We won't reach "herd immunity" for Covid 19 and it is NOT just due to those that did not choose to get vaccinated. Unlike Smallpox (our gold standard for disease eradication by vaccine), the current Covid vaccines are effective in preventing bad disease outcomes (ie death) but appear to not prevent transmission (based on equivalent viral level/cycle thresholds in Provincetown outbreak between vaccinated and non-vaccinated) and also do not fully prevent reinfection (again shown in the large outbreak). Also, unlike smallpox, the symptoms of Covid overlap with many other respiratory conditions and colds thus spread during the highly transmissible early phase of illness is expected.

So long as vaccinated individuals can still contract the disease (appears true), there is a delayed quarantine or missed diagnosis of disease (symptoms are not obvious like smallpox), and disease is easily transmitted (even more true with Delta), the disease will persist in the population.

**The proceeding is opinion based on current evidence as outlined within this Blogpost. If you have evidence to present that is contrary to this opinion, please provide to evidence@scottshortmd.org.