'Even Once Vaccinated Against COVID-19, Don't Let Your Guard Down'

The reasons for India's falling COVID-19 infections are still being investigated. But is COVID-19 truly slowing down, and will it keep slowing down? How is the disease spreading now in cities such as Mumbai that still have a comparatively higher case count? Are hospitals--the frontlines of the COVID-19 war--seeing different kinds of cases, with the emergence of mutant strains of SARS-CoV-2? Om Shrivastav, consultant infectious diseases specialist at Jaslok Hospital in south Mumbai, and Kiran Shetty, critical care medicine consultant at Kokilaben Dhirubhai Ambani Hospital in north-west Mumbai, talk to us about India's current COVID-19 scenario.

Edited excerpts:

Dr Shrivastav, is there anything different in the way COVID-19 is manifesting in patients today, compared to three or six months ago?

What is different now, for one, is that the total number of people who are getting infected, and people requiring hospitalisation, is much smaller. It's down to a trickle. There are still COVID-19 infections, and patients needing intensive care, but nowhere close to the number that we were seeing even just a couple of months ago. Also, the people who do need to come to hospitals now are a bit sicker than earlier patients. This is probably because the COVID-19 strain that came from the United Kingdom (UK) is a little more infectious, and, as of now it appears more people seem to need hospital care. They don't necessarily all need ventilators, but they do require treatment. So the total number of people getting infected either through travel or close proximity is still significant. That can't be trivialised.

Whether cases will remain low, we will know in a few months' time. Hopefully, things will stay this way. However, this situation has to be watched carefully. I don't think anybody is in a position to make a prediction about how the COVID-19 virus is going to behave hereon. But certainly, people who are in the healthcare system will be watching it very carefully, and people in the public health system even more carefully. So maybe in about two or three months, we will have a much better idea of where the virus is headed.

Dr Shrivastav, you mentioned exposure to people who've arrived from abroad. That was exactly the case in the second half of March and April 2020. The COVID-19 virus came from overseas; it travelled the globe. So, are you able to see where or how people are getting infected now, as opposed to a few months ago, when it was clear that you could be anywhere in the cities of Mumbai or Delhi or Kolkata and you could get infected?

I'm not really at liberty to discuss exactly where we think COVID-19 infections are coming from, because this is data that will be shared by the government of Maharashtra. What I can share with you is that COVID-19 cases are coming from much smaller pockets than in March or April 2020.

Dr Shetty, how are you seeing the progression of the COVID-19 disease and how it is manifesting, particularly in the last few months, from your vantage point as a critical care specialist?

I completely agree with Dr Shrivastav that it's too early to say that because the number of infections has dropped, it will stay that way. But in terms of intensive care, cases have dropped drastically. Our ICU occupancy has dropped to a third of what it was when we were at the peak. That's probably because of India's demographics. Younger patients are probably tolerating COVID-19 better at this point as serious symptoms are not really manifesting in younger patients. The really unwell patients are the elderly and those with comorbidities or illnesses that predispose a person to severe COVID-19. That hasn't changed. We are still getting very unwell patients who have chronic kidney disease, or diabetes, or are obese.

Dr Shetty, where would you think most COVID-19 patients that you are encountering now are getting infected, and how are they contracting the disease?

We can't really pinpoint where they are getting the disease. The patients we are seeing now are the ones who were always vulnerable to COVID-19 infection. It's the really unwell patients who are coming to hospital, so I don't think there's a particular area from where they are coming.

Dr Shetty, the latest seroprevalence data make it clear that very large numbers of Indians have already contracted COVID-19. Any thoughts on how and why this has happened?

Partly it's to do with increased awareness about the disease, because of which patients are going to the hospital much earlier to avoid getting to the point where they may need intensive care. That may be one of the reasons why we've seen a lot of young patients with symptoms coming to hospital now who may earlier have stayed at home, and come in only on day 10 or 12 and ended up in intensive care. That's not happening anymore.

Dr Shetty, has the COVID-19 treatment approach that you are using changed in any way in the last three or four months?

It's not really changed, but I think we have now fine-tuned who requires what kind of treatment, when to give what medication, whether we need to think of instituting steroids or use remdesivir or plasma, when to do a CT scan, etc. Each hospital now has well-set protocols when a COVID-19 patient comes in, and that also seems to have helped, because fewer patients are getting really sick. Even if they end up in hospital, they just need one or two litres [of oxygen], and then they get better.

Dr Shrivastav, if you look at the seroprevalence surveys, many people have already contracted COVID-19 in India and, as an economist told me, this virus has already swept through the country. Have we now developed fairly high levels of immunity, or almost herd immunity, which is why you are not seeing as many cases?

I'd like to make a couple of points about herd immunity and antibody levels. Herd immunity means that two-thirds of the general population should have antibodies. But which antibodies? The antibody that you're looking for is a neutralising antibody. That's important. It's not just a matter of doing a blood test and saying 'yes, I've got a positive result for Immunoglobulin G levels of antibodies'. The antibody must be a neutralising antibody, and that neutralising antibody needs to be in the patient's system for longer than two or three months. Else, it is conferring no protection to the patient. So it's not enough to say 'yes, I have looked for antibodies and the antibodies are there'. It's important to find out how long these antibodies are going to last. I think that before we make any comment that immunity is here, we need to wait and see where the COVID-19 story is going to be unfolding in the next six months' or year's time, or maybe even two, three or five years' time. Because COVID-19 is a viral infection that has swept the whole globe. And we know it for less than a year's time. So for anybody to say 'yes, I know enough about COVID', that would have to be a very brave person.

I don't think we know enough to say 'yes, this is how the virus is going to be behaving'. I wouldn't venture to be in that position because just about everything that we know now is going to be unlearned tomorrow morning. There will be a fresh set of evidence that will show that what you thought you knew yesterday evening is going to be junked today.

Let's say people have a certain degree of immunity, as per what the seroprevalence studies are saying. At another level, adherence to safety standards, such as the use of masks, seems to be high. So, which is working more, immunity or safe practices? Or are both together leading to the lower number of infections we are seeing today, Dr Shrivastav?

If you were to pick any one measure since COVID-19 started that has saved lives, day in and day out for the last 10-12 months, it would have to be the use of masks.

When we first started learning about COVID-19, we would say that the people who are at the highest risk are those with certain health conditions. We now know, for the past four or five months, that the people who are at the maximum risk are the elderly, and the obese who have a body mass index greater than 29. These are the highest-risk sections, not just for getting COVID-19, but also for getting complications of COVID-19. These two sections need to be watched the most carefully.

Dr Shetty, about the COVID-19 virus mutation you have referenced, do some of the patients you are now seeing have the new mutations, whether from the UK, South Africa or elsewhere? And if so, how are these cases playing out clinically? Are they any different?

Clinically, at least in terms of critical care, we haven't seen anything different. We're seeing more or less the same sort of trajectory with cases. I don't think clinically, one can really pinpoint and say that this case is probably a mutant strain or the original COVID-19 strain. I don't think we've reached that point yet, given the numbers that we've seen of the new strain. Also, a more infectious strain doesn't necessarily mean that the severity of the illness increases. For all you know, it may be less severe.

Dr Shetty, you said that COVID-19 cases requiring intensive care have reduced by a third. Are you seeing cases of other diseases or conditions rise, and if so, is there any correlation with the imposition of the lockdown?

Not really. Our ICUs have been as full as they were earlier, so I don't see a dip or a rise in other non-COVID-19 cases. However, earlier there was probably an apprehension among people [of getting infected with COVID-19] should they visit a hospital. People who would manage certain symptoms at home are now coming to hospitals. The only thing I would want to point out is we've hardly seen any cases of dengue this year. That's very surprising. I don't know whether it is related to the COVID-19 virus. I read an article somewhere that there is a fight between the viruses and humans are collateral damage. But we've hardly seen cases of the main tropical diseases like malaria and dengue in the post-monsoon period. That could probably boil down to less construction work happening because of the lockdown, and less exposure to stagnant water. That would be a takeaway from me.

Dr Shrivastav, given where we are now in terms of falling COVID-19 cases, people are feeling confident, the economy is looking up, the stock markets are doing well. This is also the time when people may start taking things easy. What would be your advice to our readers on how to deal with and treat this virus, as an individual? Going forward, what else should we be looking out for?

On a lighter note, the one thing that has definitely happened in the last couple of months is that people have all turned into teenagers. Everybody wants to party and party hard, as if there is no tomorrow. Make sure that you do not let your guard down, and make the use of masks a way of life now. Also, don't disregard symptoms and don't treat yourself. Whatever symptoms you may have, however trivial they may appear at the time, do not make the mistake of treating yourself, because these are viruses that may be trivial to start with but will become nasty.

Take all the other vaccines that you would have, like the influenza vaccine. Do a blood test at least once in six months or a year. Make sure you have someone watching over these things. And follow as fit and healthy a lifestyle that you can. That should be your target.

Health and other frontline workers are being vaccinated against COVID-19. Can one let one's guard down while around vaccinated people? If I am vaccinated, should I stop wearing a mask?

You can't stop wearing a mask, because we know one thing for sure: Vaccinated for COVID-19 or not, you will keep shedding the virus. You may not even know that you're shedding the virus. So I don't think that recovering from COVID or getting the vaccine means you should let your guard down. The strain that is circulating in your system may not be the strain that is covered by the vaccine. So, by all means, you must take the vaccine that is recommended by the authorities, or your doctor. There is just no way that you can say 'I've had the vaccine', or 'I've had the COVID-19 infection and I'm safe now'. That is a mistake that may be fatal.

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