What the latest news from Pfizer means for getting younger kids vaccinated. Plus, who will be able to get a booster shot and when. Read more:On Monday, Pfizer and BioNTech said that children ages 5 to 11 had a robust immune response to smaller doses of their coronavirus vaccine. Anita Patel, a critical-care pediatrician at Children’s National Hospital, explains what these results mean for slowing the spread of the coronavirus and what it has been like to take care of severely sick children during the pandemic. The Biden administration had promised that this would be the week anybody vaccinated on or before Jan. 20 would be able to get a booster shot. Health and science reporter Lena Sun explains the confusion around who is actually eligible for a booster and when people could get one.