Breakthrough infections not a symptom of vaccine inefficiency: Soumya Swaminathan

Questions abound when it comes to the Coronavirus and the path it will take in future. As Chief Scientist at the World Health Organisation, Soumya Swaminathan is well placed to respond to them. In a free-wheeling chat with Hindu BusinessLine , she talks about the third wave, threat of a mutant that can outfox existing vaccines, breakthrough infections and the possible need for a booster dose. Excerpts:

Do you see a third wave as far as India is concerned?

There is no certainty and there is no way of predicting whether and when there will be a third wave. As you know, after the second wave, the case incidents came down, but it has settled down in the baseline of 35,000-40,000 cases a day, and it’s been stable at that level for several weeks now.

The factor that will influence a possible third wave is the level of immunity in the population. Today, we know that a significant proportion of Indians has been exposed to the virus. According to the ICMR serosurvey, it is 65 per cent. Plus, vaccination, 30 per cent of the population have at least received one dose and those who have received two doses is less than 10 per cent. So, there is some amount of immunity in the population, which should be beneficial.

We will see a continuing transmission state with localised ups and downs in places, as the virus moves through a population looking for more people to infect. I don't anticipate that we will get another wave like we got in the second wave.

How real is this threat of mutants which can elude existing vaccines or re-infect people?

It’s a very real threat. We have seen how these variants are emerging and each variant seems to have certain properties which give it some advantage over the previous variant. We are lucky that vaccines are still able to protect us against all the existing variants. Alpha, Beta, Gamma and Delta – the four variants of concern. But there are still a lot of unvaccinated people and that’s the kind of scenario where the virus can actually evolve and mutate to its advantage. Therefore, the threats of new variants emerging is always present and that’s why the whole push to vaccinate people as quickly as possible.

Among the vaccinated population, there are breakthrough infections. How does one deal with this?

People have to understand that the main goal of the vaccines is to prevent people from getting severely ill from this virus. It would have been an added advantage if vaccines could prevent transmission and some of them do, but they don't cause sterilising immunity.

So, when people talk about breakthrough infection, they are mainly talking about symptomatic infections. But in every country currently witnessing a surge, the majority of the people landing up in hospital are the unvaccinated. The majority of deaths are from the unvaccinated, so it is very clear that the vaccines are extremely effective in preventing severe disease. So the breakthrough infections should not give us a false idea that the vaccines are not working.

Your views on mixing vaccine doses?

India has only given approval for a trial of mixing Covishield and Covaxin. I think it is very good because we actually need more data, and the advantages of mixing and matching is that if you run out of supply, you can rely on different vaccines. Also, there is a possibility that different vaccine platforms might stimulate the immune system in different ways, so it might actually end up being beneficial.

But, we don’t know about the side-effects that could arise or any other kinds of risks that could be there. We have seen some countries using AstraZeneca followed by mRNA vaccines, but we need more research on vaccine mixing and then the data from those studies will feed into the policy.

Developed countries are considering booster doses. Will this come in the way of the world winning over the virus?

The WHO had a consultation on the need for boosters on Friday. As of now, countries which started vaccinating in December/January such as the UK, Israel, the US, there is no indication that the people who received the vaccine early are now getting sick. So, the conclusion really was there is no reason right now to rush into booster doses for the general population because we do not have the evidence that immunity is waning after vaccination and that it needs to be boosted. FDA (Food and Drug Administration) and CDC (the US Centers for Disease Control and Prevention) have allowed a third dose for people who are immunosuppressed. There have been studies that show that they don't develop antibody responses even after two doses. The third dose, in these cases, is part of the primary series not a booster dose.

Our goal now really is that 10 per cent of the population of every country should be vaccinated by September, 40 per cent at the end of the year, 70 per cent by the middle of the next year. To do that, the available supplies have to be distributed fairly and equitably around the world. That’s at risk now. There are no scientific reasons to give boosters. Secondly, it is ethically wrong to deprive somebody of primary course of vaccination, while some countries keep a stockpile of reserves for a booster that is going to be needed in the future.

The entry of Pfizer and Moderna’s vaccines into India is reportedly delayed due to concerns over indemnity.

I am not aware of the discussions that are taking place between government and companies, but what we did at COVAX was to agree on some common indemnification language, which the companies agreed to and which makes it easier for countries to sign up. But over and above that, we know that Pfizer, particularly, and maybe Moderna also, have certain conditions which they are asking countries to agree to for protection beyond the indemnification and that is where discussions are going on between companies and the Indian government.

Was India’s strong second wave because of existing NCDs (non-communicable diseases) like diabetes and hypertension, as a recent Lancet study has suggested?

From the beginning it has been known that these underlying NCDs like diabetes, hypertension, kidney disease, cardiovascular disease as well as dementia make you more susceptible to severe disease. I think the takeaway message for us is that we have a huge burden of NCDs in India and with or without Covid, we need to address it. NCDs are the major reason for primitive mortality in our country. We need to address prevention and early diagnosis and management of NCDs.

Are you worried about the Delta plus variant?

First of all, ‘Delta Plus’ is a name that is given locally. It’s Delta plus a few other mutations. It doesn't seem to have any features which make it more dangerous than Delta. So, we do not consider it as a variant of concern.

When do you see Covaxin getting recognised globally?

Bharat Biotech provided the first set of data that was uploaded around July 19th. Last week, they provided additional data to the committee. I think the initial review of the dossier has been done and the additional data needs to be reviewed and the technical advisory committee as far as I know will meet sometime in the first week of September. So, the timelines are looking like mid-September to me for the decision on Covaxin.

Bharat Biotech is also developing a nasal vaccine, Zydus Cadila an intradermal vaccine - your thoughts on these different delivery systems?

It’s very good to see these alternate delivery systems, particularly the intranasal route and the intradermal route. The preliminary Phase I data looks good in terms of antibody responses. So, we need to wait for the results of the Phase 2 and 3 clinical trials and the same thing for the intradermal vaccines as well. There are advantages in going away from injectables in terms of ease of administration, vaccine hesitancy may reduce, costs will hopefully come down and healthcare workers need not be trained to that extent to be given injections. But it’s a bit premature to say whether these are as safe and efficacious as the vaccines that we have now.

There is one other thing that I wanted to say here. Whatever vaccine candidate, it must go through properly conducted randomised trials with an active comparator. Otherwise, none of these vaccines will gain global acceptance. So I think that it is really important for the regulators to ensure that the trials done in India are well designed and conducted so that the vaccines get global acceptability.

How has Sputnik’s application for an emergency authorisation progressed?

In fact, Sputnik submitted their data even earlier than Bharat Biotech, but there were lot of questions that the committee has asked and so they are yet to provide complete data and also there was an on-site inspection done of the production facilities in Russia and they were some serious concerns from one of the production facilities in terms of manufacturing practices and that has been highlighted. That was only in one of the sites in Russia. So, Sputnik I would say is further behind than Bharat because the data set is not yet complete.

When you met Union Health minister last week did you get an indication on when India might start exporting again to COVAX?

Yes, we did discuss that, and the fact is that a large part of the world actually depends on Indian manufactured vaccines, particularly COVAX. The minister said that India is very committed to supplying COVAX and to low-and-middle income countries (LMIC) through COVAX and as soon as the supply situation in India is sufficient to meet the domestic needs, this will resume, and we are probably looking at the fourth quarter of this year. So, either October or November is what was indicated.

That’s quite close from now..

Yes, it is and I was very happy to hear that.

What will be your advice to the Government of India going forward to ensure that even if there is a third wave it is completely manageable?

The first is obviously to expand vaccination as quickly as possible and I would say vaccinate the vulnerable first-the 45 plus age group should be covered as rapidly as possible, because most of the severe cases and deaths are going to happen in that group if at all there is a future wave. Also, one needs to look at granular data. Elderly/ vulnerable populations, geographic areas which had less exposure of the virus in the past, and lower vaccine coverage should be prioritised.

Second is to strengthen the healthcare system. This is not just in terms of making sure that there is oxygen and other supplies. Focus on rural areas. Delta swept through the big cities and 80-90 per cent of the population in these centres now have antibodies. It’s the smaller towns and villages that are at higher risks. So, beefing up the health system in the rural areas is critical.

The third would be to keep a close eye on the indicators that will warn us of an impending wave - like R0, test positivity rate and so on. We also need to make sure the testing rates stay very high so that we are not missing the cases.

Then, we should maintain all the public health and social measures like mask wearing and physical distancing.

Do you think it’s a good idea to open schools when those below 18 years are yet to be vaccinated?

I firmly believe that children being out of school any longer is going to have an irreversible impact on a whole generation of our students, particularly, those who come from the underprivileged sections of the society. Children do not need to be vaccinated before reopening schools. There is no country in the world which has waited for children to be vaccinated. We know that children who get infected, get only a very mild case of symptomatic illness. In fact, two-thirds of children in India are seropositive, says ICMR’s sero survey. So why keep millions of children at home?

When do you see the Covid situation improving from the way it is?

Today, we still have 8,000-plus deaths a day that is really very sad and unacceptable. These are just the reported Covid deaths, the actual numbers of deaths will be much higher. That situation needs to change, and we can do it by vaccinating the 20-30 per cent of the population that we know is at the highest risk. So, if we do the 40 per cent that the WHO is saying, then we will be in a very good position by the end of the year.