Operation Warp Speed, the federal effort to rush a vaccine to market, has promised Pfizer $1.95 billion to deliver 100 million doses to the federal government, which will be given to Americans free of charge. But Dr. Jansen sought to distance the company from Operation Warp Speed and presidential politics, noting that the company — unlike the other vaccine front-runners — did not take any federal money to help pay for research and development.

“We were never part of the Warp Speed,” she said. “We have never taken any money from the U.S. government, or from anyone.”

She said she learned of the results from the outside panel of experts shortly after 1 p.m. on Sunday, and that the timing was not influenced by the election. “We have always said that science is driving how we conduct ourselves — no politics,” she said.