ARI SHAPIRO, HOST:
The second wave of COVID-19 in India has not only been massive, it's also been swift. Back in February, cases were dropping across the country. And only a few months later, India is now reporting nearly 400,000 cases a day. As NPR's Michaeleen Doucleff reports, scientists are just starting to find clues to why the surge exploded so quickly there.
MICHAELEEN DOUCLEFF, BYLINE: When the pandemic first began, Bhramar Mukherjee went to work. She's a statistician at the University of Michigan, and she built a computer app to track COVID-19 throughout India. She monitors the app like a hawk.
BHRAMAR MUKHERJEE: My parents and my students even laugh at me, that every morning I sit down with my cup of coffee and look at the app to just see a metrics. Like, how are the each of the states looking like?
DOUCLEFF: Mukherjee's app is powerful. It makes predictions about what the virus will do in the future weeks, even months from now, so it can catch a surge before it happens.
MUKHERJEE: That's the advantage of having real-time tracker of not just case counts, but real, relative changes sensitive to an uptick.
DOUCLEFF: Back in the winter, the situation looked good in India. COVID cases were low and falling. Then in mid-February, Mukherjee's app picked up a signal. The virus was behaving differently. She predicted a big wave coming.
MUKHERJEE: At first, it was noted in three states. And I tweeted so that we can vaccinate like crazy before the wave actually hits us.
DOUCLEFF: But, she says, policymakers didn't act. Instead, in March and April, several regional governments allowed very large gatherings. The surge not only happened, it was even worse than she predicted.
MUKHERJEE: I said that 300,000 cases and 2,000 deaths are going to come, and nobody believed me at that time. We are so much past that, right?
DOUCLEFF: Things like election rallies and relaxing precautions have clearly played a role. But what Mukherjee detected early on, another scientist says that was something different. A new variant has emerged in India.
TOM WENSELEERS: It has a very big transmission advantage or growth advantage.
DOUCLEFF: That's Tom Wenseleers. He's a biostatistician at the University of Leuven in Belgium. Back in the fall, he was one of the first scientists to recognize that a variant in the U.K. called B.1.1.7 was more contagious than other versions of the virus.
WENSELEERS: It really started worrying people because it increased to such a high proportion in such a short time.
DOUCLEFF: At first, no one believed him. But follow-up studies showed that Wenseleers was correct. B.1.1.7 is 50% more transmissible. Now he sees signs that the new variant in India may transmit even faster. Using computer models, he estimated how quickly this variant is spreading compared to other mutants. He did this analysis in three states in India and in the U.K. In all four cases, the new variant in India has the advantage.
WENSELEERS: If you take all these sort of pieces of evidence together, I'm fairly confident that there is a growth advantage and that it has to do something with the current epidemic in India.
DOUCLEFF: Of course, there are caveats here. The analysis is preliminary. And in the past few weeks, India has published very little information on the variants there. Karthik Gangavarapu is a computational biologist at Scripps Research Institute. He says that for these reasons, he's not convinced yet that the new variant in India is the fastest spreading mutant out there.
KARTHIK GANGAVARAPU: To be clear, I'm not saying it's not. I'm just saying that, you know, there's a burden of proof you need to establish before you say that it's more transmissible.
DOUCLEFF: Still, though, he says, there's no question the variant in India is worrisome and something the whole world needs to try and stop together. Michaeleen Doucleff, NPR News.
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