Samples collected from patients in the new wave of Covid-19 infections showed that many were infected by the British strain of the virus, which spreads 1.7 times faster and generates a far higher viral load in patients.
The most recent wave was sparked by clusters in several nightspots in Bangkok and its vicinity.
Judging by the fact that the UK strain has infected more than 1,500 people in Cambodia since February 20, expert virologist Dr Yong Poovorawan believes it may have been brought into Thailand by people crossing the border.
Dr Anan Jongkaewwattana, a virologist with the National Centre for Genetic Engineering and Biotechnology (BIOTEC), said the AstraZeneca vaccine appeared to be the most effective against the mutated strain compared to the Chinese Sinovac vaccine.
Only 0.5 per cent of Thai population vaccinated
As of press time on Thursday, more than 711 million doses of the vaccine had been administered globally, with Israel leading the list with more than 60 per cent of its population inoculated with either the Pfizer or Moderna vaccine.
The second highest is the United Kingdom, where 46.7 per cent of the population has been inoculated. In Thailand, just 336,808 people or 0.5 per cent of the population, have received a jab.
Effectiveness of vaccines registered in Thailand
As of Thursday, the Public Health Ministry had approved three vaccines – AstraZeneca, Sinovac and Johnson & Johnson – for use in Thailand.
However, the manufacturers and researchers say that each vaccine’s effectiveness towards different strains varies.
AstraZeneca is 70 to 79 per cent effective against the normal strain, and 70 to 80 per cent effective against the UK strain.
Sinovac provides 50 to 91 per cent protection against the normal strain, but its effectiveness against the British strain has yet to be determined.
Meanwhile, the Johnson & Johnson vaccine provides 66 to 72 per cent protection against the normal strain and 70 per cent against the British strain.