Speaking of research:
https://www.wsj.com/articles/as-delt...d=hp_lead_pos5
1)breakthrough cases remain relatively rare, and 2)are much less likely to result in severe infections:
The Delta variant of the Covid-19 virus appears to be breaking through the protection vaccines provide at a higher rate than previous strains, a Wall Street Journal analysis found, though infections among the fully inoculated remain a tiny fraction of overall cases, and symptoms tend to be milder.
U.S. states counted at least 193,204 so-called breakthrough cases among vaccinated people between Jan. 1 and early August, according to data that health departments in 44 states and Washington, D.C., provided to the Journal. The figure represents 0.1% of the more than 136 million fully vaccinated people in those states and the capital.
[…]
Health departments said that breakthrough cases represented a tiny fraction of Covid-19 infections and resulted in very few hospitalizations or deaths.
Health officials say the milder cases are evidence that the vaccines are working well, though they add some people have misinterpreted the higher rate of breakthroughs with the Delta variant as proof that they are ineffective.
“Let’s be real, here: Breakthrough infections are sort of OK,” said Larry Corey, a virologist at the Fred Hutchinson Cancer Research Center in Seattle. “You get infected and you have a cold, maybe an achy fever for 24 hours. But you don’t end up in the hospital, and you don’t end up with that 2.5% chance of dying once you are hospitalized.”