The government hopes that it will increase to 10 days by the end of the week, and 12 days by the first week of May. The government hopes that it will increase to 10 days by the end of the week, and 12 days by the first week of May.

Even as the Union government is looking at various options for “gradual” lifting of the lockdown post-May 3 and hopes that the doubling time of COVID-19 cases will increase to 12 days by then, sources said it is preparing for a second wave in late May or early June, as restrictions are eased.

On Monday, the Health Ministry said the doubling time — an epidemiological metric of how long an infectious disease takes for the number of cases to double — is 7.5 days, up from the 3.4 days before the lockdown. The government hopes that it will increase to 10 days by the end of the week, and 12 days by the first week of May.

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“At our worst, our doubling time was 3.4 days. We are expecting to touch 12 by April-end or early May, but after that, as we gradually start to open up — the lockdown will definitely not be lifted in one go — there will be a gradual increase (in cases). We are looking at a second peak in late May or early June, but now that awareness levels are high and people are getting used to the idea of social distancing, masks etc, we do not anticipate the doubling time dipping to below 5 days at that point,” said a source.

It is likely that the cases will be concentrated around urban and peri-urban areas, where COVID-19 management will be less challenging than in rural areas.

“However as Mumbai, Indore and Chandigarh have shown us, there are so many unforeseen developments in this battle. Sometimes cities that are expected to do well explode, while at other times cities where you expect a problem to happen somehow manage to hold it together,” said the source.

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There is a sense that area-specific lockdowns and relaxations will have to be the norm, depending on the rise and fall in cases, till September at least.

While the government hopes that the second wave will not touch the March high of 3.4 days doubling time, it will still mean a rise in fresh cases.

However, the medical infrastructure — including hospital beds, PPEs and ventilators — is expected to be better prepared in June than it was in March.

April 20 easing of lockdown restrictions: Here’s the list of what opens and what does not

While there is no clarity yet on the criteria for lifting the lockdown post-May 3, the Health Ministry’s classification of districts into red, orange and green is being carefully watched.

In her letter to the states last week, Union Health Secretary Preeti Sudan had said: “Containment operation would be deemed over when there is no case reported in 28 days from an area after the last case tests negative. Hotspots (designated red zones) will be assumed to be undertaking effective containment activities if no case is reported in the next 14 days (designated orange zones), and will be deemed successful in containment if no case is reported for 28 days (designated green zones).”

The red zones are areas which account for 80% of the cases in the country, or 80% of the cases in a state, or where the doubling time is less than four days.

Currently, there are 321 districts with no cases; 77 have not reported cases for 7 days; 62 for 14 days; 17 for 21 days; and 3 districts (Mahe, Kodagu and Pauri Garhwal) have not reported cases for 28 days.

However, officials pointed out that the classification of districts into red, orange and green zones is quite fragile, as a single case may send a district back into the red zone.

The government is also looking at international models, such as South Korea and China, to get an idea of how to structure life after lockdown.

“The broad criteria for lifting restrictions is clear — where the epidemic has been suppressed, there is a certain level of preparedness on the part of the district administration, and people have adjusted to the new normal of social distancing and other behaviour changes,” said an official.

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