Pfizer is hoping to have a coronavirus vaccine ready for emergency use by late November.

Albert Bourla, the CEO of the Rockland-based drug maker, says they could ask US officials to clear the way for the vaccine by the third week of November.

The approval will be requested through the Food and Drug Administration.

Bourla wrote that November date represents the company's best effort and is still subject to change. He went on to write that Pfizer is moving at the speed of science, but while speed is important, safety is paramount.

"The vaccine must be proven effective, meaning it can help prevent COVID-19 disease in at least a majority of vaccinated patients. Second and equally important, the vaccine must be proven safe, with robust safety data generated from thousands of patients. And finally, we must demonstrate that the vaccine can be consistently manufactured at the highest quality standards," Bourla wrote.

Pfizer's new timeline comes after the CEO had repeatedly pointed out the possibility of a vaccine this month. He recently pledged earlier that politics would not play a role in the vaccine development.

Pfizer is developing the vaccine with the German biotech company Biontech. It's one of four drug companies currently in late stage clinical trials in the United States.