Herd immunity and covid-19

By Dr. Stephen A. Berger WHAT IS HERD IMMUNITY? It stands to reason that a contagious disease should disappear from a population when a sufficient percentage of potential victims – “the herd” has become immune. This outcome may arise because a massive number of individuals have been either infected or vaccinated. Most authorities dealing with COVID-19 have set the goal for herd immunity at >60 percent; however, the precise percentage for any infectious disease will depend on many factors involving demography, virulence, route of infection, etc.    HAS AN INFECTIOUS DISEASE EVER BEEN ERADICATED BY REACHING HERD IMMUNITY? Infectious Diseases have been known to reach herd immunity, however, none have been permanently eradicated by it. For instance, although there was an observed decrease of measles infections during the 1930s, recent outbreaks indicate the disease is far from being eliminated – despite effective vaccination measures introduced in 1963.   IMPORTANT CONSIDERATIONS As many countries enter into a second-wave of this pandemic, the bottom-line question for those who advocate the achievement of herd immunity through mass infection of the population will be one of cost-benefit.  This prompts a few thoughts and questions. Any program to actively infect large numbers of individuals will begin with the isolation of the elderly and other high-risk populations. How many countries are truly equipped to house, feed, isolate, and treat millions o...
Source: GIDEON blog - Category: Databases & Libraries Authors: Tags: Epidemiology Examples News Source Type: blogs