https://www.westernjournal.com/new-study-argues-covid-herd-immunity-may-alread
A new study that pushes back against some accepted notions of how the coronavirus is transmitted argues that herd immunity might already have been reached in some parts of the nation.
The study, “Persistent heterogeneity not short-term overdispersion determines herd immunity to COVID-19,” was published Aug. 10 in the Proceedings of the National Academy of Sciences.
It pointed out that current infection models assume there are so-called “super-spreaders,” which are a small number of individuals who, because of their social activity, pass the virus along to large numbers of other people.
In this model, everyone everywhere has an equal chance of infection.
Writing at Reason, Ronald Bailey offered an interpretation of what the study thinks is happening instead.
Bailey wrote that the researchers define a concept they call heterogeneity “as the biological and social susceptibility of individual members of the population to COVID-19 viral infection.”
The study relies on what is called “biological heterogeneity,” which includes “the strength of immune responses, genetics, age, and comorbidities,” and social heterogeneity, which measures close contacts among individuals, according to Reason.
“Taking the effects of biological and social heterogeneity on COVID-19 transmissibility, the researchers calculate that the herd immunity threshold is likely somewhere between 20 and 30 percent of the population,” Bailey wrote.
The researchers then conducted a modeling exercise of what might happen this fall, which has been cited as a time when a feared second wave of coronavirus infections might take place.
