start giving us answers to what is the rate of break through infections. is it one in a 1,000 or one in ten or one in two. we literally don't know what is the rate of infection and the likelihood of that rate of infection ending up in others. >> reporter: the vaccines do work at preventing serious illness. polo sandoval, cnn, new york. thanks contributor. dr. abdul sayed. we appreciate you spending part of your week end with us. as covid cases tend to surges, some places are telling people to mask up again regardless of vaccination status. i want you to listen to what the surgeon general had to say about masking just last night. >> if you are living in an area where there's a lot of virus circulating, if you happen to have somebody at home who's