Originally Posted by
bob10
That is an interesting theory. I'm not qualified enough to critique it, but looking at overseas locations like India, or even the UK, it seems that if the virus was out there in a large part of our population, we'd have more people in hospital.
I read an interesting article in the New York Times which stated some ' experts 'had done some modelling that showed if you used a vaccine with 90% efficacy against infection you can reach herd immunity if 66% of the population is vaccinated. Using a lower efficacy vaccine, many more people need to be vaccinated. For example if your vaccine efficacy is 60%, you need 100% of the population to be vaccinated to reach herd immunity. The AZ has been said to have an efficacy of 82.4 % after a second dose but only 54.9% with one dose. Some one with better math could work out the percentage of population which needs to be vaccinated to reach herd immunity in Australia .