[BostonCard]

As a rough guide, herd immunity is achieved when 1 - 1/R0 of the population are vaccinated, adjusted for the efficacy of the vaccine.  So, if R0 is 2, as long as half the population is vaccinated you get her immunity when half the population is vaccinated.  If R0 is 3 (like COVID-19), you need 2/3 of the population to be vaccinated. If R0 is approaching 10 (like measels), you need 90% of the population to be vaccinated.  But again, this has to be adjusted for the efficacy of the vaccine.  This is high for measels, but if the COVID-19 vaccine is only 75% effective, then you will need a larger share vaccinated.

BC

[BostonCard]

As a rough guide, herd immunity is achieved when 1 - 1/R0 of the population are vaccinated, adjusted for the efficacy of the vaccine.  So, if R0 is 2, as long as half the population is vaccinated you get her immunity when half the population is vaccinated.  If R0 is 3 (like COVID-19), you need 2/3 of the population to be vaccinated. If R0 is approaching 10 (like measels), you need 90% of the population to be vaccinated.  But again, this has to be adjusted for the efficacy of the vaccine.  This is high for measels, but if the COVID-19 vaccine is only 75% effective, then you will need a larger share vaccinated.

BC