The biopharma firms said in a joint statement that they would follow “high ethical standards and sound scientific principles” in their efforts to study and produce an inoculation that could help end the COVID-19 pandemic.

“We believe this pledge will help ensure public confidence in the rigorous scientific and regulatory process by which COVID-19 vaccines are evaluated and may ultimately be approved,” says the statement from AstraZeneca, BioNTech, GlaxoSmithKline, Johnson & Johnson, Merck, Moderna, Novavax, Pfizer and Sanofi.

The companies added that they would not seek approval or emergency authorization for a vaccine until it is shown to be safe and effective through a so-called Phase 3 clinical trial, which generally involves a large number of participants and a scientifically rigorous design.

Such studies are currently underway for several vaccine candidates, including those developed by AstraZeneca, Moderna and Pfizer, which is collaborating with BioNTech.

That indicates the leaders of the vaccine race in the US won’t take Food and Drug Administration Commissioner Stephen Hahn up on his offer to possibly fast-track a shot by granting an emergency use authorization before Phase 3 research is complete. Such an authorization would make the vaccine available to certain groups before it is fully approved.

The pledge came amid a push by the Trump administration to distribute a coronavirus shot quickly through Operation Warp Speed, a federal initiative that has committed billions of dollars to vaccine research and development.

President Trump suggested Monday that a vaccine could be ready as soon as next month, and the Centers for Disease Control and Prevention recently told states to be ready to distribute one by Nov. 1 — a timeline that runs close to the Nov. 3 presidential election.

The drugmakers said their pledge was consistent with the FDA’s guidance for developing a COVID-19 vaccine, which requires that “scientific evidence for regulatory approval must come from large, high-quality clinical trials that are randomized and observer-blinded.”

“FDA has established clear guidance for the development of COVID-19 vaccines and clear criteria for their potential authorization or approval in the US,” the statement says.

“FDA’s guidance and criteria are based on the scientific and medical principles necessary to clearly demonstrate the safety and efficacy of potential COVID-19 vaccines.

The FDA did not immediately respond to a request for comment Tuesday morning.