Chalk my family up for four breakthru cases. My 10-year-old daughter got flu-like symptoms on 1/17 that lasted 2-3 days. The rest of us were all sick within a week. The other daughter had the same 2-3 day experience. My wife and I had a week of flu symptoms and another week or so of lingering cold symptoms. I still have a hint of cold symptoms ( I often have lingering colds, or did before Covid), but am basically back to normal and am testing negative.