The University of Iowa Hospitals and Clinics added Moderna and Johnson & Johnson (Janssen) COVID-19 vaccines to the booster program for UI Health Care faculty and staff on Friday.

On Friday, the Centers for Disease Control and Prevention approved the use of booster doses for Moderna and Johnson & Johnson, according to the Iowa Department of Public Health. Pfizer doses were approved last month, as previously reported by The Daily Iowan. Additionally, the CDC is allowing “mix and match” dosing for booster shots only.

As previously reported by the DI, alongside people aged 65 years and older, residents in long-term care facilities, and people aged 50 to 64 years with underlying health conditions, health care workers are in the first group that is eligible for booster shots, according to an announcement from the CDC.

Eligible faculty and staff who received their second dose of Pfizer-BioNTech or Moderna and their single dose from Johnson & Johnson at least six months ago will receive an email from University Employee Health Clinic to book their appointment, UIHC said in a release.

UIHC said a “booster dose” refers to another dose of a vaccine that is given to someone who built enough protection after vaccination, but then that protection decreased over time — waning immunity.

Employees should still get vaccinated, even if they’ve already contracted COVID-19 and recovered from it. The natural immunity people receive from the virus is enhanced by the vaccine, UIHC said.

It’s never too late to get the COVID-19 vaccine to protect yourself and others around you, UIHC said.