People wait to receive a dose of Covishield at a hospital in Noida, August 30, 2021. Photo: Reuters/Adnan Abidi
- The Indian government hasn’t been able to generate adequate data on booster doses at the right time, choking an important decision.
- The omicron variant, especially its transmissibility, could increase the cost of a delayed policy in a bad way – especially for vulnerable individuals.
- Other causes for concern are unavailability of mRNA vaccines and a potential surge in the number of people with mild or moderate infections.
New Delhi: With the emergence of the omicron variant of the novel coronavirus, quite a few scientists in India are now saying that the time has come for the country to roll out booster doses for COVID-19 vaccines, at least for a part of the population – even if some of them were not too long ago receptive to the idea.
To make sense of India’s need for booster doses and the factors that could influence the Indian government’s decisions on this front, The Wire Science spoke to virologist Gagandeep Kang, who is also a senior faculty member at the Christian Medical College, Vellore, and a member of the National Technical Advisory Group on Immunisation (NTAGI).
(Kang clarified after the interview that she doesn’t speak for NTAGI.)
Excerpts from the interview are presented below, with light edits for clarity and style. The Wire Science’s questions are in bold and editor’s clarifications, in square brackets.
You had consistently maintained, for a long time, that there wasn’t enough evidence to roll boosters out en masse. Do you still have the same opinion?
There was no data earlier for a mass roll-out but I had always said that those who are immunocompromised needed a third dose. That is now urgent, all the more.
As far as boosters are concerned now, data from the UK, the US and other parts of the world clearly shows that two doses of the AstraZeneca vaccine and of mRNA vaccines aren’t enough. So we really need to think about boosters.
The other thing that I keep emphasising is that we need to be thinking about protein vaccines and mRNA vaccines, made by Pfizer or Moderna, either for primary immunisation (i.e. the two doses) or as a mix for people who have already received Covishield or Covaxin.
So what do you think is holding the NTAGI back on taking a call on booster doses?
One decides on boosters based on data. What you are looking for in the data is how well vaccines are working among different age groups against different outcomes like death, severe disease and hospitalisation.
Now, we have one vaccine tracker maintained by the Indian Council of Medical Research. If you look at it, all it says is vaccines are working fantastically well against deaths, with a break-up of age groups. That’s it. Where do we look for other parameters mentioned above? Plus the tracker doesn’t say which of the two vaccines prevented how many deaths, what the locations of data collection were, and so on and so forth.
Is the absence of evidence being treated as evidence of absence?
Yes. Moreover, this tracker was last updated in October-end, by which time 34% of the population was fully vaccinated. Now, this is a huge backlog. This data still remains incomplete, to [be able to support taking] a call on boosters.
Is there really no other source for independent scientists, say, like you, from which to obtain granular data on India’s vaccination?
No
Would I be correct, therefore, to say that we didn’t collect the right data at the right time to be able to make important decisions?
Yes, and we are repeating the same pattern again.
Considering the omicron variant is an impending threat, how fast do we need to decide?
Really fast. And if we were to roll out boosters, they have to be [assigned] first to those who are immune-compromised, followed by the elderly [aged 60+ years] and then healthcare workers.
CMC Vellore recently rolled out a trial on booster doses. In the trial, participants who have already received two doses will be administered a third dose. Here, what combination of primary immunisation, i.e. first two doses, with boosters are the researchers planning to study: Covishield/Covishield, Covishield/Covaxin, Covaxin/Covaxin or Covaxin/Covishield?
All these combinations are going to be looked into, in this multicentre trial. We expect to complete recruitment by December-end. The recruitment of participants with Covaxin is a bit of a problem because it is difficult to find those who took this vaccine, as more than 90% [of all vaccine recipients] took Covishield. [Once recruitment is complete] it will take one month to generate lab results.
mRNA vaccines are not part of the study protocol. This is important, as a UK study has shown that if two doses of the AstraZeneca vaccine (made in India as Covishield) were topped up with an mRNA vaccine, it resulted in an overall effectiveness of 71% against infections of the omicron variant.
We really wanted this. When we got the study approved by the Drug Controller General of India in August, I was hoping that we would have mRNA vaccines in India, because Moderna’s jab had been approved by the government and we were hopeful. [India is yet to receive a single dose of the Moderna vaccine.] Ultimately, we are where we are – with Covishield and Covaxin.
Also read: How Many Indian Health Workers Have Lost Their Lives in the Time of COVID?
The UK study reported that the omicron variant could become the dominant strain there by mid-December, taking over from the delta variant. Have there been any similar modelling exercises in India?
The number of cases is too small in India at the moment to say so.
From a public health perspective, and not just as a matter of scientific trials, should India already have mRNA vaccines?
It should have happened. We needed mRNA vaccines. To offer the best to Indian citizens, we should have looked at all platforms, and so far it looks like having an mRNA vaccine in the mix is giving the best result, especially in the light of the omicron variant.
About our preparations: If we expect the omicron variant to spread significantly in India, what are the things we need to do right now?
It took just 100 cases in the UK for the disease [caused by the omicron variant] to really take off. Will that happen in India? For that, we have to really strategise our testing well, and not just test more and more. You can’t test everybody everyday. If I have to look for actual disease spread, I would do more stringent testing in hospitals compared to what is being done in the community.
Then the issue is the purpose of testing – which is beyond finding whether somebody is positive [for an infection of the virus] or not. A large number of tests, for example, is taking place at airports. What will we do with this data? How does it fill gaps in the big picture? How does it help formulate an action plan? And this holds true not just about airport data but about hospital data, too.
How should this data be used?
Data feeds into […] plans. Why do we need severity data? How many hospital beds are going to be required? How many will require supplemental oxygen? How many will require ICUs? Is [the infection caused by the omicron variant] milder than other variants?
If the omicron variant is going to take over in the Indian population from the delta, are hospital requirements likely to be different as well?
So in the case of the delta variant, we knew 80% of cases could be managed at home and 20% required hospitalisation. Out of this 20%, 10% would do well in regular wards with a bit of supplemental oxygen and 3-4% would require ICU care.
Now, if the omicron variant causes milder disease, as the preliminary data shows, then maybe 85-90% [of cases] can be managed at home and the rest will require hospital care. So these are things you need to be able to build on for planning on healthcare preparedness.
But still, those 80-85% did require some sort of medical assistance. And the mild cases couldn’t receive such assistance during India’s second outbreak, leading to a lot of chaos. If existing data is anything to go by, we will have a large fraction of mild cases, so don’t you think we will need to think about them more, instead of brushing aside the fact that they are just mild cases?
Oh, absolutely. Two things are important to remember. A large number of patients with mild and moderate disease can overwhelm healthcare systems when there is an unexpected demand. So there is an added pressure on the system and the people managing it. This requires planning.
Second, even if, say, 50% of cases were already infected and also doubly vaccinated, there are still another 50% who are not doubly vaccinated and/or infected. Therefore, a large part of the population will still be susceptible, and in absolute numbers this may be a very large group.
You talked about testing earlier. Our RT-PCR kits look for three genes, including the S-gene, which is absent in the omicron variant. But only a fraction of RT-PCR kits in India seem to be able to detect the absence of this gene. How big of a challenge is this?
This is a concern. In the case when you have a shortage of RT-PCR kits that can detect S-gene drop-out, then ramping up genome sequencing is the only way out, to know the true spread of the omicron variant.
Also read: This Is What We Know So Far About the Omicron Variant
Any thoughts on paediatric vaccination?
They can be given to 16-17 year olds if we have extra supply.
But not to younger people?
If vaccines are licensed and if it gives parents a good feeling – go ahead, but only if vaccines are available in more quantities than are required, to continue immunising the eligible population.
Last: there have been quite a few studies now, admittedly preliminary, on important aspects of the omicron variant’s evolution. Could you summarise your takeaways from these studies?
Transmissibility: More or equal to the delta variant. Reinfections: Definitely more. Immune escape (after two doses): Definitely more. Severity/virulence: Possibly the same or lower.