A new study from the Center for Disease Control and Prevention confirms what Mayo Clinic and other experts have been saying: COVID-19 booster vaccinations improve protection against severe illness and hospitalization. The study examined people who had three doses of the Moderna or Pfizer COVID-19 vaccines, as well as whether it was a booster dose or the No. 3 dose for people who are immunocompromised. "The third dose actually decreased COVID-19-associated hospitalizations significantly ― more than the two doses alone," says Dr. Abinash Virk, a Mayo Clinic infectious diseases specialist. Dr. Virk says much has been learned about the effectiveness...