Can Delta Plus Variant Lead to 3rd Wave? Q&A With Dr Shahid Jameel
"You can think of it as two variants of concern coming together," says Dr Shahid Jameel on the Delta plus variant of the coronavirus.
A recent government decision to term Delta Plus variant as a 'variant of concern' has led to fears the mutation could possibly lead to a third wave. States like Maharashtra have already attributed a rise in number of cases to this variant.
What makes Delta Plus variant, also officially termed as AY.1, a more concerning mutation? How could it possibly impact vaccines? And how has the government reaction to the variant been so far?
FIT speaks with Dr Shahid Jameel, virologist and director of Trivedi School of Biosciences, Ashoka University on India's response to Delta plus.
What is the Delta variant? Why Do we need to be more worried concerned about Delta plus than the already present Delta variant in India?
We already know that the Delta variant fuelled the second wave in India. In the backdrop of Delta, a new mutation has come out. If it was any other mutation, it would not be worried so much. But this particular mutation, K417N, is the mutation earlier seen in the Beta variant found in South Africa. And we know from studies from various trials there that vaccines have not worked as well against the Beta variant.
Because this was a mutation that was originally seen in Beta variant and how is seen in Delta variant, that is a matter of concern. You can think of it as two variants of concern coming together. Now, whether the effect of this is going to be neutral, meaning no increase in transmissibility, or whether it will lead to further immune evasion, or whether the effect will be additive, or if the effect is going to be more than the sum of parts, is something that we don't know yet.
Now, calling something a variant of interest or concern is nomenclature that is decided at the level of the WHO, but since this mutation has come up in something that was already a variant of concern, it is logical to also call it a variant of concern.
How are the current vaccines working against the Delta variant and if this new variant can have an impact on them?
There are two ways to check this. One is to carry out laboratory tests on the serum samples of those who have received the vaccines and see if they still neutralise the virus. Some of these experiments have been conducted and they show that there is a bit of a reduced neutralisation of the Delta variant with both Covishield and Covaxin.
A more important analysis is the real-world population analysis. Two important real-world studies have come out in India, and those show that while the effectiveness of single-dose vaccine against symptomatic infection is 40-50%, that number goes up to 60-70% with two dose vaccines. Against severe disease and hospitalisation, that number is even higher.
With the two variants, people may get infected a little more, but they are still being protected against severe disease, and that is a very good outcome.
Similarly, Public Health England has done studies with both the Pfizer and AstraZeneca vaccines, and their results also show what we see in India.
Should we bring down the dosage gap between two doses of Covishield from 12-16 weeks to 6-8 weeks in light of the new variant?
Any policy has to be driven by evidence, and this outbreak is moving so quickly that often what we know today may not be relevant tomorrow. So policy must reflect that.
If everything was fine and vaccine supply was coming through, then 6-8 weeks would be ideal, but the question really is, if enough doses are not coming through, what strategy should you use? Should you give partial protection to a large fraction of people, or should you give the best protection to a small fraction of the population.
Now from a public health perspective, and with data coming out that Covishield is giving at least 70 percent protection with a single dose against severe disease, the current policy is fine. But as more doses become available, this policy should be revisited.
Is India's genomic surveillance too slow to keep pace with variants? There is constant criticism that we are sampling too little.
You can look at any problem as glass half full or half empty. By December 2020, India was sequencing at the rate of 0.05%, roughly 10 million confirmed cases, we had roughly 5000. Since INSACOG came together, sequencing started in a more targeted manner. it is important not just to sequence, but to also connect that sequence epidemiologically so you can make a public health decision based on it.
At one point we were sequencing at 1%, but when the second wave hit, it wasn't possible to sequence even at 1%, forget the 5% suggested by the WHO.
INSACOG labs are not sequencing more strategically, and it was their sequence that led to the discovery of the Delta plus variant. We are now sequencing cumulatively at 0.1%.
INSACOG now also includes 17-18 other labs, and it is a consortium made up of 28 labs now.
In an ideal world we should be sequencing at 5%, but we don't live in an ideal world. There is a lack of capacity in how many sequences you can generate on a daily basis, sequencing is an expensive exercise, so it is also a matter of resources, and also remember, the whole world is using reagents from the same sources, so there is also some supply issues of reagents. But I think for now what is happening is fine.
Is the government reacting more proactively this time to the newer variants? Do you anticipate a repeat of what happened before the second wave when warnings were ignored?
I think serious steps are being taken. There are regular press releases informing us about what is happening. We all make mistakes and we should learn from our mistakes. I think there is a very positive development that we are on it in a very proactive manner.
Could the Delta plus variant possibly lead to a third wave?
It is very hard to say. Delta plus could fuel a sort of a third wave only if it turns out to be far more infectious than Delta that is circulating in the population. And from the signatures of this virus, theoretically I don't see that happening. But then we need to keep a watch on it and see how it moves in the population. That is very important.
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