Data query for the data thread:
Herd immunity.
My understanding of how herd immunity works (in general) is that if an individual catches an infection, the immunity in their ring of contacts means that it is unlikely that the infection is passed on, and that if it is, it is only to a small number, who again have a ring of very largely immune contacts. This keeps outbreaks small and self-limiting.
The degree of immunity needed in the community for this to work will vary according to the infectiousness of the disease involved.
For Covid, where the aim of herd immunity is being targeted through vaccination, doesn't the fact that we are doing this via age group make the calculation very different?
People without immunity are not randomly distributed amongst the community, each surrounded by a largely immune 'ring'. Instead, the unvaccinated are very largely collected together (and largely in the most Covid--unsafe places such as schools, colleges etc).
So in this particular case, do we need to look, not at the overall vaccination / immunity percentage to achieve herd immunity, but the vaccination / immunity percentage in every age group?
So regardless of the percentage vaccinated 'of adults', or even 'of the whole community', there will not be true herd immunity that actually prevents outbreaks and spread until all age groups have achieved the critical vaccination / infection induced level of herd immunity?