,” he added.