The Kaaba is a cubic structure that is the focal point of Islam and draped in a gold-embroidered black cloth.
State media said that an army of 3,500 workers was tasked with sterilising the Grand Mosque ten times a day to prevent any spread of infection.
This year's hajj is being held at a time when new variants of the virus are causing global concern.
Saudi Arabia has recorded more than 510,000 cases of coronavirus including 8,089 deaths.