Member-only story
How many people from each state need a COVID-19 vaccine?
And why we can’t rely on herd immunity — for now.
With the recent news of three new (and effective) COVID-19 vaccines rounding the corner on FDA approvals, there’s reason to be optimistic with the end of the pandemic within sight. But there’s always a catch, right?
While the vaccines will go to those most at risk for getting very sick or spreading the virus, it will take a while before we see the impact of vaccinations to take hold. In the first phase of distribution, there will only be enough to vaccinate about 20 million Americans — about 6 percent of the population.
Vaccine front-runner, Moderna, estimates the effectiveness of their covid vaccine to be about 94.5%. But with unique cooling requirements, there will be several infrastructure and transportation hurdles to overcome. That’s why we can’t rely on herd immunity just yet and need to play it safe. Even at an astounding 94.5% effectiveness, we would need to vaccinate at least 67% of the population.
Although the official reproductive number is a moving target, early estimates suggest it’s between 2.5–3.5. Using a simple epidemiological equation, this is about how many people from each state would need to get vaccinated to achieve herd immunity:
