Dr Shahid Jameel, virologist and director, Trivedi School of Biosciences, Ashoka University, tells that the UK variant, though not found to be more lethal, could still cause more deaths in India. Excerpts:
Q. The detection of new SARS-CoV-2 variant seems to have triggered widespread concerns in India. What makes this particular strain different and significant?
Mutations in viruses leading to new variants are normal. Most mutations are harmful to the virus. Only mutations leading to variants that can spread better are visible in a population. The first time this happened to the SARS-CoV2 strain from Wuhan was when a Spike D614G variant emerged. On January 1, only 5% viruses in circulation were the G variant. Now, 100% of the circulating viruses are the G variant. It happened because the viral variants with G at 614 position in the Spike protein infected cells better than those variants with D at the 614 position. One variant out-competed the other.
The variant in the UK carries 23 mutations compared to the Wuhan strain. These include 17 non-synonymous and 6 synonymous mutations… Of the 17 non-synonymous mutations, 8 cause changes in the Spike protein. Among these, two (N501Y and P681H) are now seen in 24% and 16% of viruses circulating globally. For the first time both of these mutations, and another called 69-70del, came together in the UK variant, called lineage B.1.1.7. The result is a viral variant that is out-competing others.
Q. In terms of public health, what could be the implications of this development? Could the Covid-19 pandemic take turn even for the worse in the coming weeks and months if the mutant virus leaks into the community?
So far the UK variant is only found to spread faster – exactly how much faster is not known for sure. There is no evidence that it causes disease that is any worse or different from that caused by other variants. However, if the virus has become more contagious, it will infect more people, and even at the same per cent severity and mortality it will cause more numbers of severe cases and deaths. This is one cause for worry. The other cause for worry is whether these variants might escape the vaccines being made. There is no evidence for that. In fact, unpublished results shows that the UK variants are effectively neutralized by serum from people who have recovered from Covid-19 earlier in the year, before these variants were discovered. This is good news.
There is no reason to believe that the UK mutant is not already in the community. More such variants will be discovered in India. Importantly, there would be similar homegrown variants. After all, India already has over 10 million confirmed cases and possibly 150 to 200 million infections.
If we are not careful with the measures available to us – masks, distancing and sanitization – there is every reason to believe that numbers may spike in the coming months.
Q. What steps do you the government should take as immediate measures to tackle the situation? Also, what is your view on the genomic surveillance exercise undertaken to monitor Covid-19 virus in India so far?
Closing airports is a short-term measure and it will have diminishing returns. By the time you do it, viruses would have already slipped in. We saw this earlier in the year and we see this again. Contact tracing of everyone who has come in from UK between October and now will be difficult and impractical. Further, this still does not address homegrown variants. Instead of being reactive, the government should spend its resources and energy on two key proactive measures. One of these is increased genomic surveillance.
The WHO recommends sequencing one after every 300 cases (0.3%); India’s genomic surveillance rate is around 0.05% and that too is restricted to urban areas where sequencing labs are located. In India we have sufficient expertise in both sequencing and data analysis. Put together a consortium of labs that will get samples from across the country. Let us sequence around 5% cases. This will give us dense and granular data to help policy makers prepare for the future. It will also help detect any vaccine escape variants that will emerge in future when vaccines are deployed to large numbers of people.
The other thing is transparency (which increases trust) and good communications to let people know that we are still in a pandemic. The constant messaging about falling numbers and low mortality in India have made people complacent. The only way to prevent viruses from mutating and producing more effective variants is to limit transmission.
The only tools available to us for this are masks, distancing and sanitization. Even after vaccines come, we must continue to do that, at least all of 2021.