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Modelling, testing, sero survey, vaccine — 4 lessons India learnt from 4 months of Covid

Each month since the Covid lockdown began in March has brought about a change in the priorities and focus of India’s disease control strategy.

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New Delhi: It has been over four months since India was gripped by the Covid-19 pandemic — PM Narendra Modi’s announcement of a nationwide lockdown on 24 March, when the total number of cases in the country was just 538, was the first signal that a protracted battle had begun.

The journey seems nowhere near the end, with the number of cases and deaths continuing on an upward trajectory — from 1,637 cases on 1 April to 21,53,010 on 9 August. But each of the last four months has opened up new vistas in India’s understanding of the disease, which the world had never seen before.

Here in an in-depth look at how India’s priorities and the focus of its disease control strategy changed, and the lessons it learnt during the last four months.

April — modelling is fallible

By April, it had been three months since the World Health Organization (WHO) sent out an alert about a global pandemic. But Covid-19 was still too new and the death numbers abroad too shocking.

Indians probably realised the seriousness of the challenge for the first time when PM Modi appealed to the public to shun Holi celebrations on 10 March. The next 15 days, at the end of which the unprecedented lockdown brought the country to a grinding halt, seemed like a lifetime.

By the time April rolled around, the country was still reeling under the enormity of the predictions being made about the proportions of the pandemic in India.

Economist and epidemiologist Ramanan Laxminarayan, director of the Center for Disease Dynamics, Economics & Policy in Washington and a senior research scholar at Princeton, wrote in a piece in The New York Times on 27 March, stating that initial estimates showed that 300 million to 500 million Indians were likely to be infected with the novel coronavirus by the end of July.

“Most of the cases would be without symptoms or with mild infections, but about a tenth — 30 million to 50 million — would most likely be severe,” he wrote.

The predictions were immediately rejected by the government, and look far-fetched even now. But clearly, the government was undertaking modelling exercises of its own. On 26 April, it shared a projection with states that predicted that by 15 August, India would have 2.74 crore cases.

That prediction, too, was off the mark. In hindsight, the message that April brought was the unreliability of modelling exercises.

A senior technocrat who didn’t wish to be named told ThePrint: “Models can tell you what you want them to. For the same questions, modelling projections can give such drastically different figures that it is difficult to take a decision based on those.”

Also read: India’s response to coronavirus can’t be based on existing epidemiological models

May — test, test, test

Early on, India had junked the WHO’s advice to “test, test test” to tackle the pandemic, opting instead to go with Indian Council of Medical Research director general Dr Balram Bhargava’s prescription to “isolate, isolate, isolate”, which he gave during a press conference in March.

But by May, there was increased emphasis on testing, and the ‘empowered group 2’, led by then-environment secretary C.K. Mishra, made this a primary focus.

On 1 May, about 74,600 tests were done in around 400 laboratories around the country, of which about 100-odd were private laboratories. The total number of tests stood at 9,76,363.

By 21 May, there were 555 testing labs, of which 391 were in the government sector and 164 in the private sector. Ten days later, the total number of tests stood at 38,37,207.

Having encountered some initial supply issues, India pulled out all stops, roped in its TB testing arsenal of CBNAAT and TrueNat machines, and achieved a great amount of self-sufficiency in testing kits and reagents. On 20 May, about 75 per cent of the RNA extraction kits, viral transport medium kits and RT-PCR were being ordered from domestic manufacturers. Fourteen of the 28 companies whose RT-PCR kits had been approved by ICMR were Indian.

Drawing on those lessons, India is now planning to step up testing to 10 lakh a day. On 8 August, the number crossed 7 lakh — the highest single-day figure so far.

Former environment secretary Mishra said: “In March, the disease was contained in just a few pockets; we didn’t feel the need to test elsewhere. Today, the disease is spreading, but you also have way more testing facilities. Then, we didn’t have a supporting test; now, we have antigen tests. A lot has changed since March.”

However, he added: “But if we go by the WHO standards, even now, we are not testing enough. Our testing is strategic and focussed.”

Also read: Effective contact-tracing, testing must if schools are to be reopened, Lancet studies say

June — startling results of sero surveillance

India’s early misadventure with Chinese antibody testing kits in April had put a stop to the predilection for rapid tests, at least in the short term. But June brought learnings about the importance of antibody tests in understanding both the width and the depth of the pandemic.

ICMR’s survey of 0.73 per cent of those tested in 65 districts did not make much of a dent. But when a survey was conducted in the 11 districts of Delhi, soon after Union Home Minister Amit Shah stepped in to deal with Delhi’s rapidly increasing Covid infections, it threw up startling results.

The survey was undertaken in late June and the results came out only about a month later. But the knowledge that around 46 lakh people in Delhi had been infected by 20 June exposed how much of the infection a restrictive testing strategy had ended up missing. This was despite a massive rise in daily testing numbers.

The Delhi survey underscored the importance of better knowledge of the spread of an infection in the population, in order to be able to control it. There are now more sero surveys being undertaken in Delhi, Andhra Pradesh, Maharashtra and several other states.

Also read: Experts back Delhi’s focus on antigen tests for Covid, call it best way to utilise resources

July — push for vaccines

ICMR DG Bhargava set the tone for a fresh discourse when, in a startling letter on 2 July, he told principal investigators of a Covid-19 vaccine manufactured by Bharat Biotech, which was in the pre-clinical stage, that trials needed to be completed by 15 August. Much water has flown under the bridge since then, with the ICMR explaining that no compromise was intended on scientific rigour, but the spotlight has since remained firmly on vaccines.

Zydus Cadila has started its own Phase I and II trials, while the Serum Institute of India has got the nod for trying out the Oxford University vaccine in India.

The world over, there are 141 vaccine candidates in pre-clinical phases and 26 in different phases of clinical trials, including the three regarded as the most promising — the Moderna mRNA vaccine, the Oxford vaccine and a vaccine developed by China currently being tested on personnel of its People’s Liberation Army.

Dr Bhargava said in a briefing on 4 August: “The need for a vaccine is great and urgent. But there is a dilemma. The pandemic is progressing rapidly. Developing a vaccine takes time not just from the science aspect but also social, cultural and regulatory aspects.

“We have three vaccines in trials. The first is the Bharat Biotech vaccine that completed Phase I study in 11 sites and started on Phase II. For the DNA vaccine of Zydus, India has completed Phase I and moved to Phase II in 11 sites. The third vaccine (that) got approval yesterday is the recombinant Oxford vaccine that was approved for Phase II and III trials that is starting in 17 sites.”

Also read: Why coronavirus vaccine confronts humanity with the pandemic’s toughest moral test


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