Pfizer and BioNTech on Friday submitted to the US Food and Drug Administration for emergency use authorization for their coronavirus vaccine candidate. This is the first coronavirus vaccine to seek regulatory clearance in the United States. “It is with great pride and joy and even a little relief that I can say that our request for emergency use authorization for our Covid-19 vaccine is now in the FDA’s hands,” Pfizer CEO Albert Bourla said in a video shared on Friday. “This is a historic day, a historic day for science and for all of us. It took just 248 days to get from the day we announced our plans to collaborate with BioNTech to our FDA submission day. “We have operated at extraordinary speed in our clinical development program, from concept to regulatory filing, while always maintaining our focus on safety.” The vaccine, known as BNT162b2, could potentially be available for use in high-risk populations in the United States by the middle to end of December, Pfizer and BioNTech said in a statement earlier Friday. The vaccine requires two doses a few weeks apart, and protection is achieved 28 days after the first shot. The submission to the FDA is based on results from the Phase 3 clinical trial of Pfizer’s vaccine, which began in the United States on July 27 and enrolled more than 43,000 volunteers. The final analysis from the trial found the coronavirus vaccine was 95% effective in preventing infections, even in older adults, and caused no serious safety concerns, Pfizer and BioNTech said this week. The submission also includes safety data on about 100 children ages 12 to 15. About 42% of global participants and 30% of US participants in the Phase 3 study have racially and ethnically diverse backgrounds, the companies said in a news release, and 41% of global and 45% of US participants are ages 56 to 85. Emergency use authorization, or EUA, from the FDA is not the same as full approval. An EUA allows products to be used under particular circumstances before all the evidence is available for approval. For an EUA, the agency says it will determine whether a product’s “known and potential benefits outweigh its known and potential risks.” Pfizer’s application for EUA is “encouraging,” but the Infectious Diseases Society of America stressed in a statement on Friday that a transparent review of Pfizer’s data is still needed. “While encouraging data from the Pfizer/BioNTech COVID-19 vaccine trial indicate the welcome possibility of a critical new tool against the pandemic, a comprehensive, transparent review of data, including evidence that the vaccine has been studied in diverse populations, remains essential to ensure its safety, effectiveness and acceptance,” Dr. Barbara Alexander, president of IDSA, said in the statement. “If emergency use authorization is granted, clinical trials and data collection must continue. Measures that include wearing masks, frequent handwashing, maintaining physical distance and restricting the size of gatherings will remain crucial,” the statement said in part. “Finally, new federal funding must be provided for widespread, fair and equitable vaccine distribution in addition to campaigns to build vaccine confidence.” What happens next The FDA said Friday it has scheduled a meeting of its outside advisory panel to discuss Pfizer and BioNTech’s application for emergency use authorization for a coronavirus vaccine for December 10. A source close to the process told CNN this week the Vaccines and Related Biological Products Advisory Committee could make a decision at the end of the meeting about whether to issue an EUA. Moderna, another pharmaceutical company, announced Monday that early clinical trial results show its vaccine is 94.5% effective, and it also plans to apply to the FDA for authorization after it accumulates more safety data later this month. “It will make sense that in all likelihood the FDA will consider both applications together,” the source said, considering that both the Pfizer and Moderna vaccines use the same technology and appear to have very similar safety and efficacy results from their large-scale clinical trials. “The FDA has been preparing for the review of EUAs for Covid-19 vaccines for several months and stands ready to do so as soon as an EUA request is submitted,” FDA Commissioner Dr. Stephen Hahn said in a statement Friday. “While we cannot predict how long the FDA’s review will take, the FDA will review the request as expeditiously as possible, while still doing so in a thorough and science-based manner, so that we can help make available a vaccine that the American people deserve as soon as possible.” If the FDA authorizes the vaccines, they can then be immediately distributed to states, according to a presentation made last month at the US Centers for Disease Control and Prevention. However, no one can be vaccinated until a CDC advisory committee reviews the data, recommends the vaccine, and decides which groups will receive it first. After authorization, the CDC’s Advisory Committee on Immunization Practices, an independent panel of experts, will meet within 24 to 48 hours, according to a CDC spokesperson. At that meeting, the committee will determine if everyone should get the vaccine, or if some people should be excluded. “We have all been alerted on ACIP we should be very flexible with our calendars because it’s likely there won’t be a lot of advanced notice given for this meeting. It will be done very, very quickly,” Dr. William Schaffner, a committee member, told CNN this week. Once ACIP issues its recommendations, vaccinations can be given. “We have a plan in place that the moment that the FDA concludes that that vaccine is safe and effective, we have a system in place to begin, within 24 hours, shipping that vaccine to hospitals, health care facilities and 24 hours after that, literally injecting that vaccine into Americans,” Vice President Mike Pence said during a White House Coronavirus Task Force briefing on Thursday. States are currently working out the details of running vaccination clinics. The Pfizer vaccine is particularly complicated, since it must be stored at minus 75 degrees Celsius, and doctors’ offices and pharmacies typically do not have freezers that go that low. The first groups expected to receive the vaccine are health care workers, the elderly, essential works such as police officers, and those with underlying medical conditions.