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What is Herd Immunity?

Viruses don't go away without vaccines. Measles, a highly contagious virus, was eradicated with vaccination, but occasionally pockets of infection do erupt in susceptible groups who refuse to be vaccinated.

Herd Immunity was recognized in the early 1900s, first by veterinarians, and then in humans.  When a high enough percentage of individuals in a community are exposed to a virus, the rate of transmission and infection slows down because there aren't enough susceptible people to pass along the virus.  Herd immunity needs approximately 70% of a community to either have been infected or vaccinated. 

The vaccines in the US must be at least 50% effective in order to get FDA approval.  If 100 patients are vaccinated 50 of them would develop immunity and protection.  If many patients don't accept vaccination, we can do another calculation:  If 100 people are offered a vaccine, and only 60% get vaccinated, and only 50% of them develop a strong immune response, only 30 patients of the original 100 patients would be counted in the development of herd immunity.  READ BELOW


Dr.Tony Fauci, from NIAID/NIH, estimates that only 10% of the population in the US was infected so far.  Therefore vaccination is extremely important in the development of herd immunity to Covid-19.   

Bottom Line:  Develop a very safe vaccine, with high effectiveness (preferably 70%), and vaccinate as many people as possible.  Only then will our lives return to pre-pandemic freedom.  But we would still need to follow the Public Health Guidelines to control breakouts. 


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