I find an interesting related item to be the ~30% of people in the AZD1222 (AstraZeneca) study who got COVID after being vaccinated. They reported that in this

I find an interesting related item to be the ~30% of people in the AZD1222 (AstraZeneca) study who got COVID after being vaccinated. They reported that in this subgroup, there were no severe infections, nor any hospital visits, confirming the parent's hypothesis that some people might not get full immunity, but still benefit from the vaccine.