However, study shows no presence of the UK, South Africa, or Brazil variants of Covid-19
Bhutan as of today has not recorded the presence of the three highly contagious variants of the SARS-CoV-2 virus, which causes Covid-19.
According to scientists, the three variants, which are of public health concern for now are the UK (B.1.1.7), South African (B.1.351), and the Brazilian (B.P) variants of SARS-CoV-2 virus.
However, health officials said that there are over 200 variants of the virus circulating today since the virus’s genome was first sequenced in China last year.
Bhutan too recorded some seven different variants of the virus during the recent two outbreaks.
Royal Centre for Disease Control’s (RCDC) head, Dr Sonam Wangchuk, said that following the first outbreak of Covid-19 in August last year, samples were sent to the World Health Organisation’s reference laboratory in Thailand for gene sequencing.
He said that four variants of the virus were identified from 25 samples collected from the Phuentsholing outbreak and from those returning from abroad. The predominant variant then was the B.1.36 variant (64 percent), followed by B.1.36.1 variant (16 percent), B.1.1 variant (12 percent) and B.1 variant (8 percent).
“At this point in time, the UK variant did not exist. We just wanted to know what type of variants were circulating then.”
He said that the B.1.36 variant of the virus was predominately circulating in India during the same period. “Epidemiologically, we knew the source of the Phuentsholing outbreak was from across the border. It was also genomically established that the source of the outbreak was from across the border through the gene sequencing test.”
RCDC sent another group of samples from the recent outbreak in December to the WHO lab in Thailand. The preliminary results identified three variants — B.1 (56.5 percent), B.1.124 (39 percent) and B.1.1.67 (4 percent). These variants were also predominantly circulating in India at around the same time.
Dr Sonam Wangchuk said that given the rate at which the December outbreak spread, they suspected the highly transmissible UK variant behind the outbreak. “However, it wasn’t the case. As of now, we have not recorded any of the three variants which are of public health concern.”
Why are different variants of concern?
While the idea of a virus mutating might sound scary, it is actually quite normal according to experts. Viruses mutate constantly, especially with those containing RNA as their genetic material, such as coronaviruses and influenza viruses.
Dr Sonam Wangchuk said that the three variants of SARS-CoV-2 virus which are of public health concern are accordingly deemed so for their impact on the efficacy of the vaccine, therapeutic management, and diagnosis.
He explained that the current vaccines, therapeutic management, and diagnostic (testing) are based on the genome of the virus sequenced at the beginning of the pandemic. “As the virus mutates and new variants are identified, vaccine development or diagnostic tests also have to be accordingly updated.”
He said that studies have already shown the AstraZeneca vaccine being ineffective against the South African variant (B.1.351) as the mutation is at some of the critical structure of the virus, which is of concern.
However, he added that the AstraZeneca vaccine, which Bhutan plans to roll out, was still effective against the UK variant. “But we still need more information on how these variants may affect the existing therapies, vaccines, and tests. Many things are still unknown for now, and researches are underway.”
Dr Sonam Wangchuk said that as the virus was likely to change continuously, it was important to build the country’s capacity to conduct its own gene sequencing. For this, he said that the RCDC had already received gene sequencing machines from the WHO in 2019.
However, it was not specifically procured for Covid-19 then. Experts from India were brought in to install the machine and set up a laboratory at RCDC.
“Before we could complete the setup, the pandemic hit us and the experts could not come to install and validate the machine,” said Dr Sonam Wangchuk. “Officials from the manufacturing firm are expected to arrive soon.”
However, training the RCDC staff to analyse the data from the machine is expected to take longer. “While we build our capacity, we can send the data for analysis to the WHO reference lab.”
He added; “Although the virus is not circulating in our community, for now, it is important to know what type of variants are coming through people coming in from abroad.”