Pfizer CEO Albert Bourla said in an open letter on Friday that his company could apply for emergency federal approval of its coronavirus vaccine as soon as late November, noting that the drugmaker expects to have enough data on the treatment's safety and efficacy by then. That marks the first time a vaccine developer has specified when a vaccine might be available. "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," Bourla wrote in the letter. The Food and Drug Administration is in charge of reviewing and approving requests for emergency use. He added, "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." Thirty-seven states are seeing a rise in average new coronavirus cases; only one state — South Carolina — is down. At the same time, two vaccine developers have paused their trials due to safety concerns, with drugmaker Eli Lilly halting human testing and Johnson & Johnson pausing its trial this week due to a sick participant. Pfizer's guidance that it could apply for emergency use authorization by the end of November is a setback to President Donald Trump, who has asserted that a vaccine could be ready by election day on November 3. "There is a great deal of confusion regarding exactly what it will take to ensure its development and approval," Bourla said in the letter. Pfizer, which is developing the vaccine with BioNTech, must demonstrate that the treatment is effective in preventing COVID-19 in "at least a majority of vaccinated patients," he noted. Next, the vaccine must be shown to be safe. Lastly, the company must demonstrate it can manufacture the vaccine consistently "at the highest quality standards," Bourla said. Pfizer earlier this year signed a $1.9 billion pact to provide the U.S. government with 100 million doses of a COVID-19 vaccine. Americans would receive the vaccine for free, the pharmaceutical company said. The deal for the vaccine includes the right to purchase up to an additional 500 million doses.