Simple Herd Immunity Projections Using the standard epidemiological equation, Vc = 1 / Ɛ0 (1–1/R0), that assumes random mixing and random vaccine distribution. Vc is the threshold at which herd immunity is achievable using only vaccines. Ɛ0 = VE = Vaccine Efficacy, with 100% being a perfect vaccine that blocks infection (sterilizing immunity). R0 is the average number of people that are infected by each infected individual without any interventions. Five curves are plotted at VE = 100%, 95%, 85%, 75%, and 50%. The pink shaded region is the expected area that the Delta variant occupies. The two horizontal lines are the present vaccinated promotion of the US population 12 years and older (67%) and total (57%). If , herd immunity is impossible with vaccination alone. If , no treatment is needed for the disease to eventually extinguish itself given the assumption of random mixing. Source: Own work, CDC presentation, New York Times vaccinations on 12/2/21, and P. Fine, K. Eames, and D. L. Heymann, “‘Herd Immunity’: A Rough Guide,” Clinical Infectious Diseases, vol. 52, no. 7, pp. 911–916, Apr. 2011, doi: 10.1093/cid/cir007.
I spent several months reading dozens of academic research papers on COVID-19 while investigating the cognitive impact of mild disease. My research showed that concern of cognitive decline within the scientific community is serious and being researched intently.
I wrote an article to describe what I learned. In the article, I discuss population level statistics, MRI and PET imaging studies, and the scientific debate over the mechanism of action. I also discuss elements of strategy we will need to understand to fight back against the virus effectively.
The resulting article was published by Cosmonaut. You can read it here:
