Posted by: UFO
Posted by: KenN
And you can still get the virus in your lungs and expel it in droplets as you exhale. Your immune system may be fighting off the virus, but it's still live.
And when an immune person passes on live virus to others, the term is 'shedding'.
This is a good summary, however we need to also consider viral load in addition to viral shedding.
The science continues to evolve all things Covid related. But there does appear to be a similar decrease in infectiousness post vaccination at a similar rate of the efficacy of the vaccine, and this doesn't appear to be surprising to specialists in the field.
Basically say your body coughs up 1000 virus particles per droplet pre vaccination, and post vaccination you can still be a carrier but you are only coughing up 100 virus per droplet. If it takes 500 virus per droplet to get overcome by Covid, even though you're still a carrier post vaccination, your risk of transmission is many times lower.
Of course this is an oversimplification with made up numbers, but it highlights why we've adopted a significantly increased (not necessarily scientifically informed or supported) gap between the 2 doses in light of a shortage in available vaccines, you could view it as a population level harm reduction approach.
^^ This is a good explanation on a overall level. A vaccine would not be effective at all if you were still able to shed the same amount of virus as you did without it. An effective vaccine will drive down the viral load you are able to shed to levels low enough that you should no longer be able to pass an infectious dose onto someone else.