The number of coronavirus infections in India crossed 1,300 this morning, with 44 deaths. The spike was attributed mainly to the spread of the virus at a religious congregation in Delhi’s Nizamuddin which was attended by thousands of people.

On March 19, Ramanan Laxminarayan, director of the US-based Centre for Disease Dynamics, warned that in the worst scenario, 60 percent of India’s 1.3 billion population could contract the virus, meaning 700 to 800 million people. A week later, he revised down the estimate to 300 million, saying the situation was a “moving target...changing all the time”.

But what can India expect the pandemic’s impact to be in the long term? Newslaundry spoke with virologists, scientists and economists to find out. Here’s what some of them had to say:

Dr T Jacob John, former head of the Indian Council for Medical Research's Centre for Advanced Research in Virology

“My projection is that we will have mindbogglingly large numbers,” John said, referring to coronavirus cases. “It doesn’t take much imagination to see that in a country of 1.3 billion people, if 10 percent are affected, it’s 130 million. Out of those, adults would be 80 million. It could even be 20 percent (260 million) or 40 percent (520 million), which isn’t outside the realm of reality.”

In the context of Laxminarayan’s estimates, he added: “I have no idea as to what percentage of Indians might get infected, but 50 percent is not way off the mark.”

“Dr Ramanan is well-informed. The projection numbers that he has given are meant to hit the government hard. The government should anticipate every Indian getting infected. No one is, for some reason, protected from getting infected by this virus.”

John predicted that coronavirus will likely infect the “exact” number of people as were affected by the H1N1 flu pandemic of 2009.

According to 2010 data from the Ministry of Health and Family Welfare, the total number of confirmed H1N1 cases in India was 33,783. A paper on the 2015 influenza outbreak in India said in the post-pandemic outbreak after 2010, the country recorded over 62,000 laboratory confirmed cases with 981 deaths.

Commenting on the “lessons learnt” from the 2015 outbreak, the paper said: “Besides making people aware about the ways to minimize the transmission...health authorities also need to focus on better documentation of the outbreak in terms of descriptive epidemiology, clinical details and severity category of cases in order to identify risk factors for adverse outcomes. These data will also be useful in identifying additional high-risk groups, which could be considered for vaccination.”

The World Health Organisation had warned last year that “the world will face another influenza pandemic”, adding, “The only thing we don’t know is when it will hit and how severe it will be. Global defences are only as effective as the weakest link in any country’s health emergency preparedness and response system.”

John said India must realise that “coronavirus is not an influenza virus but everything else about it is exactly like an influenza pandemic”. It would be a “great success”, he said, if India could limit the infection to just about 10 percent of the population.

“If you think you’ll have only 100 million infected or 200 million, that’s not good,” he said. “If you expect more and take greater precautions than necessary for a small number, that would be in our interest. Expect the worst but hope for the best.”

Professor T Sundararaman, former dean of the School of Health Systems, TISS Mumbai

Speaking about R0, the reproduction rate of a virus read as “R nought”, he explained, “The R0 is the likelihood of people who will be infected from one infected person. Basically, it’s how many people an infected person will transmit the infection to.”

The R0 for coronavirus is estimated to be 2.4 to 2.8, or one person will affect 2.4 to 2.8 people. In other words, Sundararaman said, 10 people will infect 24 people.

The R0 depends on four things, he explained. The virulence of the virus which is its ability to penetrate or infect; the number of people available to infect which increases the possibility of transmission; the persistence of the virus in a person which allows it to infect more people if it has more contact; and the susceptibility of the host, meaning the individual’s age and health.

“Talking about India, the R0 is only one part of the story. As more people continue to get infected, recover and then become immune, the virus has to meet non-immune people to prevail,” Sundararaman added. “A point comes when all the people the virus comes in contact with are immune, leading to its decline.”

The ongoing nationwide lockdown, he argued, will slow down the spread of the virus. On the other hand, as long as the virus exists, the process of infection can start all over again.

“It’ll start doubling and building up again. For instance, let’s say we are able to contain the virus by April, and not many are infected or die of it. The process will start again in a while and the next peak might happen in June or July,” he explained. “It’s happening in Japan right now.”

In Japan, a month after it “successfully contained the first outbreak”, the health minister said there was “evidence that Japan was now at a high risk of rampant infection”. Forty seven positive cases were reported on March 26.

“The same thing happened in the 1918 flu. I am not saying it will happen, but it’s one scenario,” Sundararaman said.

Another scenario is that India’s current projection of positive cases is an “optimistic number” because of undertesting. “Once the lockdown is lifted and higher numbers are tested, the actual percentage is shown, which will be more than what is reported,” he said. “Like South Korea, India could shut down a few states which are reporting the virus and contain it there. But again, if you don’t know how far the virus has spread, how will you know when to contain it?”

“If you are asking me for a simple projection, I’m saying we don’t have enough information to make it,” he said, adding that such predictions were dangerous without data. In the best scenario, the outbreak could be postponed by a few months, until proper equipment and action plans are put in place.

But even then, he cautioned, everybody would still get infected.

According to Sundararaman, there’s a possibility that a significant number of people could have the disease and not be aware of it. The number of cases were restricted by the amount of testing that was being done, he said.

In Jharkhand, for example, the numbers are low, but the state has only one testing facility. “It’s hardly accessible to people and, in general, the state is widely spread out,” he said. “I think we should start going by clinical diagnosis, which is not perfect, and get to an understanding of influenza-like illnesses, screen the number or proportion of people having it, and the spike occurring there.”

Jharkhand’s lone testing centre is a viral research diagnostic laboratory at the MGM Medical College and Hospital in Dimna. The state’s health department said it was “making serious efforts” to increase testing facilities.

India has a relatively young population, Sundararaman pointed out, with an average age almost half that of Italy’s. As such, he believes that the mortality rate will be lower and recovery rate higher. The 2011 census found that about a fifth of the country’s population was aged 15 to 24, and it’s expected to rise to 34.33 percent by 2020.

“However, one problem which we could face is shutting down non-corona care in hospitals,” Sundararaman said. “Comorbidity being what it is, if your diabetes is not controlled, or if you have got an acute respiratory disease, then you are far more liable to the virus.”

According to the International Diabetes Foundation, India has about 77 million diabetics, the most of any country except China with 116 million.

For a better understanding of severe to critical coronavirus cases, the professor noted, it was imperative to find the percentage of people suffering from severe acute respiratory illnesses, chronic obstructive pulmonary diseases, including acute exacerbation, and deaths from either.

“Without the virus, we have so many deaths due to chronic obstructive pulmonary diseases with acute exacerbation. So you will not be able to notice an increase in it due to COVID-19 unless either you test for COVID-19,” Sundararaman said. “If it is on too large a scale, that means coronavirus has really become worse in India than in Italy.”

“We are flying blind through one of the worst problems. Unless you have the evidence to guide decisions, you can’t fly,” he added.

Sundararaman said the lockdown will help in temporarily holding down the number of coronavirus cases. The moment it is lifted, it will spread again.

“Slowing it down is very valuable to do, but it is not necessarily going to make a difference,” he said. “This is something like demonetisation. The lockdown is a bold move, but not necessarily a successful one for meeting its objectives.”

Shamika Ravi, former member of the prime minister’s economic and advisory council

Shamika Ravi, director of research at the think tank Brookings India said she is working with a task force to deduce projections of coronavirus in the Indian context. The task force comprises data scientists, epidemiologists and other experts.

Ravi thinks Laxminarayan’s calculations are “a bit simplistic”. “It seems to be a simple 20 percent transmission rate, which you have seen in China. He’s using that to extrapolate what will happen in India,” she said over the phone. “Now, that is not enough. We might be at a very early stage, so maybe all the preventive measures that are being taken means that the transmission rate will perhaps not be the same as what you have seen in China. That is why the model becomes important. This is serious business.”

Ravi said the prime minister’s allocation of Rs 15,000 crore to healthcare workers and infrastructure was based on internal projections worked on by her task force.

Ravi thinks the lockdown is a proactive step by the government. It’s also a necessity, she argued, since the country can’t afford to wait as it doesn’t have the infrastructure required to tackle a subsequent buildup in cases.

“Naturally, the flattening of the curve has already started. Of course, the escalation will still take place, but it will be much less than the escalation you would have seen if we had done nothing about it,” she said.

Ravi said the government should test more and ensure much larger random sampling at the district level. “We want to come up with a better estimate that could give more precision for policy intervention – such as where the lockdown should continue, where it should be lifted, what are the high-risk hotspots, and areas in which life can go back to normal.”

Dr Rajni Kant, scientist and head of research management, policy, planning and coordination, ICMR

The ICMR can’t project the potential numbers of coronavirus cases in coming weeks since this rests on factors such as the successful implementation of intervention strategies, Kant said. The ICMR’s mathematical model on cases in India isn’t for projections, he said, but to determine the impact of symptomatic quarantine on the progression of the epidemic.

On the possibility of severe to critical COVID-19 cases in India due to the prevalence of diabetes, hypertension and heart disease, Kant said compared to the global scenario – where five percent of cases are severe or critical – India has a low number of infected cases with respect to its population. He added that detailed investigation of India’s cases will provide more information.

How is India handling the pandemic so far? Kant said the mitigation strategies currently in place are keeping it in check. These strategies include thermal screening of international passengers at airports, cancellation of visas from affected countries, restriction of international flights, close check on international passengers and their contacts and isolation of those infected, and restriction on domestic movement.

“The current steps taken by the Indian government are based on the situation analysis by a team of experts,” he said. “Requisite steps were taken at the right time and according to the situation.”

Kant added: “If we’re able to flatten the curve, our healthcare system will be able to withstand the current health situation effectively.”