DENVER (KDVR) — Depending on the measurements, Colorado is somewhere between the 16th and 23rd closest to herd immunity among U.S. states, while New England and northern Great Plains states are leading the way.
Nationally, 42.5% of the U.S. population has had at least one dose of the three vaccines available, some 141 million people. Between a quarter and third – 28.9%, or 96 million – are fully vaccinated.
Experts estimate herd immunity occurs in COVID’s case when 70-80% of the population has immunity through previous exposure to the virus or through vaccination. With 32 million cases, this makes for 173 million Americans who have either been infected or had at least one dose of the vaccine – just over half the U.S. public.
FOX31 Data Desk ran four different projections to determine where Colorado sits in race towards statewide herd immunity. In each, its ranking is close to its population ranking, somewhere near the 20th.
There are unknown factors that complicate projections.
First, it is unknown how many people who have recovered from COVID-19 have also gotten vaccinated. Maybe all did, maybe only a fraction.
Second, people with at least one dose become fully vaccinated in a matter of weeks. Herd immunity projections could concern either one number or the other.
Data Desk ran all four combinations: all people who are partially vaccinated plus all people who have been previously exposed, all partially vaccinated plus half previously exposed (to account for previous cases who got vaccinated after recovery), all people who are considered fully vaccinated plus all previously exposed and all fully vaccinated plus half previously exposed.
New England states are closest to herd immunity, led by New Hampshire.
In that state, 66% of the population has had at least one vaccine dose or been previously infected by COVID. Next are Rhode Island, Connecticut and Massachusetts with 62% each.
These four states top the national list even when only considering half the number of COVID cases.
Rankings do change when only accounting for fully vaccinated persons.
In this case, fully vaccinated people plus all people who have recovered, North Dakota is the closest state to herd immunity. Rhode Island, Connecticut, South Dakota and New Mexico follow.
Accounting for fully vaccinated persons but only half of previous cases, South Dakota becomes the closest to herd immunity with 42% of its population. Connecticut, Rhode Island, New Mexico and Wisconsin come next.
Colorado lands in the top half across all four measures.
It ranks 16th closest to herd immunity including all vaccinated and all previous cases, 17th with all vaccinated and half previous cases, 23rd with fully vaccinated and all previous cases and 21st with fully vaccinated and half previous cases.
These percentages range from 35-55% of the state’s population.