There are many more breakthrough cases with the delta variant. That said, the vaccines are still very good at combatting serious illness:
We continue to estimate that the risk of a breakthrough
infection with symptom upon exposure to the Delta variant
is reduced by seven-fold. The reduction of 20-fold for
hospitalizations, and deaths," Walensky said during
Tuesday's briefing.
There are many more breakthrough cases with the delta variant. That said, the vaccines are still very good at combatting serious illness: