Yesterday the Centers for Disease Control and Prevention (CDC) updated its recommendations for Covid-19 immunizations.
Certain immunocompromised individuals and all people over the age of 50 who received either a Pfizer or Moderna booster at least four months ago are now eligible to receive another booster shot of either vaccine. Adults who have received a primary dose of the Johnson & Johnson vaccine, followed by booster at least four months ago, may now receive a second booster of either the Pfizer or Moderna vaccine.
Consult your doctor with any questions, especially if you believe you may qualify as immunocompromised but you are not sure.
For more information, see this link to the CDC statement.