Booster shots are given after the protection provided by the original shot(s) has begun to diminish over time. As a result of the booster, people are able to maintain strong protection against severe Coronavirus infections. When eligible, everyone aged 5 and older should get a booster shot. An additional booster should be given to adults 50 and older and to children 12 and older who are moderately or severely immunocompromised. When it has been at least 28 days since your second dose of the Moderna or Pfizer COVID-19 vaccine, immunosuppressed individuals can get an additional dose. When it has been at least two months since you received the COVID-19 vaccine from Janssen/Johnson & Johnson, you can get an additional dose.