Herd Immunity: garbage in-garbage out

“The concept of ‘herd immunity’ first materialized in the 1930s, when Johns Hopkins University’s Arthur Hedrich discovered that, after 55% of Baltimore’s population acquired measles (and thus immunity to measles), the rest of the population, or ‘herd,’ became protected. This concept provides today’s rationale for insisting that everyone be vaccinated.

‘If you only risked your own health by not getting vaccinated, that would be your business,’ mass vaccination advocates state. ‘But when your failure to get vaccinated endangers me or my child, that becomes my business.’ It’s a powerful argument, except for one thing—herd immunity in vaccinated populations has been repeatedly disproven.

But that too was insufficient—measles outbreaks occur even when the vaccinated population exceeds 95%, leading some to say a 98% or 99% vaccination rate is needed to protect the remaining 1% or 2% of the herd. But even that may fall short, since outbreaks occur in fully vaccinated populations.

‘The target would be to have 100% of the population vaccinated,’ Dr. Gregory Taylor of the Public Health Agency of Canada recently told CBC, voicing an increasingly common perspective among public health professionals. At that point, the balance of the herd that would be protected through mass vaccination would be precisely 0.

… But even vaccinating 100% of the population wouldn’t be enough, say scientists at the Mayo Clinic’s Vaccine Research Group, because the measles vaccine is a dud with some people, offering no protection at all, and its effectiveness wanes with others, even if they get boosters.

… In fact, herd immunity—so elusive today—fully existed prior to the vaccine’s introduction. Virtually 100% of the population then contracted measles, typically as children, giving everyone lifelong immunity—and future mothers the means to protect their offspring. In mass vaccinating us, scientists of the 1960s didn’t realize that infecting us with the measles vaccine—a weak version of the natural measles virus—would give us a weak version of the defenses our bodies develop to the real thing.

… Herd immunity sounds fine in theory. But as Stanford’s Dr. Obukhanych concluded, ‘As with any garbage in-garbage out type of theory, the expectations of the herd-immunity theory are bound to fail in the real world.'”

— Lawrence Solomon, research director of Consumer Policy Institute

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