[The stream is slated to start at 12 p.m. ET. Please refresh the page if you do not see a player above at that time.]A key Centers for Disease Control and Prevention advisory group is meeting Thursday to debate and vote on exactly who should get booster shots of Pfizer and BioNTech’s Covid-19 vaccine.The meeting comes a day after the Food and Drug Administration granted emergency use authorization to administer Pfizer’s shots to the elderly and adults with medical conditions that place them at risk of getting severely sick or who are at risk of serious complications because of frequent exposure to the virus.The agency also added people from 18 to 64 “whose frequent institutional or occupational exposure” to the virus place them at a high risk of getting Covid. That leaves enough room for the CDC panel to potentially recommend third doses for people in nursing homes, prisons, front-line health employees and other essential workers who were among the first Americans to get the initial shots in December.If the CDC adopts that plan Thursday, booster shots could begin immediately.