Why Herd Immunity Won’t Save India From COVID-19

Rather than relying on mass infection to build resistance to the coronavirus, the country needs a long-term, data-driven, decentralized approach.

Residents make their way along a road in Amritsar, India, on April 30.
Residents make their way along a road in Amritsar, India, on April 30. Narinder Nanu/AFP/Getty Images

India reported its first case of COVID-19 on Jan. 30. As of May 1, while the country moves through its fifth week of an unprecedented national lockdown, a total of 25,148 cases have been confirmed with 1,152 deaths. While these figures may seem relatively low compared with hot spots in Europe and North America, they may not be capturing the real picture. So far, India has tested only 902,654 samples, which equates to around 694 tests per million people—one of the lowest rates in the world; furthermore, testing figures vary by state.

With 0.55 hospital beds per 1,000 people, only 48,000 ventilators, and a population of 1.3 billion, many observers wonder how India can manage a crisis as severe as the coronavirus.

Pursuing herd immunity has been touted as a possible strategy in poor countries with young populations, such as India. This controversial approach, which was recently discarded by the United Kingdom, relies on a majority of the population (60 percent to 80 percent) gaining immunity or resistance to the virus by becoming infected and then recovering.

While this is a common approach underlying mass vaccination campaigns for diseases like measles—which rely on safe and tested vaccines—trying it with a deadly, new, and untreatable disease is a massive risk. In its cruelest form, it is a version of survival of the fittest.

There are three reasons why herd immunity may not work for India and could also be potentially dangerous—leading to increased hospitalizations that overwhelm the health system and eventually cause a high number of deaths.

First, experts don’t know a lot about COVID-19 immunity, especially how long immunity lasts, what kind of protection it offers, and whether reinfection is possible. These are all questions that researchers around the world, including those at the World Health Organization, are still trying to figure out.

In its cruelest form, pursuing herd immunity without a vaccine is a version of survival of the fittest.

Second, herd immunity is being recommended for India on the assumption that since the country has a large young population (more than 80 percent fall below the age of 44), many of these younger adults will not have a severe reaction to COVID-19.

However, this assumption is problematic as scores of young Indian adults have dangerous underlying conditions and risk factors that could lead to severe complications and death if infected with COVID-19.

Nearly 40 percent of Indian adults aged 45-54 and 22 percent of those aged 20-44 have hypertension; nearly 4 percent of adults aged 15-44 years have reported Type 2 diabetes, along with a high rate of unreported cases; and 2.1 million people are living with HIV, of whom 83 percent are between 15 and 45 years old. Finally, the prevalence of chronic pulmonary disease and asthma among adults was reported as 4.2 and 3 percent, respectively, and nearly a third of adults use tobacco.

With such high rates of comorbidities and risk factors among the young population, letting the virus spread for the sake of an experimental strategy of herd immunity could lead to hundreds of thousands of people being hospitalized and requiring intensive care. Furthermore, seeking herd immunity among younger populations would still require shielding older adults (roughly 50 million Indians are over the age of 65) who are at higher risk.

This raises the question of how to isolate older Indians, many of whom live in multigenerational family homes, which is still the norm—especially in rural parts of the country.

Relying solely on a herd immunity strategy could also be dangerous as it may lower the risk perception among younger populations, affecting their compliance with much-needed social distancing measures.

Third, herd immunity cannot be implemented as a lone strategy. It will still have to be supplemented with ramping up health system capacity, increased cooperation between the public and private health sectors, increased testing, shielding high-risk populations, and implementing gradations of social distancing measures, such as mandatory use of face masks and banning large public gatherings and crowded spaces, which are commonplace in urban India.

Relying solely on a herd immunity strategy could also be dangerous as it may lower the risk perception among younger populations, affecting their compliance with much-needed social distancing measures. It could also be viewed as an easy route out of the current lockdown and possibly lead to the easing of the government’s current response measures.

What India needs is a strategic, devolved, and long-term approach.

First, the central and state governments will have to implement a nuanced testing strategy that moves from a targeted approach focusing on high-risk individuals toward mass community testing. At the moment, the testing criteria include asymptomatic and symptomatic individuals with a travel history to high-risk areas—but travel as a criterion is irrelevant at this point as the country closed its international borders weeks ago.

It also includes asymptomatic, symptomatic, and high-risk close contacts of confirmed cases, symptomatic health workers, and hospitalized patients with respiratory illness; this criterion will need to be expanded to move toward mass testing (to catch asymptomatic cases among those who are unaware they might be infected) and repeat testing for health workers (who are constantly at risk of new exposure even if they initially test negative).

The central government will need to swiftly address current bottlenecks that hinder widespread testing, including shortage of rapid testing kits and delay of government approval for domestic test kits, and also incentivize domestic biotech companies to produce kits and private laboratories to conduct testing.

Second, state governments should ramp up their contact-tracing efforts at the district and block levels. This can be done by setting up, training, and supporting teams of contact-tracers including public health officials, police, front-line health workers, and community leaders and volunteers. Contact tracing and monitoring through visits and phone calls by teams can be supplemented by mobile-based tracking applications.

However, several of these apps, including Aarogya Setu—a contact-tracing app launched by the central government in India that has been downloaded by 50 million people—have raised privacy concerns, such as the possibility that the government could repurpose private information for reasons other than disease control. These ethical issues will need to be addressed if the government wants to ensure public trust and compliance.

Third, states can implement nuanced treatment and isolation strategies, such as separating patients with mild, moderate, and severe symptoms in different settings to manage cases effectively. This must be supplemented with staff management plans, such as splitting workforces into teams to ensure staff get rest and avoid attrition. China converted existing public venues into large-scale temporary “Fangcang” hospitals to isolate and treat patients with mild to moderate symptoms.

Similarly, the southern Indian state of Kerala equipped isolation wards in medical colleges, general and district hospitals, hostels, educational institutions, and unoccupied buildings. Private hospitals are struggling with low patient numbers and losses owing to the lockdown. State governments should seize the opportunity to increase the number of designated private hospitals and clinics for testing and treatment of COVID-19 and incentivize them to share their capacity by entering public-private partnerships and reimbursing private facilities for each case treated.

Fourth, India must invest and build the capacity of the public health system by addressing short-term needs like stockpiling of medicines, personal protective equipment, and ventilators, as well as long-term needs—such as hiring epidemiologists, data scientists, and immunologists—and strengthening health information systems.

Fifth, state governments should engage local communities by linking district and local health teams with community leaders and volunteers. With adequate support and supervision, local communities can play a key role in contact tracing, monitoring social distancing, shielding the vulnerable, and encouraging people to seek treatment when they need it.

All of these strategies will require central government financing, which means India must add to its current allocation of a mere 0.8 percent of GDP to health care. While central and state governments have announced cash and food transfers for low-income households, they can go a step further by integrating existing social welfare schemes, increasing cash transfers, and ensuring maximum coverage and transparency. Furthermore, the government will need to identify sectors that are the lifelines of the economy, such as small businesses and transport, and offer stimulus packages such as credit, cash grants, and tax relief, as well as creating back-to-work protocols for different sectors.

India cannot afford to remain in a prolonged lockdown, but letting the virus run rampant is certainly not the way out of this. While a herd immunity strategy is a seemingly attractive and easy path, it is little more than a Darwinian roll of the dice, which could result in the deaths of millions of Indians.

If the Indian government wants to save lives and livelihoods, then it will have to come out of the lockdown by expanding its testing, tracing, and treatment capacity, strengthening its public health system, and ensuring a socioeconomic safety net.

Devi Sridhar is a professor and chair of global public health at the University of Edinburgh. Twitter: @devisridhar

Genevie Fernandes is a postdoctoral research fellow at the University of Edinburgh.