Almost 90% of the coronavirus cases found in Thailand are of the Alpha coronavirus variant first found in the United Kingdom, according to the Department of Medical Sciences.
Studies of 4,185 cases in Thailand conducted in collaboration with university laboratories from April-June found that the Alpha variant had infected by far the most people, 3,703 or 88.48%, said DMS director-general Supakit Sirilak.
Just 348 cases, or 8.32%, were found to be of the Delta variant first detected in India and 98 cases, or 2.34%, were B.1 (dade G), B.1 (dade GH), B.1.1.1 (dade GR), first found in China, he said.
Also, 26 cases, or 0.62%, were of the Beta variant, first found in Africa, and the rest, 10 cases or 0.24%, were of the B.1.524 variant.
Dr Supakit cited studies by Public Health England (PHE) and the World Health Organization (WHO), confirming the Alpha variant to be more contagious and more deadly compared with the original strain.
However, vaccinations could still be effective against it," said Dr Supakit.
The Delta (Indian) variant was more contagious than Alpha, he added, but infections were less severe and vaccinations were effective in preventing it
Meanwhile, the Beta variant spread slower but it has caused more death than the original variant, he said.
As of Wednesday, 348 Delta patients had been detected across the country: 318 in Bangkok, 17 in Udon Thani, two each in Saraburi, Nonthaburi, Khon Kaen and Chaiyaphum, and one each in Phitsanulok, Roi Et, Ubon Ratchathani, Buri Ram and Samut Sakhon.
Dr Supakit said the reports would help people to be aware of these variants and their different effects so that they could regularly take care of themselves.
Meanwhile, Thira Woratanarat, an associate professor at Chulalongkorn University's Faculty of Medicine, on Thursday cited UK studies and stressed the importance of having two doses of the Covid-19 vaccine.
He noted on Facebook that the time interval between the first and second jab must not be too long.
According to the studies in the UK, Dr Thira wrote, infection from the Delta variant could be prevented by one dose of the Pfizer or AstraZeneca vaccines, but only slightly, so two doses were recommended.
According to PHE, a study conducted from April to May 16 found that "the Pfizer-BioNTech vaccine was 88% effective against symptomatic disease from the [Delta] variant two weeks after the second dose, compared to 93% effectiveness against the [Alpha] variant".
"Two doses of the AstraZeneca vaccine were 60% effective against symptomatic disease from the [Delta] variant compared to 66% effectiveness against the [Alpha] variant," PHE said.
It noted that three weeks after the first dose each vaccines was only 33% effective against symptomatic illness from the Delta variant, compared to about 50% effectiveness against the Alpha variant.
UK Health Minister Matt Hancock said this week the Delta variant was estimated to be 40% more transmissible than the Alpha variant.
