The Centers for Disease Control and Prevention approved a booster shot of the Pfizer (PFE) and BioNTech (BNTX) Covid-19 vaccine for Americans aged 65 and older, some adults with underlying medical conditions and some adults in high-risk working and institutional settings. The director of the CDC said that people 65 years and older and residents in long-term care settings should get a booster and and so should people 50 to 64 years old who have an underlying medical condition. The agency added that those 18 to 49 with underlying medical conditions, and those 18 to 64 who are at an increased risk because of an occupational or institutional setting may also get a booster. The CDC’s committee of advisers on Thursday voted against recommending a booster for people younger than 65 who have a high risk of being exposed to the virus at work, including health care workers and teachers. CDC Director Rochelle Walensky went against the vote.