Couldn't it reach such a percentage with a R0 being lower than 10? If your R0 is 2.5, herd immunity will make the current R value go under 1 when 1 - (1 / 2.5)

Couldn't it reach such a percentage with a R0 being lower than 10? If your R0 is 2.5, herd immunity will make the current R value go under 1 when 1 - (1 / 2.5) = 60% of the population got infected. While that means that the epidemic will stop growing exponentially, the virus will not stop propagating, as there will still be a non-exponential propagation of the virus (e.g. if 10% of the population is still infectious at the time herd immunity is reached -- when R becomes 1 --, we should expect at least 10% more infections). Or am I missing something?