Wouldn’t it be funny if Covid-19 was gone by the time they came up with a vaccine for it? It could well happen. From Joseph Mercola at lewrockwell.com:
If a novel virus is introduced to a population, eventually enough people acquire natural immunity so that the number of susceptible people declines. When the number susceptible is low enough to prevent epidemic growth, herd immunity is said to have been reached.
In the early days of the COVID-19 pandemic, some experts estimated that 70% of the population or more may need to gain immunity before COVID-19 would be under control. Now, experts are suggesting the percentage may be far lower, and some areas may already have reached what’s known as the herd immunity threshold (HIT).
Scientists: COVID Herd Immunity Threshold Lower Than Thought
According to The New York Times, more than a dozen scientists said in interviews that the HIT for COVID-19 is likely 50% or lower. “If that’s true, then it may be possible to turn back the coronavirus more quickly than once thought,” the Times reported,1 and perhaps without the need for a vaccine.
Herd immunity is calculated using reproductive number, or R-naught (R0), which is the estimated number of new infections that may occur from one infected person.2 R0 of below 1 (with R1 meaning that one person who’s infected is expected to infect one other person) indicates that cases are declining while R0 above 1 suggests cases are on the rise.
It’s far from an exact science, however, as a person’s susceptibility to infection varies depending on many factors, including their health, age and contacts within a community. The initial R0 calculations for COVID-19’s HIT were based on assumptions that everyone has the same susceptibility and would be mixing randomly with others in the community.