Several people who I work with got the vaccine and have now had to quarantine the past couple weeks because of contracting Covid....and getting sick. I think we're past "breakout cases." So, I'm going to assume it's waning of their vaccines combined with the Delta variant. Doesn't bring much encouragement. It's been well over 6 months, which they seem to think is the period it starts to lose its effectiveness. Doesn't seem like a very long protection period...