The severity of India’s second COVID-19 wave took the world by surprise. Cases skyrocketed, at one point accounting for roughly half of the total infections reported globally. Then, almost as quickly, the numbers plunged.
MedPage Today spoke with experts on the ground in India and in the U.S. to better understand the dynamics of India’s COVID curve, and to find out what lessons other countries can learn from its experience.
All of the physicians and public health experts who responded to our inquiries agreed that one of the primary reasons the virus dissipated so quickly after the second wave was that it simply had nowhere left to go.
Not a Wave but a ‘Sharp Spike’
The “virus inferno” is how Bhramar Mukherjee, PhD, of the University of Michigan School of Public Health in Ann Arbor, refers to India’s second wave, which hit before the country had a chance to fully roll out vaccination.
Seroprevalence surveys at the end of June found that roughly 70% of the Indian population had SARS-CoV-2 antibodies, said Mukherjee, which can only mean that those antibodies were the result of past infection. At that time, India had vaccinated only about 2% of its population. In the U.S., seroprevalence rates were closer to about one in three Americans prior to vaccination, she noted.
During the second wave, the country witnessed a “very sharp spike and fall,” which, as seen in other outbreaks, often occurs after the virus returns with a mutation that is more transmissible, in this case, of course, being the Delta variant, she continued.
At the same time, human behavior grew more lax, said Mukherjee.
Gagandeep Kang, MD, PhD, of the Wellcome Trust Research Laboratory at the Christian Medical College in Vellore, India, and an adjunct professor at Tufts University in Massachusetts, agreed, noting that by January and February of this year, “you could see that the masks were coming off or were inappropriately used.”
When Delta arrived, “hardly any household was spared,” said Arvinder Singh Soin, MD, of the Institute of Liver Transplantation and Regenerative Medicine in Medanta, India, in an email.
At this point, people weren’t as willing to stay home. Some were in denial and others simply had pandemic fatigue, Mukherjee said.
Kang recalled the “tens of thousands of people” at election rallies and the millions who took part in festivals and pilgrimages across the country, who then brought the virus back to their communities.
“So … the virus is coming back with [a] vengeance and the human beings are letting their guards down. [The] juxtaposition of these two forces often leads to this huge spike that we see … and I think that’s exactly what happened,” Mukherjee noted.
Once people “exhausted” their networks — meaning the infected people had exposed every person they could among friends, family, and colleagues — then cases began to fall, Kang explained.
By then the “sheer devastation,” the fact that so many people lost loved ones, hit a nerve, Mukherjee said. “I think the proximity to death really scared them.”
How long that fear will last is unclear, she added, noting that one of the biggest Indian festivals, Diwali, is set for next week.
There are other uncertainties as well. While much of the country has protection against severe disease due to infection or vaccination, it’s not clear when that protection will wane or by how much, Kang noted.
Apples to Oranges
There are other factors in play when looking at the impact of COVID in India. For instance, 40% of India’s population is under age 18, and disease is usually milder in that younger age group, pointed out Mukherjee. One needs to know “if you’re comparing apples to apples or apples to oranges.”
India’s first wave mostly impacted the poorer urban slums, not higher socioeconomic groups, explained Manoj Mohanan, PhD, of Duke University Sanford School of Public Policy in Durham, North Carolina.
During this first wave, the number of people dying in India was lower, largely due to fewer elderly people living in slums, he noted. The second wave hit those with more socioeconomic stability, and “that’s when … you started to see the number of deaths going up.”
Researchers have also theorized that people in lower-income countries may have stronger immune systems as a result of their increased exposures to an array of diseases and infections, suggesting that this immunity has helped to keep COVID at bay.
While cross immunity does happen, there hasn’t been any “hard data” to support this theory, which is “somewhere between conjecture and wishful thinking,” said Soin.
Lessons Learned
If India has learned nothing else from the pandemic, the importance of syndromic surveillance has been made crystal clear, according to Kang. “Because if you understand what you’re dealing with, then it becomes much easier to develop a strategy.”
She also noted the importance of developing pandemic protocols. Southern states had lower mortality rates among similar patients in Northern states because the South was more prepared, she said.
Early in the pandemic, even asymptomatic patients were brought to hospitals, but by the second wave, homecare protocols allowed symptomatic patients to be managed at home and to receive “oxygen concentrators,” Kang noted.
Another possible mistake was enacting quarantines in India’s slums, because it meant packing a lot of people into a confined space, Mukherjee pointed out. While effective in other places, “you really have to think about what works for India.”
The decision to restrict grocery stores’ hours was also flawed, because it led to crowding. What officials should have done was keep the same hours, but restrict the number of customers, she said.
Second to vaccines, distributing free masks is probably the “best intervention” the country can invest in, she added, noting her strong support for mask mandates.
One surprise was the number of volunteers who stepped up, Kang said. These young people were gathering data from media and government reports, identifying where beds and oxygen cylinders were available, and providing food to people who were quarantined. “The fact that so many young people were so altruistic gives me hope,” she said.
A Third Wave
Despite “hysteria” over a possible surge in July and August, “our models actually never projected the third wave,” Mukherjee said; however, just because a “huge, towering wave” isn’t expected in the next 4 to 6 weeks doesn’t mean that people shouldn’t remain vigilant.
“Unless we’re careful in the festival season and get fully vaccinated, we could be staring at a third wave soon,” Soin said, noting that uptake of second doses of the vaccine has been lagging.
He also emphasized his support for mandatory vaccination certificates for those on welfare, for domestic travel, in public spaces, and at work.
Lancelot Pinto, MD, of P.D. Hinduja National Hospital and Medical Research Centre in Mumbai, said that there are “naysayers” who don’t think India should invest in preparing for a possible third wave.
But when there’s a disease with this many unknowns, it makes sense to prepare for a worst-case scenario, he told MedPage Today on a phone call. “Nobody had predicted Delta. Right?”
Mathematical modeling has shown that there could potentially be a variant that evades the immunity that vaccines provide. And while some may say that these are “doomsday predictions” that will never happen, “I believe there’s no harm in having a plan ready … if things start escalating,” he added.
Even highly vaccinated communities have outbreaks, Mukherjee warned, pointing to Singapore as one example. What’s needed is a “tiered system” in which if metrics reach a certain threshold, different interventions from a “dial-up, dial-down menu” can be drawn and implemented.
“We have to be cautious for a period of time ’till we see strong evidence that this is over,” she said.
While festivals have been ongoing for the past 3 weeks, Kang said that no uptick in cases has been reported anywhere. “So, not to say that it can’t happen. But, so far, there are no huge indicators that things are going awry.”
Source: MedicalNewsToday.com
