Nine drug companies issued a joint pledge on Tuesday that they would “stand with science” and not put forward a vaccine until it had been thoroughly vetted for safety and efficacy.

The companies did not rule out seeking an emergency authorisation of their vaccines, but promised that any potential coronavirus vaccine would be decided based on “large, high quality clinical trials” and that the companies would follow guidance from regulatory agencies like the Food and Drug Administration.

“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,” they said.

President Trump has repeatedly claimed that a vaccine could be available before Election Day, November 3, heightening fears that his administration is politicising the race by scientists to develop a vaccine and potentially undermining public trust in any vaccine approved.

“We’ll have the vaccine soon, maybe before a special date,” the President said on Monday. “You know what date I’m talking about.”

Three of the companies that signed the pledge are testing their candidate vaccines in late-stage clinical trials in the US: Pfizer, Moderna and AstraZeneca. But only Pfizer has said that it could apply to the FDA for emergency approval as early as October.

In the nine companies’ statement on Tuesday, they did not mention Trump, saying only that they have “a united commitment to uphold the integrity of the scientific process”.