One thing I’ve never found the answer to: is a positive test evidence of disease? It seems to me that a vaccinated person inhales the virus just as readily as an unvaccinated person, but the vaccinated person’s immune system fights it off before symptoms (or before serious symptoms) appear.
In that case, wouldn’t it be normal and expected for vaccinated people to sometimes test positive, in the sense of “there exist copies of the coronavirus in the upper respiratory system”?
People become more contagious as there are more viral particles in their system. Vaccination inhibits replication (but less than 100%), so you would expect a vaccinated person to have a lower viral load after exposure than an unvaccinated person. They might also have more symptoms, because some symptoms are immune responses and the whole point of vaccination is to give you a stronger response at an earlier viral load.
Vaccination inhibits replication (but less than 100%),
But not automatically everywhere in the body. To inhibit replication in the upper respiratory system you need mucosal immunity.
RaDVaC could potentially provide that but the approved vaccines don’t. The approved vaccines only give you a response once the virus attacks deeper parts then your upper respiratory system.
I may have experienced this last week, after having a mild sub-detectable exposure. It felt a lot like after shots 2, 3 and 4. But I still haven’t tested positive.
There is no one vaccinated person. Getting a load high enough to trigger a positive test is less likely but still possible post-vaccination. The interaction with symptoms is weird because symptoms are caused by both viral load and immune response.
This lends credence to my theory about last week’s exposure. Six negative rapid antigen tests and two negative PCR tests over the course of the seven days following the possible exposure, but I felt like hell about three days after.
I don’t think any of the tests are expected to return a positive result when the tested person’s viral load is extremely low. You can get a positive result and remain asymptomatic, but I think that’s only supposed to happen when the virus has got into you in a meaningful way, i.e. multiplied itself a bunch of times—not when you just happen to have recently breathed in a few virus particles.
Fair enough. The question is then, does a vaccinated person’s immune system take care of the virus so fast that the viral load remains “extremely low” enough to result in a negative test?
That seems counterintuitive given that Elizabeth says vaccinated people are more likely to be symptomatic, but I suppose it’s possible that the immune system would trigger covid-19 symptoms even while maintaining a low viral load.
My model is that the vaccine basically gives your immune system a head start, so your chances of each of the following (conditional on a better outcome not having already happened) are higher than they otherwise would be:
clearing the virus before it replicates enough to be noticable, either via symptoms or a positive test;
clearing the virus after it is noticeable, but before anything serious happens;
clearing the virus after it causes serious disease, but before it kills you.
So the answer to your question would be ‘sometimes’—more often than if they were not vaccinated, but of course non-vaccinated people do it significantly >0% and vaccinated people significantly <100% of the time.
(Sorry if this misses your main point, btw—I’m not being deliberately obtuse, I’m just not completely sure what your broader point is, so I’m focussing on the specific questions.)
One thing I’ve never found the answer to: is a positive test evidence of disease? It seems to me that a vaccinated person inhales the virus just as readily as an unvaccinated person, but the vaccinated person’s immune system fights it off before symptoms (or before serious symptoms) appear.
In that case, wouldn’t it be normal and expected for vaccinated people to sometimes test positive, in the sense of “there exist copies of the coronavirus in the upper respiratory system”?
People become more contagious as there are more viral particles in their system. Vaccination inhibits replication (but less than 100%), so you would expect a vaccinated person to have a lower viral load after exposure than an unvaccinated person. They might also have more symptoms, because some symptoms are immune responses and the whole point of vaccination is to give you a stronger response at an earlier viral load.
But not automatically everywhere in the body. To inhibit replication in the upper respiratory system you need mucosal immunity.
RaDVaC could potentially provide that but the approved vaccines don’t. The approved vaccines only give you a response once the virus attacks deeper parts then your upper respiratory system.
I may have experienced this last week, after having a mild sub-detectable exposure. It felt a lot like after shots 2, 3 and 4. But I still haven’t tested positive.
Is the vaccinated person’s lower viral load enough to trigger a positive test, especially for those with symptoms?
If it is, shouldn’t we be thinking of “reinfections” as those cases of serious disease, rather than simply positive tests?
There is no one vaccinated person. Getting a load high enough to trigger a positive test is less likely but still possible post-vaccination. The interaction with symptoms is weird because symptoms are caused by both viral load and immune response.
This lends credence to my theory about last week’s exposure. Six negative rapid antigen tests and two negative PCR tests over the course of the seven days following the possible exposure, but I felt like hell about three days after.
(disclaimer: no expertise)
I don’t think any of the tests are expected to return a positive result when the tested person’s viral load is extremely low. You can get a positive result and remain asymptomatic, but I think that’s only supposed to happen when the virus has got into you in a meaningful way, i.e. multiplied itself a bunch of times—not when you just happen to have recently breathed in a few virus particles.
as a quick citation, see the data here on false negative rates: https://www.nature.com/articles/s41598-021-88498-9
Fair enough. The question is then, does a vaccinated person’s immune system take care of the virus so fast that the viral load remains “extremely low” enough to result in a negative test?
That seems counterintuitive given that Elizabeth says vaccinated people are more likely to be symptomatic, but I suppose it’s possible that the immune system would trigger covid-19 symptoms even while maintaining a low viral load.
My model is that the vaccine basically gives your immune system a head start, so your chances of each of the following (conditional on a better outcome not having already happened) are higher than they otherwise would be:
clearing the virus before it replicates enough to be noticable, either via symptoms or a positive test;
clearing the virus after it is noticeable, but before anything serious happens;
clearing the virus after it causes serious disease, but before it kills you.
So the answer to your question would be ‘sometimes’—more often than if they were not vaccinated, but of course non-vaccinated people do it significantly >0% and vaccinated people significantly <100% of the time.
(Sorry if this misses your main point, btw—I’m not being deliberately obtuse, I’m just not completely sure what your broader point is, so I’m focussing on the specific questions.)