The India Council of Medical Research (ICMR) on Tuesday warned against indiscriminate use of experimental therapies in treating patients of the coronavirus disease (Covid-19) , saying it puts too much immune pressure on the Sars-Cov-2 virus, causing it to mutate faster.
The warning comes in the backdrop of the discovery in the UK of a new variant of the virus that causes Covid-19. The new strain, scientists say, is more transmissible than the original one.
“The question arises why should these variations occur? These variations occur because of the immune pressure on the virus. The immune pressure on the virus may be related to the environment, may be related to the host, or may be related to your treatment, or may be related to other modalities which cause this pressure on the virus. Therefore, it is important from the scientific community perspective also that we do not put immune pressure on the virus,” said Dr Balram Bhargava, director general, ICMR.
Dr Bhargava’s remarks came at the government press briefing on Covid-19 updates on Tuesday.
Six UK returnees have tested positive for the new UK variant of Sars-Cov-2, according to the initial results of genome sequencing of positive samples released by the Indian Sars-Cov-2 Genomics Consortium (INASCOG) labs on Tuesday.
Three of the samples that came in positive for the new UK variant were from the National Institute of Mental Health and Neuro-Sciences (NIMHANS), Bengaluru, two from the Centre for Cellular and Molecular Biology (CCMB), Hyderabad, and one from ICMR-National Institute Virology, Pune.
“Also, why we have to maintain judicious use of therapies which are going to benefit; if their benefit is not established, we should not use those therapies otherwise they would put tremendous immune pressure on the virus, and the virus will tend to mutate more. Therapies that are well established should be used, and those that are not well-established their judicious use has to happen,” Bhargava added.
Critics of convalescent plasma therapy in the past had pointed out how its indiscriminate use could lead to significant mutations in the virus.
From November 25 to the midnight of December 23, about 33,000 passengers disembarked at various Indian airports from UK.
All these passengers are being tracked and subjected by the states to Reverse Transcription-Polymerase Chain Reaction ( RT-PCR) tests to detect Covid-19. Of all the samples tested, 114 samples have been found Covid-19 positive so far. These positive samples have been sent to 10 INSACOG labs for genome sequencing.
Bhargava said: “Genetic mutations occur in these respiratory viruses; and these minor drifts may occur from time to time. Once several drifts occur then they can become important and can become the variant as has happened in the United Kingdom, which has higher transmissibility of about 60% or so. That is a point of concern although we are testing in India for the variations regularly.”
Genomics experts, however, say there is not much of a change in terms of how the disease is handled after finding the new UK variant in India.
“It was always likely. Nothing changes in terms of what we need to do. Usual precautions will work well for this variant as well,” said Dr Anurag Agrawal, director, Council of Scientific and Industrial Research- Institute of Genomics and Integrative Biology, New Delhi.
Clinical microbiologists also say that the testing process will also largely remain the same in laboratories.
“Increased transmissibility means more people will get infected and since there are no implications on the pathogenicity, which is its ability to cause disease, it isn’t much of a concern. For Covid-19 detection the same RT-PCR testing will be conducted, and government’s surveillance system is already in place that will be conducting large-scale genome sequencing to check for the new variant. So nothing essentially changes on ground,” said Dr Navin Kumar, head of clinical microbiology and infection prevention, Manipal Hospital, New Delhi.