A U.S. Centers for Disease Control and Prevention advisory panel is expected on Sunday to recommend Johnson & Johnson's COVID-19 shot for widespread use, a final clearance for the vaccine after it was authorized by U.S. regulators on Saturday. The Advisory Committee on Immunization Practices (ACIP) has played a major role in guiding states on how to allocate scarce doses, though states themselves have the final say in how they allocate shots. For previous COVID vaccines, the CDC panel discussed clinical considerations for patients including pregnant women and people with severe allergies, who were not studied in clinical trials.