Here are some: https://archive.is/T23eV https://archive.is/T23eV https://www.nature.com/articles/d41586-021-02187-1 https://www.nature.com/articles/d41586-021-0

Here are some: https://archive.is/T23eV https://archive.is/T23eV https://www.nature.com/articles/d41586-021-02187-1 https://www.nature.com/articles/d41586-021-02187-1 I think it would help everyone if we all used specific terms when discussing covid infections. From what I've gathered, the current generation of covid vaccines (mRNA, J&J, AZ) induce mainly a IgG immune response (as well as other things I know nothing about), but they certainly do not induce an IgA response. IgG is humoral immunity which protects your blood, and lower respiratory track somewhat, IgA is mucosal immunity which protects your upper-respiratory track (nose, mouth, etc) as well as other mucous membranes. Since covid typically first infects the nose, studies which I cannot find at the moment have shown that vaccinated individuals have only slightly less viral load in the nose than unvaccinated. At the onset of the curve however (first few days), they are the same. Viral load does not equate directly to infectivity, but from this we can say that vaccinated people can spread covid, whilst being asymptomatically infected. Saying you "have" covid is too vague, since you can "have" it in your nose, in your blood, etc.