The country may see a worsening of its outbreak as soon as this month, with the next wave peaking in the best-case scenario with less than 100,000 infections a day, or nearly 150,000 in the worst scenario, according to estimates by researchers led by Mathukumalli Vidyasagar and Manindra Agrawal at Indian Institute of Technology in Hyderabad and Kanpur respectively.

States with high Covid rates, such as Kerala and Maharashtra, could “skew the picture,” Vidyasagar told Bloomberg in an email.

The next wave is likely to be far smaller than the second wave that peaked at a record 400,000-plus daily cases on May 7 and declined sharply thereafter. But the forecast still underscores the need for India to accelerate its vaccination campaign, deploy surveillance methods to catch emerging hotspots and stay vigilant through genome sequencing given the potential for new variants to emerge.

The delta strain now causing renewed outbreaks across the world was first identified in India last October.

Model created by Vidayasagar’s team.

Experts are concerned about complacency setting in as people resume social and business activity in the face of waning infections. India’s first outbreak last year ebbed with limited damage, leading to a quick resumption of local travel and large-scale festivals that drove the emergence of a devastating second wave in March. With hospitals and crematoriums overwhelmed, researchers estimate that as many as 5 million people may have been killed in that outbreak. The government estimates of total Covid-related fatalities so far is 424,773.

But that last wave also lead to high levels of natural immunity in the country’s nearly 1.4 billion people -- a factor that could blunt the impact of the next surge. A national antibody survey by the Indian Council of Medical Research study last month found that two-thirds of Indians above the age of six had been exposed to the coronavirus.

Next Hotspot

Five months after the last wave started, daily infections in India have plateaued at around the 40,000 daily mark. For the past five days, roughly half the new cases are coming from the southern state of Kerala, making it potentially the next hotspot.

The higher infection rates in Kerala are likely due to the state conducting more testing than other places, where cases may be under reported due to limited detection efforts.

Daily cases have grown persistently through July in Kerala and a few smaller north-eastern states, said Paul Kattuman, professor in the Judge Business School at the University of Cambridge, which has developed a Covid-19 tracker for India.

But a few other Indian states also saw “short-lived flare-ups in July which abated relatively quickly,” putting the country overall in “a steady state” for now, he said.