No, Yogi Adityanath, migrant workers do not have better immunity

During a webinar on 24 May, Uttar Pradesh chief minister Yogi Adityanath claimed that migrant workers from the state found infected by covid-19 showed much faster recovery rates than “normal persons".

“We know that migrant labourers who come back are likely to be infected [with Covid-19]," he said. “But they work hard and sweat, and naturally they have the capacity to fight the virus. If a normal person gets infected, then they are taking 14 to 20 days to recover. Migrant labourers are testing negative on the sixth or seventh day. This is our strength…"

Over 23 lakh migrant labourers are estimated to have returned to Uttar Pradesh since the nationwide lockdown was imposed on 24 March. As of 27 May, Uttar Pradesh has tested 2.4 lakh people for covid-19, found 6,991 positive and seen 3,991 recover. There’s no data in public domain showing how many of these are migrant workers or how long it took them to recover.

What is available, though, are harrowing accounts of lakhs of migrant workers’ journeys back home: packed away in buses, trucks, tempos and trains, with little regard for health, hygiene or social distancing.

Those carted off by special Shramik Express trains have reported fights for food and water at halting stations. On 27 May, a video emerged of a toddler tugging at his dead mother lying on a train platform in Muzaffarpur, Uttar Pradesh. The woman, a migrant worker, had reportedly died of heat, exhaustion and starvation while returning from Surat. Even the Supreme Court, in a reversal from its earlier stance, stepped in on 26 May and asked the government to report the “steps taken to redeem the miseries of migrant labourers".

“It seems to me an almost deliberate distraction from what should be the real focus of both society and the government," saya Dr Satyajit Rath, immunologist with the Indian Institute of Science Education and Research (IISER), Pune. “Instead of dealing with the social and economic hardships that the poor are subjected to; instead of building up hospital capacity and increasing contact tracing, why are we even discussing if one category of people clears [covid-19 tests] on day 7 and another on day 14?"

To make sense of the UP CM’s claims, Mint spoke to four experts – academics and scientists. No study on migrant labourers’ immunity has been conducted so far, they said. And even if some were displaying faster recovery rates, it’s too early to attribute it to their lifestyle, one of “hard work and sweat".

Lacks scientific basis

At the outset, Dr Sampa Mitra, epidemiologist at the All India Institute of Hygiene and Public Health, Kolkata, said that there wasn’t any scientific basis to find that the death-rate among migrant labour was comparatively lower than others. However, a persuasive case can be made for the same.

“Hard labour for limited hours can do people good. Strong body means better immunity," said Dr Sampa Mitra. “A lot of migrant labourers receive a regular salary, so their nutrition levels aren’t too bad either."

A number of labourers, she added, are known to live in small, crowded housing clusters in cities. The probability of covid-19 transmission in such areas is high. “Due to moderately good nutrition and immunity, infections can happen but they might remain asymptomatic," she said. “But before concluding that, we must ensure that the [infected] migrant labourers have lesser death rates than others."

Dr GP Singh, faculty in Lucknow’s King George Medical University and former president of the city’s Indian Medical Association (IMA), said that the low covid-19 death rate in India can also suggest that Indians – not just the working classes – have a better immunity than their counterparts in the West.

“We are already so exposed to bacteria and viruses and [hostile] environmental factors, our immunity is different from those in the West," he said. Indians’ dietary habits, he added, can also add to the increased immunity. “We use a lot of spices, onion, garlic and ginger [in our food], which is not as common in the West... Our death rate due to covid19 is far lower than the western countries. There must be something to make that." Data from Johns Hopkins University suggests that India’s death rate is around 3% compared to around 6% in the US.

However, he too clarified that there’s no scientific basis to back up either of the two theories.

As for migrants, Dr Singh said that Adityanath’s claim was likely a “political statement". “But since my chief minister is saying that, I can’t contradict also. You see, I have to live in UP only."

Distraction from real issues

Dr Singh’s speculations about Indians’ superior immunity are similar to Adityanath’s own views.

In late April, the UP CM said that Indians displayed a stronger immunity than those in the US and Europe when dealing with covid-19. “In UP, about 70-75% of 1,900 cases are asymptomatic which means their immunity is strong," he said. These numbers are hardly remarkable though: as per a World Health Organization’s situation report on 6 March, 80% of the documented covid-19 cases across the world were asymptomatic.

“It’s not my claim that nutrition and energy has nothing to do with immune system," Dr Satyajit Rath from IISER said. “If you do physical exercise, immunological measurements show improvements in everything, including mood, memory, blood pressure. But I see no reason to extrapolate such small quantitative measurements into a model of how migrant labour should respond."

The main question, he adds, is how one distinguishes a “migrant labour" from “normal person". “If you want to do comparison, every other confounding factor: diet, age, sex, socio-economic status should be comparable between controlled test group. Only then can you come up with such evidence."

It has now been a little over 4 months since the cases of covid-19 surfaced in India. As on 27 May, India had detected nearly 1.6 lakh covid-19 cases, over half of which were active. Even as the health ministry denies it, a lot of experts claim that community transmission has begun in India. With research still going on into the nature of the virus, its transmission and susceptibility to the populace, it might be too early to jump to conclusions on the profiles of certain demographics and its contribution to their recovery rates.

“Scientific terms cannot be used loosely," said Dr. Sanjoy Kumar Sadhukhan, head of the All India Institute of Hygiene and Public Health. “It requires investigation and study. If it is studied for 2-3 years, you might find out [if migrant workers recover faster]. Politicians can say anything. So it’s up to them to explain, not me."

Mint’s email to the Uttar Pradesh Directorate of Medical & Health Services, requesting for data, study and the reasoning behind Adityanath’s claim, went unanswered.