This idea of vaccinated people protecting the vulnerable was extrapolated from following historical dynamics of naturally immune populations. There was an assumption that vaccines would do the same thing, and that assumption turned out to be, admittedly in the medical literature, dead wrong.
In the 1920, when Dr. A. W. Hedrich tracked measles disease in Baltimore, MD, is where this came from. And just prior to a major epidemic, the proportion of the population under 15 estimated to be susceptible ranged from 45 to 50 percent. And at the end of those epidemics, the proportion dropped to 30 and 35 percent, which meant that 15 percent of the childhood population would be infected at any given time.
That’s not very many people, certainly far less than they would have us believe the old days used to be like…. and very young babies and adults didn’t get measles like they get today. By the age of 20, 95 to 99 percent of the population was life-long immune to measles from acquiring clinical measles virus infection.
Today, we have vaccines that are supposed to mimic that herd dynamic, but they’re not doing the job. And some vaccines don’t eradicate the target microbe, so they have no bearing whatsoever on herd immunity, so that argument is lost straight out of the box.
— Suzanne Humphries, MD, nephrologist