When will the US reach herd immunity and what will it look like?
February 26, 2021. Summarized by summa-bot.
Compression ratio: 18.4%. 2 min read.
A year into the Covid-19 pandemic, it appears that trends have finally shifted in a positive direction. The country could be well on its way to herd immunity-- when enough people are protected against a disease that it cannot spread through the population.
The country could be well on its way to herd immunity, the point at which enough people are protected against a disease that it cannot spread through the population.
However, some new variants threaten progress, potentially lessening protection offered by vaccines and skirting some degree of natural immunity.
But if you had to put a number on it, what level of population protection is required to reach herd immunity against Covid-19?
We all expect that this virus is not different from other viruses and that we will reach a point that a sufficient number of people are immune so that the virus cannot jump any more.
Can we count those people toward herd immunity?
Lessler: In the short term, over the next six months or so, I would count everybody who's been infected and most people who have been vaccinated as immune.
Malaty Rivera: No. Herd immunity can only be discussed in the context of mass vaccination.
New variants potentially threaten levels of protection, both in terms of vaccine efficacy and possible reinfection.
In a completely susceptible population, the average person with the original strain would spread the virus to three people, so you need two people to be immune to start decreasing the spread.
But with some variants, the average person may spread the disease to around five people, so you need four people to be immune to cut the spread.
Mehta: We think vaccines will provide good immunity to most variants out there, but there are some -- particularly the variant first identified in South Africa -- that appear to have the ability to get around that and may alter our level of protection.
They don't represent a large group of people in this country, and I don't think they'll have tremendous victory when it comes to things like herd immunity.
Murray: If we can move from 25% of the population not being vaccinated to 10%, that really boosts herd immunity way up.