‘We need to understand our own ethnic genome better’

The discussion on vaccine efficacy needs to move from what percentage will be protected against the Covid virus to what percentage will be protected from death or serious illness due to infection, says MEHUL MEHTA, physician and chief medical officer at the Albright Stonebridge Group. In an interview, Mehta tells Anjuli Bhargava that picking up mutations before a spike in numbers is crucial. Excerpts:

What could we have done differently to reduce infections and deaths?

The numbers in India were rising till September and then there has been a dramatic drop. Experts thought that by December, the numbers would start moving up again but that hasn’t happened.

The fact that we expected a pandemic was obvious and known to anyone in the field and some outside of it. The SARS countries that had been burnt in the past had run preparedness programmes.

Second thing is that we could only prevent the spread once we understood its biology of transmission. So there was a lag that led to an exponential rise in infections and a pandemic as global travel exacerbated the situation. Third, the virus and its spread was not homogeneous. In fact 20 per cent are infecting 80 per cent of the population. Almost every country had its own seminal super spreading event.

Our testing was inadequate and remains so. India could have done better with testing and contact tracing. Once you knew what you were dealing with, public health mandates became critical. Like masking and social distancing became important.

Here India was fortunate.

Countries that had seen similar outbreaks in the past did better, as did those who followed the public health measures mandated. Once countries began to reopen, this too determined how they performed. Countries with phased, controlled, measured opening did better. Authoritarian approaches as adopted by China — not possible in democracies — also managed to control the virus better.

So, are we out of the woods in india now?

It depends. The pandemic is a dynamic between the pathogen’s ability to infect and kill and the population’s resilience to get infected. If the latter is high, the infections and deaths are lower. This is where the enigma of India lies when trying to figure out why the numbers are dropping. Yes, actions by the authorities and public health measures did play a part, however other factors have also mattered in this “pathogen-host” dynamic.

First, India has a younger population and is hence more resilient, unlike countries with an older population. Second and this is a generalisation, India seems to have a stronger innate immunity since its population is exposed to many pathogens. There exists a stronger immune system to combat a new pathogen. Third, this particular virus has a cousin called the cold coronavirus — which causes some of the regular colds — that has given India’s population some more immunity. Then, there’s interesting evidence to show that countries that have strong penetration of the BCG vaccine had lower mortality. Climate — warmer and more humid — may have helped.

But the moment the virus changes, the dynamics can shift quite rapidly. So, I think we are not yet out of the woods. If India sees the South African or Brazilian type of mutations, our numbers will rise rapidly, as has happened in those countries. But if we get large numbers vaccinated, we could triumph over the virus and its mutations. Picking up mutations before a spike in numbers is very critical. This is where I worry for India.

I would strongly like to push for genomics. It is the future of medicine in areas like oncology, autoimmune diseases, neurodegenerative diseases and many others. We need to understand our own ethnic genome better so we can develop treatments and drugs optimised to work best with our diverse ethnic groups, not just apply treatments and drug dosing developed for other ethnic groups.