The Hyderabad based CSIR-Centre for Cellular and Molecular Biology is a premier science institute in the country, also involved in Covid-19 research since last year. In this interview with DH’s Prasad Nichenametla, CCMB Director Dr Rakesh Mishra throws light on the emergence of the virus strains in the country and the reasons behind the catastrophic second wave.
Excerpts:
We are amidst an unprecedented health crisis. What has caused this explosion in Covid-19 cases now heading towards four lakh per day?
The biggest contributor is our Covid-19 inappropriate behaviour. Viruses tend to mutate as they keep getting weaker over time. The UK variant and the Indian double variant might be a little more infective but the viruses have not gained the ability to fly faster, or travel through mosquitoes. The only way the SARS-CoV-2 still can infect is when we drop our guard, especially in crowded interactions.
Infections increased among the younger lot, as students mingled cheerfully with friends in schools, colleges after being restrained for months at home. And election rallies, religious gatherings, weddings, open bars, restaurants have accelerated the virus pace. What do you expect when people sit inside a theatre for three hours? The last couple of months the public behaviour is as if the virus got scared away by the vaccine news. When the fact is we are far behind in vaccine coverage of our population.
How many Indian origin mutant strains were discovered till now? And how lethal they are?
Three variants are of India origin -- B.1.617, B.1.618, and one sub-lineage of B.1.617
B.1.617 is popular as double mutation and the sub-lineage of 617 is known as triple mutation. This triple mutation is localized in Maharashtra constituting about 10 % cases. Triple variant is not given a specific name as it is similar to double variant with only one change in the virus spike protein.
B.1.618 is in Bengal, and is stable there for several months, in about 20 % cases. Over time, B.1.618 might disappear, with B.1.617 taking its place as it is expresses itself faster than B.1.618
One of the mutations in double mutant Covid-19 virus is L452R, first found in California. The Indian strain developed another known mutation – E484Q, and became a double mutant. Double mutant is not a case of two viruses from two regions coming together.
And when this double mutant developed another change at 382 position, it came to be referred as triple mutant. This double-triple nomenclature would be misleading, since each of these variants show over 15 mutations. More mutations does not mean the virus strain has become more dangerous. The Indian double mutant was first traced in October but our neglect over the past few months gave it an advantage.
There is a lot of anxiety about this mutant strain B.1.617, the Indian variant. Is this the major cause of the second wave in the country?
Not at all. Commonly known as the Indian variant, the B.1.617 was found in only around 35% cases in Maharashtra. The virus samples sequenced at CCMB showed B.1.617 in only 2% cases in Telangana and 5% in Andhra Pradesh. In Delhi and Punjab, it is the UK variant which is more prevalent. Unfortunately, there is not much genome sequencing of the virus samples in many states, but it seems in different regions, different variants are thriving.
The Indian variant is only as infectious as the UK variant. We are in an advanced stage of the second wave, but still the majority of cases are not of UK, double or triple variant type. From all the samples sequenced till now, the UK variant is found in 12-15% and the double variant in about 20%. So in about 70% cases, it is different strains.
The Covid-19 virus has expanded its footprint, but fortunately none of these variants are more dangerous in terms of symptoms, deaths, or in their reaction to vaccines. People should note that no virus, be it from China, UK, or India, can beat the strategy of wearing masks.
Since viruses have the habit of mutating constantly, how important is genome sequencing in dealing with the Covid-19 pandemic?
Genome sequencing, the process of determining the DNA sequence of an organism, helps us chart a particular virus strain’s journey like the UK variant carried from London to Delhi and Punjab. A constant genome surveillance tells us about the spread, mortality caused by a variant and if it is ignoring the vaccines. We need to keep testing every international passenger and sequence the positive samples. Such an effort at the Hyderabad international airport has helped prevent UK variant spread in AP and Telangana. Passengers determined by CCMB as infected by the UK variant were kept in single room isolation.
We also need to keep analysing samples from hospitals, areas reporting case burst, deaths apart from cases of reinfection, new symptoms, post-vaccine dose. Weekly surveillance in towns, villages, with samples covering all localities for sequencing, would give us an update on the virus transformations.
What should the governments have done to have avoided the tragic events evident today? What measures would avoid, or lessen a third wave intensity?
Restrictions should have continued, with social distancing, compulsory masks and constant testing, tracing and treatment of the positive cases. Election rallies, Kumbh melas could have been avoided. And in this past one year, we did not go much ahead in our health infrastructure improvement. However, the central government took a good, daring decision approving the vaccines for emergency use even when there was criticism stating lack of enough data on vaccine safety, efficiency (in Covaxin case).
We can say government could have done several things but we as public should have been careful. The bottom line in winning the war on virus is our Covid-19 appropriate behaviour. Let us remember that our negligence has earned us this wrath.