NEW DELHI: Dr Shahid Jameel, senior virologist and director of Trivedi School of Biosciences at Ashoka University, says the delta plus variant is one to watch out for. He also says India needs smart sequencing, focusing on areas where this has been found and areas where there is more transmission. Excerpts from an interview...
So far, nearly 40 samples with Delta Plus variant of SARS CoV 2 have been identified in India. What significance do you think it has for the course of the pandemic? So far, what is our understanding of this variant and should we be worried yet?
The numbers are still very small. Only about 200 sequences the world over and about 30 in India. At this time, it is something to watch out for. A precursor to what we know as the delta VOC (variant of concern) today was first seen as just a few sequences from Maharashtra in December. But it expanded rapidly to become the most prevalent VOC in India. Delta Plus has potential to do the same.
If it is established that this variant is capable of evading immunity and is resistant to existing Covid vaccines, what does it mean for the ongoing vaccination programme and what public health measures should be taken to curb its spread?
This is speculation at this time. Most vaccines in use are likely to work, but possibly with reduced effectiveness. If it turns out that delta plus spreads widely and if vaccine effectiveness is severely compromised, it may require booster doses. In India the most used vaccine is Covishield, but due to its viral vector background, a booster third dose is unlikely to be more effective. This is where mixing vaccines, especially using either RNA or protein vaccines as a booster, would be a better approach. We need those to be tested in small trials.
Under the current rate of genomic surveillance, do you think India we will be able to quickly identify emerging variants of concern?
It would be better to increase sequencing. However, Delta Plus was after all identified at this rate of sequencing. What is required is smart sequencing, focusing on areas where this has been found and areas where there is more transmission.
The pandemic seems to be stabilising in most parts of India, but what can we expect ahead? Do you see a threat of a third wave?
The third wave or rather localized outbreaks in different parts of the country would depend upon (a) wow we continue to follow Covid appropriate behaviour (b) how quickly we can vaccinate the susceptible population (c) whether a more transmissible variant develops. While (a) is based on individual choices and (b) is a matter of public policy, (c) is a random process whose frequency can be reduced by reducing transmission, that itself is based on (a) and (b). Therefore, individual behaviour and vaccination rate will determine the timing and magnitude of future outbreaks.
Since it’s almost certain that new variants will keep emerging, what role do you see for the ongoing vaccination drive? Is it possible for the vaccination strategy to keep up with the mutating virus?
Viruses don’t have an endless capacity to mutate. This virus, like many before, is adapting to the human population and on the way to becoming endemic. So far, all vaccines are showing reasonably good protection against serious disease, hospitalization and mortality.
Good vaccine coverage would be key to the control of this pandemic. We may in future need boosters against variants that evade the current vaccines. It is important to identify the emerging variants quickly and have a plan for booster vaccinations.