Like Manaus in Brazil, studies suggested that up to half the population in some of India’s biggest cities had already been infected in the first wave, meaning fairly high immunity in the population. “I think the problem is that what we are seeing is that this idea of herd immunity is messy,” said University of Manitoba virologist Jason Kindrachuk.

what it means is that it's answering the question about whether the vaccines are protective against the variants or not.

i'm not arguing against vaccination, and especially not if you're an older person. but, we need to stop thinking about these vaccinations as being one-off - it's too late for that. the virus has clearly already mutated beyond that.

https://nationalpost.com/news/canada/covid-19-india-canada-herd-immunity