Americans headed to pharmacies for COVID-19 vaccines are running into roadblocks and confusion due to new US guidance that abandoned broad support for the shots, contributing to the lowest vaccination rates since they were introduced. For the four-week period ended Oct 3, COVID immunizations were down about 25% nationally, according to IQVIA data in analysts' research notes. Steven Thompson, a 41-year-old financial professional from Salt Lake City, routinely gets the COVID shot through employer-sponsored health insurance. In September, he was told at a Walgreens pharmacy he needed a prescription. Utah, Georgia and Louisiana had been requiring prescriptions while awaiting US CDC guidance on who should get the shot. Thompson's children's pediatrician just sent prescriptions to Walgreens. His doctor required a...