Rakesh Wadhwa:

How does the concept of herd immunity work and is that a plausible solution who adopt?

Dr. Ramanan Laxminarayan:

So herd immunity is not a strategy. Herd immunity is an inevitable consequence of a disease spreading to a population. It is not that we actively seek out herd immunity. Herd immunity simply means that you don't have to vaccinate a hundred percent of our population to protect everyone.

Hundred percent of the population will not get the disease in order to be protected. In your mind Think of a hundred people in a room. Okay. Think of a hundred people on there and they're all playing passing the parcel. They are passing the parcel someone else.

But let us say that 65 people in the room was standing where they are, are people who if you give the parcel to, they will not pass anymore because they are immune they can take the virus. They can't give it to anyone else. So imagine that you have a hundred people and 65 of them cannot pass the parcel anymore. You can understand that that passing the parcel game will come to an end pretty quickly because. The virus is going to hit these dead-ends or these immune people and won't transmit further. So herd immunity is a simple concept which basically says that the disease dies out not when everyone is infected but when some proportion like 65% and why 65% because it's a pretty exact mathematical formula for herd immunity. And across the country, ICMR said that 0.73% was impacted except for the containment areas back in early May.

So including those areas might've been about 1-1.5% today. We may already be at 5% - 6% - 7% of people who are already exposed to the virus. So I d know. I don’t want to sound casual but getting from 5-6% to 55-60% is not that far and we might get there very soon.