Earlier in the day, STAT News reported that Pfizer CEO Albert Bourla and Moderna CEO Stephane Bancel were both invited to attend the gathering but turned down invitations. The senior official refuted this, saying that attendance of the Food and Drug Administration’s (FDA) top regulatory official, Peter Marks’, forced the White House reshuffle plans to avoid a conflict of interest.

"There’s a question about vaccine companies – Pfizer and Moderna – and their participation [in the summit]. We were in discussion with them in the planning process. Ultimately, the determination was, we had Peter Marks of the FDA participating and there was a change of direction in light of the fact that we would have the regulator participating in the event, it was more appropriate not to have the vaccine companies with pending applications before the FDA also participating in that event," the senior official said on Monday.

The White House deemed that the participation of Marks, the Director of the Center for Biologics Evaluation and Research and the man who will ultimately make the final determination on Pfizer’s and Moderna’s Emergency Use Authorization (EUA) applications, would go further towards instilling confidence in a vaccine then attendance by pharmaceutical reps, a second administration official added.

The officials also countered a New York Times report that alleged the Trump administration passed up an opportunity to procure additional doses of the Pfizer vaccine. An administration official said that the administration could not have been offered 400 million doses of a vaccine while it was in the pre-clinical phase.

The Trump administration has publicly clashed with Pfizer in recent weeks over its involvement in the administration’s Operation Warp Speed and the timing of a data release showing its vaccine to be highly effective, the initial report had said.

Trump has repeatedly claimed credit that the new vaccines were developed in record time and for making plans for the vaccines’ delivery throughout the United States.