Why herd immunity may not work

On Sunday, as India crossed six million Covid-19 cases, the Union health minister Harsh Vardhan said the country is far from achieving herd immunity. The minister cited the soon-to-be released findings of the second nationwide serological survey. The reality is that not enough Indians have built an immunological protection that could allow for going back to prepandemic behaviour.

What is also established is that India cannot pursue a herd immunity-focussed strategy. Letting the virus run its course will overwhelm the health care system. Mumbai is believed to have faced this scenario. In Delhi, hospital beds dwindled rapidly before additional resources were mobilised. Additionally, some research suggests individual immunity may not last long enough to prevent future infections, making herd immunity an even riskier gamble. Many scientists have pointed out that herd immunity is a scientific tenet that cannot be used in the context of infection-acquired protection; it is possible only through an effective vaccine. And since vaccines are at least another year away, the minister’s comments are a reminder that India must keep its focus on preventive measures as it heads into the festive season. Its citizens are battling behaviour fatigue and economic compulsion and may not adhere to social distancing and compulsory face-covering. It is important to address these while keeping distractions like herd immunity aside.