Ignore herd instinct: Sero results do not point to herd immunity but the need to ramp up testing in target districts

How close has India moved to herd immunity? This question loudly raises its head every time a new jaw-dropping sero survey is released – such as when 57% sero positivity is reported from Mumbai slums, 51.5% in some Pune areas, or 28% in Delhi. Specific pockets of India do seem closer to herd immunity than most of the world. Majority opinion puts the herd benchmark at 60-70% of the population having antibodies, indicating exposure to the virus. But however energetic this discussion grows the bottomline is that, as a health ministry official said last month, for India herd immunity cannot be a strategic choice or option.

The virus is spreading across India unevenly, revealing different timelines in different regions. But the nationwide 27.6 lakh caseload as of Tuesday, which comes to 0.2% of India’s population, has given us a death toll near 53,000. Even while granting that there are a lot of unidentified infections, it should be clear that simply waiting for 70% virus spread in our population would amount to a catastrophic, unacceptable loss of lives.

Arresting the spread of the virus by all means possible remains the economic, moral and democratic imperative for the Indian nation. Every life matters. But especially when such colossal numbers are at stake, there cannot be any compromise on ramping up the necessary medical infrastructure. Until a vaccine or an optimal treatment is found, widespread testing remains the cornerstone for fighting virus transmission. High positivity rates in several parts of the country indicate how much testing still needs ramping up. Compare for example the 31.7% positivity rate of Raigad, Maharashtra and 26% of Darbhanga, Bihar to India’s average of 7.7%. High positivity indicates that only the sickest patients are getting tested, while asymptotic infections are not being picked up and they continue causing further infections.

It is also important to bear in mind that wherever the virus is allowed to run rampant, the battle against other diseases is weakened as are health services like children’s vaccination. On the upside, international developments like the saliva tests approved by US FDA or under trial in Israel could help smoothen the structural bottlenecks as they promise to be faster, cheaper and simpler. The holy grail would be at-home tests. Meanwhile, India should at least allow testing on demand.

This piece appeared as an editorial opinion in the print edition of The Times of India.