The new strain of Covid may already be in India: experts
A new variant of the coronavirus that originated in the United Kingdom sometime in September is likely to have already reached India, experts said Tuesday, calling for increased surveillance based on whole genome sequencing to detect the new mutation and prevent further spread.
The new variant, VUI – 202012/01, which accounted for almost 60% of all cases in London in mid-December, is believed to be 70% more transmissible than previous versions of the coronavirus. Scientists are still investigating the effects, virulence, and severity of the new strain.
To prevent the new mutation from taking hold in the country, the government banned flights from the UK from Tuesday evening and administered tests to passengers arriving from Britain. On Tuesday, 22 people, including six from Delhi, tested positive for the virus and their samples were sent for genome sequencing.
“The chance that it didn’t make it to India is low,” said Dr. Anurag Agarwal, director of the Institute for Genomics and Integrative Biology (IGIB), one of the labs that sequence Sars-CoV-2 genomes. He explained that the virus was found to be more transmittable. but he added that transmission could occur only if people did not wear masks.
If precautions aren’t followed, the new variant can lead to over-propagation events, other experts warned.
“The new variant has probably already arrived in India, you will find it only if you are looking for it. This is why we need to increase the amount of genomic sequencing that we are doing. India has the second highest number of Covid-19 cases in the world and it is likely that some variant like this has also been generated within the country, ”said Dr. Shahid Jameel, virologist and director of the Trivedi School of Biosciences of Ashoka University.
He estimated that the country sequences one genome of the virus for every 3,000 positive cases, while the World Health Organization said the ideal would be to sequence one genome out of every 300 positive cases. “And it’s not that we don’t have the capacity. You need to focus more on it, ”he said.
At a government briefing on Tuesday, NITI Aayog member Dr. VK Paul said India will use its laboratory network under the Indian Council for Medical Research, the Department of Biotechnology and the Council for Scientific and Industrial Research. to sequence more samples, especially from travelers. from the UK testing positive.
“Our labs have been asked to prioritize recent virus samples and submit them for genetic sequencing. ICMR, CSIR and DBT labs have been doing it so far, but it will expand. The positive specimen from UK passengers in recent days will also be sequenced, ”he said.
Dr. Agarwal said that some reverse transcription polymerase chain reaction (RT-PCR) kits that use the particular gene where the mutation occurred to detect the virus can give false negatives. “We need to recalibrate our tests. The -PCR generally uses two genes to detect the presence of the virus, we could not insist on a double positive gene to give a positive report, “said Agarwal.
The UK has already issued guidelines for its laboratories to adapt processes to ensure that RT-PCR tests can detect this variant.
One reason for concern was that the mutation was in the spike protein receptor-binding domain, which the virus uses to enter the human body. This protein is also one of the targets of the vaccines that are currently being developed.
But experts said the vaccines would remain effective despite the mutation.
Think of the protein used by a vaccine as a surface; the immune response generated is against the entire surface, so even if there is a change in a particular spot, the vaccine is still effective, ”said Dr. Jameel.
Dr Agarwal added: “The vaccine produces a lot of antibodies and even if some don’t bind, the vaccine is still effective. Other than that, there is a T cell immunity that is generic and a mutation in the binding site does not change that, ”referring to cells that kill infected cells and prevent the virus from spreading.
Increased surveillance through genomic sequencing could also help the country find the “ideal variant” for a natural vaccine for Covid-19.