According to the CDC, as of October 21, 2021, individuals who received a Pfizer-BioNTech or Moderna COVID-19 vaccine, the following groups are eligible for a booster shot at 6 months or more after their initial series: (1) 65 years and older, (2) Age 18+ who live in long-term care settings, (3) Age 18+ who have underlying medical conditions, and (4) Age 18+ who work or live in high-risk settings. For the nearly 15 million people who got the Johnson & Johnson COVID-19 vaccine, booster shots are also recommended for those who are 18 and older and who were vaccinated two or more months ago.