Successfully rolling out a coronavirus vaccine by Nov. 1 will rely on clinical trials conducted at unprecedented speed, coupled with public release of research that shows it is both safe and effective, experts say.

Reaction to the Centers for Disease Control and Prevention’s letter to states to prepare for “large-scale” distribution of the vaccine in November — specifically, two days before the presidential election — triggered swift concern that political pressure could override commitments to safety.

“I want to see the data,” said Dr. Carlos del Rio, executive associate dean of the Emory University School of Medicine in Atlanta. “I need to show that there is true efficacy and safety.”