|%||of unvaccinated people will catch Covid|
|%||of everyone will end up getting Covid*|
|%||of vaccinated people will get breakthrough Covid|
*not including people who get effectively vaccinated after they get sick
Final Vaccination Rate %
Vaccination effectiveness %
Final Variant Reproduction Number (Delta Variant is estimated to be R0 = 6 to 8)
|Reproduction Number||R0 =|
|Herd Immunity Threshold||%|
|Final Total Immune||%|
|Reached Herd Immunity?|
|Immune because of Vaccination||%|
|Immune because they got sick||%|
|Chance of getting Sick if Unvaccinated||%|
|Chance of getting sick if Vaccinated||%|
This page makes the assumption that Covid will continue spreading until we reach herd immunity. This is a reasonable assumption since so far we've seen that if R gets below 1 we relax restrictions until Covid starts spreading again (i.e. R > 1). This will keep happening until R CAN'T be above 1 because we've reached herd immunity.
The herd immunity threshold is related to the reproduction rate:
Immunne threshold = 1 - 1/R0The delta variant is currently estimated at R=7 or 8. Each variant has a been a bit better at spreading, so we may well find ourselves dealing with a higher R before this is over.
The percentage of folks who are immune is
Immune = (%vax * vaxEffectivness) + %sick - %doubleSafePeople who get sick AND then are vaccinated would count twice if we didn't account for them. In the calculation above I DON'T include these people in the "Immune because they got sick" bucket (unless they also fall in the vaccine was ineffective bucket).
The percentage that get sick is
1 - Immunity Thresholdand the total vulnerable is
(1 - vaccinated) + (1 - vaxEffectiveness) * vaccinatedSo the final equation for how likely you are to get sick if unvaccinated
P(sick if unvaxed) = ((1 - 1/R0) - (vax%*vaxEff))/(1 - (vax%*vaxEff))
As you can see from playing around with the sliders, getting to a high vaccination rate is very important if we want to prevent a lot of people from getting sick. We also need to quickly stop Covid so we don't generate new variants with higher R0.