Herd immunity is both mystical and mythical: NTAGI chairman N K Arora

Herd immunity works when immunised and unimmunised individuals are mixed in a true random process and around 80 per cent are immunised, said Arora

As India scales up its Covid vaccination drive with a target of immunising its entire adult population by the end of this year, N K ARORA, chairperson, National Technical Advisory Group on Immunisation, says herd immunity is a myth. Arora explains why achieving 100 per cent immunisation is necessary to break the transmission cycle. In conversation with Sohini Das, he also assures that vaccines are working against the new strains. Edited excerpts:
 
Once we cover 70 per cent of the population, we achieve herd immunity. Is that remotely true?
 
Herd immunity is both mystical and mythical. It is