It depends on the infectivity of the virus as to what the actual percentage is- its not an across the board number. Though you probably already knew that and were just politicizing.or is it just a number the President threw out because we were on track to get there anyway?
https://www.webmd.com/lung/what-is-herd-immunity#1
70% is a guess as to how many people need to be in inoculated before the spread of the virus will steadily decrease. We will only know the actual number once we hit it and case counts steadily and mostly continually fall. It won’t happen uniformly across the country because different areas will have different levels of vaccination.
As new more infectious variants continue to develop the number of vaccinated people needed to have herd immunity will increase.
The other thing people often seem to forget when discussing the percentage of people needing vaccination to achieve herd immunity is that the percentages quoted of vaccinations usually only count the percent over age 16. For instance in my county 85% have had one shot and 71% are fully vaccinated. But that ignores that 45,000 of the county’s 255,000 people are under 16. When you add in the kids the number of people vaccinated are 70% one shot and only 50% fully vaccinated.
Exactly. The estimate of R0 for covid, the average number of infections each infected person causes in others, is believed to be roughly 3. Without vaccinations or other mitigation efforts (masks, distancing, limiting gatherings, etc) the disease explodes across the population because that’s an increditbly high R0. One infected person infects threw more, who infect nine more, who infect 27 more, etc. The flu, by comparison is thought to have an R0 of about 1.5.
Herd immunity happens when the number of people available to get infected due to not being vaccinated is low enough that each infected person infects, on average, less than one person. With an R0 of 3 that means that roughly 2/3 of the population needs to be vaccinated so that 2 of the 3 people the infected person would have infected won’t get sick.
Note that some of the new variants have a higher R_nought....
Also consider that unvaccinated people serve as an R&D lab/ecosystem for the virus to develop more virulent strains...
Further consider that dorks who refuse to social distance and wear masks are helping breed a better virus...
Frankly, I'm about to withdraw from any form of public service, I've given up.
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