The TLDR: India’s Covid numbers continue to confound the experts. First, they fell for no apparent reason—and now they are surging just as inexplicably. What is going on here? Here’s a short explainer that sums up where we are and what we know.

First, the numbers: We added 81,456 new cases on Thursday—the highest in six months—and there were 468 deaths, the highest in 117 days. It took us just 4 days to add 100,000 cases. Delhi’s daily numbers spiked by 53% and hit 2,790. Maharashtra tops the charts as expected with 43,183 cases—which account for 53% of the nationwide count. Punjab (3,187) and Chattisgarh (4,617) hit an all time high in the number of daily cases. Karnataka added 4,234 cases—making it the third state (after Maharashtra and Kerala) to hit the 1 million mark.

Mapping the second wave 

Experts are warning of a 'severe, intensive' new wave that will likely peak in May. Hospitals are already overwhelmed. A Wardha doctor says:

"The virus seems to have become more transmissible in the second wave. We are admitting entire families who are infected. We are also seeing a lot of young people, aged below 40, getting sick."

And the numbers are growing fast, according to mathematical models: “the last time infections grew this rapidly was last May. But the daily caseload numbered a few thousand then—not 55,000, the current average.”

Where’s the peak? Most agree that the country will hit its peak in May—but some states like Maharashtra may already be there. But more important is how high will it go? According to some experts, if cases continue to rise at current speeds, then the national peak will be considerably higher than the first one. 

A very mysterious wave

Everyone is worried about the second wave, but most don’t have a good explanation for the strange anomalies in the data:

One: Why did the cases suddenly start to peter out after a peak in September? Earlier this year, many theories were put forward: herd immunity, weaker variant, Indians’ natural resistance due to poor sanitation, younger population etc. (explained in detail here). So what changed in February?

Two: Yes, people are out in great numbers, but social distancing has been a joke for a great many months. It doesn’t explain the peak in September or the sudden decline after—right when the restrictions were almost absent.

Three: A number of serological surveys indicated that far greater numbers of people were infected in the big cities—especially the poorer parts (explained here). While none of them suggested that we achieved herd immunity, they did indicate that great parts of the local population had antibodies. So why are the numbers surging the most in these very cities—especially Mumbai? Or now, Delhi?

Solving the big mystery

There are three possible answers for this second wave.

One: Human behaviour. One school of experts say:

“After being cooped up in their homes for nearly a year, many Indians have begun congregating at crowded weddings and family functions without taking precautions. ‘It is behavioural fatigue. This has led to a dangerous form of fatalism, and the propensity to take risks,’ Dr Kalantri says.”

And the government’s own behaviour—campaigning in full swing in front of packed election rallies—isn’t inspiring caution.

Two: A new, more infectious but less lethal variant. That’s the conclusion of a Times of India analysis that shows a big uptick in cases, but a falling case fatality rate—i.e. percentage of infections that result in death. The CFR has dropped by 75% for Maharashtra, 41% for Punjab, 83% for Gujarat, and 72% for Madhya Pradesh. 

The most vulnerable this time around are those who were left uninfected by the first wave. This includes the young: 

“Children and young adults are mostly uninfected so far and therefore are at high risk of contracting the infection. The schools and colleges are functioning in most States resulting in higher risk of transmission in closed settings. Young adults have resumed working from office and are again at higher risk in closed spaces.’’

This would explain the low number of deaths since young people are far less likely to develop severe symptoms. Also at risk: those living in more remote rural and tribal areas—who also do not have the healthcare resources to deal with a big surge.

Three: Reinfections. There’s always the possibility that the new variant is also able to escape the antibodies produced by a first infection. This is the simplest and most obvious explanation for the big surge in states that have already experienced a significant first wave. Example: Maharashtra. A recent government study revealed that 4.5% of the cases between January and October 2020 were reinfections. One of the authors says the percentage is likely to be far higher now—but we lack the infrastructure to track reinfections that require genome sequencing. 

Point to note: the government continues to deny any role of the variant in triggering the wave.

So what do we do now? 

The obvious answer is vaccinations, administered as quickly as possible—and targeted at the worst affected locations. That’s why the government has urged states to vaccinate everyone over the age of 45 in the districts with the highest caseloads. And it has changed course, veering away from vaccine diplomacy, focusing instead on the home front. Serum Institute has now delayed delivery of 90 million doses to the UN Covax program—which provides vaccines to poorer countries. 

Point to note: It may be too late to quell this wave, however:

“But the current pace of vaccination—more than 50 million doses administered in a little over two months in a country with a population of over 1.3 billion—is 'going to have little effect on slowing spread of the virus in a month or two,’ says Dr Banaji.”

Others say that India missed a huge opportunity by not being more proactive in its rollout:

“I do feel frustrated that India did not roll out the vaccination drive more aggressively while the curve was in its valley… It is much easier to roll out vaccination when the infection is not so high. Now the healthcare capacity is stretched between vaccination and Covid care."

The bottomline: Social distancing works against every variant, and can end any kind of wave. This isn’t rocket science.

Reading list

BBC News has a very good overview of the second wave. Times of India offers a data analysis of the second wave to make the case for a new variant. Indian Express has a detailed analysis of Covid data—and lays out the anomalies in the data. The Hindu has more on who is most vulnerable to infection.