COVID-19 vaccine recommendations are based on your age, the vaccine you first received, and the time since your last dose. Children get a smaller dose of COVID-19 vaccine than teens and adults, based on their age group. Updated COVID-19 boosters can both help restore protection that has decreased since previous vaccination and provide broader protection against newer variants. The updated, or bivalent boosters, target the most recent Omicron subvariants, BA.4 and BA.5, that are more contagious and more resistant than earlier strains of Omicron.
For more details about vaccination schedules, go to the CDC's Stay Up to Date with COVID-19 Vaccines Including Boosters webpage.