Lockdown is just one aspect to contain the spread of COVID-19, enhanced testing, isolation of infected individuals, monitoring of development of herd immunity, a phased withdrawal of the lockdown should all be part of the strategy to fight the virus feels Partho Sarothi Ray, associate professor of biological sciences at the Indian Institute of Science Education and Research, Kolkata. Prof. Ray spoke to Shiv Sahay Singh of The Hindu on the outbreak of COVID-19 and measures taken to contain the spread.
What do we know about COVID-19 and how far do you think we are to finding a cure?
Though it is a novel virus, virologists have been familiar with this group called coronavirus. This group had caused outbreak of SARS in 2002 and MERS in 2009. It is less lethal than SARS but significantly higher than influenza virus. Very lethal viruses, such as SARS, Ebola, cause limited infections because they kill the people they infect and they do not get a chance to spread rapidly. However, COVID-19 is highly infective; nearly twice that of influenza virus. That is why it is spreading rapidly throughout the world. Most of the people dying of the infection are the elderly, people with comorbidities and those whose immune system is suppressed.
Our record of finding cures to viral disease is not great. It is very difficult to find specific antiviral drugs targeted to specific virus. Finding an antiviral to this virus is not going to happen easily. Currently various antiviral drugs targeted for other virus like influenza are being tried out to treat COVID-19. One of the reasons is that this virus changes rapidly and gives rise to variants. Already, we know that there are multiple variants and a vaccine against one variant may not be effective against other.
As a virologist what do you think, after the lockdown will the spread of the disease be contained?
If you just do a mathematical modelling of how long it will take to stop the epidemic by doing just a lockdown, I think it will be required till June or may be as far as September. In a lockdown you have infected asymptomatic individuals who are staying in their homes and infecting people around them. After the lockdown is lifted they will go out and infect more susceptible people, so there will be resurgence. The question is whether is it feasible for us to keep extending the lockdown. We have seen the pain that the lockdown has brought, especially to the poor.
The only way to stop this is to increase testing to such a level that we are able to identify and isolate these asymptomatic infected individuals. This should be the aim of the lockdown period.
So the more the testing the better we are prepared to deal with the situation?
We have seen countries like Germany, Italy going up to 13,000 14,000 tests per million. In the U.S. the number is 7,000 per million. I really don’t know if it is possible to achieve such numbers in India. We are saying that there is a need to increase testing in places where you are seeing infections. There is an urgent need to test asymptomatic people, people under quarantine or contacts of infected people. Because of high infectivity of the virus the insistence on testing comes into play. If we are able to test and isolate infected persons then we should be able break the chain of transmission.
There are concerns about the cost of the tests which comes to ₹4,500 per test. Can the price of test be reduced?
ICMR has approved a specific test protocol for COVID-19 which is based on some kits. These kits are nearly all imported and therefore there is dependency on them. Even using the kits, the pricing should be substantially less. In fact, a cost estimate for a test comes to around ₹700. If we also explore alternative methods which are regularly used in the labs the tests can be carried out at a cheaper cost. It can be done by reagents which are cheaper. We do not know whether these have been explored substantially. What we are suggesting is alternative testing should be encouraged and the dependence on the imported kits should be reduced. In that way both the price of testing can be made more realistic and more testing labs can be engaged.
There are talks about herd immunity? What are your views on it?
The way such viral transmission is stopped is by development of herd immunity. Herd immunity is when a large section of the population develops immunity against the virus and thereby stops its further spread. Herd immunity can only develop if people start developing antibodies against the virus. For that certain level of interaction has to be there among the population.
So lockdown cannot be the only strategy?
Lockdown should be part of a broad well planned comprehensive strategy. Lockdown is just one aspect of the strategy. Other measures like enhanced testing, effective isolation of infected individuals, monitoring of development of herd immunityshould go hand in hand with lockdown as part of comprehensive strategy to fight the COVID-19 outbreak.
