All employees with whom Diess had personal contact were tested, and all were negative.
VW earlier this month expanded its in-house vaccination and testing program for employees and their relatives.
Since June, VW has administered about 100,000 doses — including first, second and booster shots — at sites in Germany.
Diess joins a list of corporate leaders forced to stay home because of the recent resurgence of the coronavirus.
Virgin Group founder Richard Branson caught the virus earlier this month, preventing the billionaire from ringing the opening bell at the Nasdaq exchange on which his Virgin Orbit satellite launch company was listed late last year.
Branson, 71, said he was vaccinated, and his symptoms were mild.
Reuters contributed to this report
