The U.S. began giving out booster shots of the Pfizer COVID-19 vaccine on Friday, following the endorsement by the Centers for Disease Control and Prevention(CDC).

White House COVID-19 Response Coordinator Jeffrey Zients said during a press briefing held Friday that those eligible would be able to receive their third shot of the Pzifer vaccine from some 80-thousand places across the country, including over 40-thousand local pharmacies.

Earlier in the week, the CDC recommended booster shots for those at a higher risk, including adults 65 and older and those between the age of 50 to 64 with underlying health conditions.

CDC Director Rochelle Walensky later added adults over 18 with a high risk of exposure to the disease, including healthcare workers and teachers.

The shots will be available to those whose second Pfizer vaccine was administered at least six months ago.