After concerns being raised by Gujarat and Madhya Pradesh over lethal strain of COVID-19 virus, experts engaged in genome sequencing call it too early to jump to any conclusion. India needs to scale up work to better understand virus mutation, they said. Rakesh Kumar Mishra, Director, Centre for Cellular & Molecular Biology (CCMB) and Dr Anurag Agrawal, Director, Institute of Genomics and Integrative Biology spoke to TNIE’s Richa Sharma on various aspects. Excerpts.
Is there a severe COVID-19 strain in Gujarat and MP?
l RKM: They (doctors) are suspecting more lethal kind of strain in Ahmedabad and Indore based on more deaths. But that is not likely the case as there is no scientific evidence and data. First, you need a larger number (of samples) to make any conclusion and you have to rule out that those patients have co-morbidity which is the case in most of the deaths. It needs to be validated properly. Isolate (the strain) from these patients needs to be sequenced, if there is any signature in terms of mutation which is not there in other isolates, which are so-called less lethal.
l AA: There is no reason at this point to believe that we have a special virus strain in India that is either weaker or stronger. Specific sequence from cases in Indore has to be done to understand — it can become weaker or stronger. There is nothing very significant so far. Of course, there are lineage differences but nothing on the line of something very severe or mild strain. So far, at the pan-India level, strain in India has more or less matched the strain from around the world.
What is the prevalent strain in India?
lRKM: We have found virus mutation which is unique in Indian strain, but they are not unusual and do not arouse suspicion immediately about any unique feature. The number (genome sequencing) is small, so we will have to wait for few more days. Once our data comes, more like couple of 100s, then we will be able to make better conclusion. Now, it is too weak to make conclusion what we (strain) have and what we don’t have.
l AA: Actually, it is impossible for India to have a very different strain because most of our cases came from abroad. Effectively, they brought those strain and it is mixture of strains from all over the world.
Is there slow progress in full genome sequencing as India has done only 35 (April 26)?
l RKM: Availability of sample is an issue and these need to be freely available, but it is not easy as it is infectious and paperwork needs to be done. Another reason, most of the time when you get sample, the number of viral particle are small and you need special technique to increase the number. But things are being streamlined from 10-12 sequence in a week, and we will be able to increase the numbers in coming weeks.
lAA: One word of caution. Looking at sequence to determine the severity of strain must be followed by actual experiment because these are computer predictions. It is important to know that something has changed but one must verify that.
Are less number of people being tested for COVID-19?
lRKM: Maybe around 60 per cent are asymptomatic and we never know how much they will spread. More testing need to be done for that will help as instead of locking down the entire country, we can specify and lockdown specific areas.
l AA: The total number of people infected will be more than those tested. We will not know until we do surveillance testing and that is what ICMR was trying to do. If antibody kits had worked better, we would have the results but they are trying to work out. They are trying to get us better data to understand the prevalence of infection and expand the testing base.