A group of drug companies competing with one another to be among the first to develop coronavirus vaccines are planning to pledge early next week that they will not release any vaccines that do not follow rigorous efficacy and safety standards, according to representatives of three of the companies.

The statement, which has not yet been finalised, is meant to reassure the public that the companies will not seek a premature approval of vaccines under political pressure from the Trump administration.

President Donald Trump has pushed for a vaccine to be available by October — just before the presidential election.

(In India, the Indian Council of Medical Research, the country’s apex health research agency, had suggested in July that clinical trials on home-grown candidate vaccines should be fast-tracked for a possible launch by August 15. The council clarified within a day that the directive was merely intended to cut red tape and not to bypass necessary scientific processes, adds our Delhi bureau.)

The manufacturers that are said to have signed the letter include Pfizer, Moderna, Johnson & Johnson, GlaxoSmithKline and Sanofi.

Regulators at the US Food and Drug Administration have been discussing making their own joint public statement about the need to rely on proven science, a move that would breach their usual reticence as civil servants.

Three companies — Moderna, Pfizer and AstraZeneca — are testing their candidates in late-stage clinical trials.

Pfizer’s chief executive said this week that the company could see results as early as October, but the others have said only that they plan to release a vaccine by the end of the year.

If the competing companies are among the first to bring a successful vaccine to market, they could earn major profits and help rehabilitate the image of an industry battered by rising drug prices.

But if a vaccine turns out to have dangerous side-effects for some people, the fallout could be catastrophic. It could also broadly undermine trust in vaccines, one of the great public health advances in human history.