The man was brought before an Athens prosecutor and charged with theft and endangering public health.
According to the police, the 46-year-old man was delivering coffees to the Agia Paraskevi Health Center, in northern Athens.
Employees became alarmed when he kept asking a series of questions about the vaccine and how effective it is.
They later discovered that one of the vials containing five doses of the Pfizer vaccine was missing.
They alerted the police, who quickly arrested the man.
The stolen vaccine has not been located and is obviously damaged and unsuitable for use.
Million of vaccines administered as Greece steps up campaign
The incident occurred as Greece is stepping up vaccinations to be able to open up to foreign travel beginning in the middle of May.
Deputy Civil Protection Minister Nikos Hardalias said on Tuesday that Greece is aiming for more than four million vaccinations by the end of May, while predicting that the country will reach six million vaccinations by the end of June.
“(Authorities) are making a huge effort,” he said during a visit to a new vaccination center in Patra in the northern Peloponnese.
He said Greece has so far administered 2,252,569 doses of coronavirus vaccine to the populace.
Record number of intubations on Wednesday
Greece recorded its highest number of Covid-19 patients on ventilators Wednesday, with 809 people undergoing the intensive treatment.
This disturbing figure is seven more than the 802 patients undergoing the invasive treatment in the country yesterday, on Tuesday, which itself had set a new record for the country.
Greece recorded 3,089 cases of the coronavirus on Wednesday. Tragically, 81 people suffering from the coronavirus passed away in the country over the past 24-hour period.