Pfizer is set to apply for the FDA’s Emergency Use Authorization (EUA) for its COVID-19 vaccine at the end of November.

Last week, Pfizer CEO Albert Bourla posted an open letter on the company’s website in which he explained three important metrics that are needed for the vaccine candidate to seek EUA.

The experimental vaccine, developed by Pfizer and BioNTech, must be effective in preventing COVID-19 in at least a majority of vaccinated patients, according to Bourla.

He also emphasized that the vaccine must meet safety standards and the companies must demonstrate they are able to consistently manufacture the vaccine without compromising quality control standards.

President Donald Trump has constantly hinted that a potential vaccine will be ready ahead of the November 3 election. Even the White House has been playing a pivotal role in pushing the FDA through its EUA for convalescent plasma therapy, despite objections from several infectious disease experts.

Bourla’s letter distanced the vaccine candidate and Pfizer from the political affrays. The efficacy data of the vaccine is expected by the end of this month. The Pfizer CEO said they will have to wait until there is sufficient scientific data about the efficacy. But he said efficacy is not enough.

He wrote, “A key point that I’d like to make clear is that effectiveness would satisfy only one of the three requirements and, alone, would not be enough for us to apply for approval for public use.”

Bourla even said that the internal standards for the safety of the vaccine set by Pfizer and BioNTech are high, and they may apply for the EUA by the third week of November.

“Safety is and will remain, our number one priority, and we will continue monitoring and reporting safety data for all trial participants for two years,” Bourla added.

In September, BioNTech CEO Ugur Sahin touted the safety of the experimental vaccine and noted that patients who have received it have experienced only mild symptoms.

Bourla said the company began to heavily invest in the manufacturing of the vaccine since the initial days of the pandemic.

“The timelines above reflect our best estimates of when these important milestones could be achieved,” Bourla said. “So let me be clear, assuming positive data, Pfizer will apply for Emergency Authorization Use in the U.S. soon after the safety milestone is achieved in the third week of November.” “All the data contained in our U.S. application would be reviewed not only by the FDA’s own scientists but also by an external panel of independent experts at a publicly held meeting convened by the agency,” he added.