Vaccine Shedding and people being stupid.

People denied access to shops because of vaccine shedding?

Now, I do know very well that people are stupid. Very stupid. Very. VERY VERRRRY stupid.

But, THIS one is on a whole other level.

I'm going to ignore the fact that vaccine shedding is simply not possible with the COVID-19 vaccines... BECAUSE THEY DON'T ACTUALLY CONTAIN ANY LIVE VIRUS TO SHED!!!!!!!

That is correct, this is not one of those "oh it is highly unlikely" things like the blood clots. This is literally impossible.

And Yes I'm going to ignore that one fact, which in and of itself COMPLETELY and UTTERLY destroys any argument in favor of barring service to someone on the grounds of having had a vaccine in the last X days.

How incredibly generous me!

And that is for the simple reason that even if it were not the case it SIMPLY. WOULD. NOT. MATTER.

Vaccine shedding is a phenomena which can occur with live attenuated vaccines. Which is to say, vaccines which use a weakened strain of the virus to provoke an immune response. The "shedding" typically takes place in the toilet, but every virus is different and even if it only comes out in your waste, there are still ways to spread it.

However, that being said, the viral load and the potency will effectively always be much lower than a natural infection in the wild from the virus strain it is meant to inoculate against.

If that were not the case, then it wouldn't make an effective enough attenuated virus to pass any health and safety trials. Every vaccine comes with potential side effects and to get certification basically anywhere you need to show that your vaccine is A) effective and B) more beneficial to the recipient than catching the virus.

Why does all of this matter?

So, if a vaccine CAN lead to shedding, what it sheds is the attenuated virus. Put another way, calling it "vaccine shedding" is just a way to rename what is happening so people can keep being stupid. "Shedding" is just people spreading a virus. Much the same as any infected person would. The only differences are how they contracted the virus, that it is much weaker strain and that they are much less likely to transmit it.

With that out of the way. Let's play make-believe. Pretend you live in a world where there actually is a live attenuated COVID-19 vaccine available and in circulation in your region. And two people want to come into your shop. 1 has recently had that vaccine and the other hasn't. Who poses a greater risk?

With no other information available, then statistically speaking it would be the person without the vaccine who is the higher risk. And this is for the simple reason that the normal, non-attenuated strains of COVID are the real threats to your employee and customer safety. 

If this is within maybe 1-2 days of getting the vaccine I'd say that the risk is about equal. The vaccinated person likely has no real defence against COVID yet, and it is completely possible that they had become infected with the actual disease prior to the shot and are still asymptomatic. So, they are really no more or less a threat at this stage than an un-vaccinated person.

But, if this is 1-2 weeks after the shot, the vaccine will have the immune system at basically the maximum level of safety. At this stage it is extremely unlikely this customer would be carrying COVID-19. Whereas the un-vaccinated individual is anyone's guess.

If this were several weeks later (amusingly a threshold which allows people back into the stores in many cases), then the immune response would have dropped in the vaccinated individual, especially if this was only part way through a multi-dose regimen. Their odds of catching COVID would still be substantially lower depending on the single dose effectiveness of this hypothetical attenuated vaccine. But, they would still present much less of a risk than an un-vaccinated individual.

So, as I said... while it is true that there are no COVID-19 vaccines approved in North America which could even cause viral shedding, it wouldn't particularly matter if there were. And, the threats that viral shedding could cause would be virtually identical to those of the virus they were being used against. Just in lower severity and likelihood.

It is kind of like saying you can't come into my shop if you have a water gun because there are hypothetical scenarios where it could used to injure or kill someone. But, it is OK to come in with concealed firearm.