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'Amid widespread community transmission in India, hard choices have to be made'

Sumit Saxena | June 21, 2020 11:42 AM

NEW DELHI: Once there is widespread community transmission, as there is in India now, hard choices need to be made, said Babak Javid professor at the Tsinghua University School of Medicine in Beijing and a consultant in infectious diseases at Cambridge University hospitals.

He added that taking into account the densely packed population in India, the progression of the Covid outbreak has not been as rapid as witnessed in some parts of Europe and the US. How it will progress, is at the moment, hard to predict, said Javid.

Q: India is facing a huge problem of rising infection in containment zones, where movement of people is restricted, especially in urban centres. Is there a methodology to contain the spread of the virus?

A: We have seen that several countries e.g. China, S. Korea and New Zealand have been successful in containing the Covid outbreak. But once there is widespread community transmission, as there is in India now, hard choices need to be made, and I think whatever is decided will have significant and serious consequences. We know that already, services for the diagnosis and treatment of tuberculosis have suffered greatly in India, and deaths from tuberculosis, which already amount to almost half a million a year, are predicted to rise as a result. I do think there is no �one size fits all' in responding to Covid: what may be appropriate and effective in one setting may not be appropriate in another.

Q: Italy has started settling down, from 5, 000 cases a day it has reduced to 200 cases a day, but India and the US, in the number of growth of new cases nearly 8, 000 or more daily, are moving in a different direction. Do you think India and the US would end up as the worst hit countries due to this viral infection?

A: Italy was hit very hard and very quickly, at least in part because it didn't realise that there was widespread transmission in Northern Italy until transmission had progressed a great deal. But cases have fallen dramatically. As you say, the US, Brazil, Russia and India have some of the largest daily increase in cases now. However, at least in the US, we can see regional differences. New York and New Jersey, the two worst hit states have had a dramatic decline in cases, much like Italy. The plateau in new cases is, I think, because the US, being a large country, has many different regional outbreaks, which are progressing along their own trajectories. India, as the world's second most populace country, may also be facing these issues, with Maharashtra the hardest hit region. However, taking into account the densely packed population in India, the progression of the Covid outbreak has not been as rapid as witnessed in some parts of Europe and the US. How it will progress, is at the moment, hard to predict.

Q: WHO recently said the asymptomatic less likely to spread Covid-19. In Indian context, a population of over 130 billion, this may have huge implications on track/trace/isolate measures. Has this statement by WHO gone against the grain in tackling Covid-19 crisis?

A: I believe that following the initial statement, the WHO has clarified that there are still many unknowns with regards to transmission by people who don't have classic Covid symptoms. I would agree with that. We know for sure that people that have mild or atypical symptoms do transmit SARS-CoV-2, and we also know that people are contagious before they develop symptoms (pre-symptomatic transmission). It's less clear if truly asymptomatic individuals (i.e. never develop any symptoms) transmit. Regardless, the proportion of transmission from people with no or very few symptoms is not known with certainty: although it's likely to be substantial.

This does have implications for track/trace/isolate for any country, including India. By definition, asymptomatic individuals can only be identified by screening or contact tracing. To interrupt transmission, it's important that cases are identified quickly before they and their contacts have had a chance to transmit further.

Q: Many experts, especially in Italy which was worst-hit by Covid-19, say that it is not possible to develop a vaccine for Covid-19 soon, as the RNA virus changes very quickly and this makes it difficult to create a good vaccine. What do you have to say on this?

A: SARS-CoV-2 is an RNA virus � that is, its genetic material is RNA instead of DNA. Generally speaking, copying RNA results in more errors � mutations � than copying DNA, therefore RNA viruses, in general, have a higher mutation rate than DNA viruses. But it should be noted that coronaviruses, because they have a large RNA genome, actually make fewer mistakes in copying their genome, and the observed mutation rate is not very high. Certainly, the observed mutation rate would not preclude generating an effective vaccine. Indeed, influenza is also an RNA virus, with a much, much higher mutation rate and we still are able to make a vaccine, but because of the mutations that influenza undergoes, we need to �update' the vaccine annually. So far, SARS-CoV-2 has not mutated sufficiently to even warrant an annual vaccine schedule � should be able to identify an effective and safe vaccine � although of course that might change eventually.

Q: How soon could we get a vaccine on Covid-19, and in the absence of the vaccine, should we wish for herd immunity to protect us from this deadly viral infection?

A: We have never developed a human vaccine that is effective against coronaviruses: but partly that is because we haven't needed to before. The endemic human coronaviruses cause the common cold, and the other two highly pathogenic coronaviruses, which cause SARS and MERS, which are rare diseases, so there wasn't that impetus. I am pretty confident that we will identify a number of vaccines that are at least moderately effective very soon. But the greater challenges will be to ensure such vaccines are safe, and that they can be mass produced and equitably distributed for everyone in the world.

With regards to herd immunity, I don't think we understand immunity at a population level to SARS-CoV-2 well enough for me to be able to comment on it.

Q: For its 130 billion population, India has nearly 1.2 million doctors and nearly 2 million nurses along with other healthcare professionals, what safeguards should be deployed to protect them and ensure that in fighting Covid-19, the country does not compromise on the safety of the medical professionals.

A: This is an important issue. We know that in many/most countries, doctors and nurses have sadly been infected by SARS-CoV-2. However, it's actually quite difficult to determine where/how they got infected: from patients they were treating, from other patients not suspected to have Covid (and therefore less stringent protection measures used in treating them) but who may have pre/asymptomatic infection, or even from each other, or from their families? More and more healthcare institutions are moving to treating healthcare settings with �universal precautions', i.e. assume any patient or even healthcare worker may be infected, and places that have done so have seen a decline in hospital associated infections: but of course this has major implications for personal protective equipment procurement, particularly in resource-poor settings.

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