RE: Official live update of spread of COVID19
September 10, 2021 at 6:43 am
(This post was last modified: September 10, 2021 at 6:44 am by BrianSoddingBoru4.)
(September 10, 2021 at 2:05 am)Ronaldo Wrote: @BrianSoddingBoru4
At least you are able to hold a civilized conversation...
Just answer this one question...
How can a vaccine provide herd immunity when it doesn't provide individual immunity???
Because it provides resistance. The number of vaccinated people able to catch/transmit COVID is a tiny percentage. But this is a good thing - if they catch it, they're going to have milder symptoms. If they transmit it, anyone they infect is going to get a weaker version of COVID, after which they're going to be able to manufacture their own antibodies.
No vaccine provides 100% immunity - never have, never will. If you get an annual flu shot, you can still get influenza, if you get a measles vaccine, you can still get measles. It doesn't mean you
will, it means you
can (although your odds of actually doing so are drastically reduced).
But the more people who take a vaccine,
even without a guarantee of full immunity, the more likely herd immunity will take place. Like this:
Let's say you've got a sample size of 1000 people (just because that's an easy number to work with), all of whom are at some risk of COVID. A vaccine is developed which provides 95% immunity, and half of your sample are vaccinated. Now, that half of the population has a 5% chance of infecting the other half, so let's assume they do so. 5% of 500 is 25 people. So now, you've got 25 new cases instead of a potential 1000 (if no one was vaccinated). The 25 new cases will likely show milder symptoms and recover more quickly than if they had been infected by unvaccinated people. These 25 now have Coronavirus antibodies. While still contagious, these people may infect other unvaccinated people, and the process repeats. Over time, the 1000 people in the sample will either 1) be vaccinated or 2) have antibodies acquired through infection, and the entire population has gone from being at risk of dying from COVID to being at risk of a mild form of COVID. And bingo! - herd immunity.
Think of it as the the difference between catching Dengue fever and having the sniffles.
Boru