Each vial can contain as much as 2.2ml of vaccine, and each vaccine requires just 0.3ml, which means that if there has been no spillage during the filling of a vial, it can contain 2.1ml, enough for seven doses.
Jonas Egebart, Deputy Medical Director at North Zealand Hospital, reported the good news over Twitter on Sunday.
“Good vaccine news: In most cases we get seven doses drawn from one vial. That is up to 40 percent more than the five doses we originally expected,” he wrote.
The Danish Health Authority recommends that doctors and nurses use any extra doses they can get out of the vials they receive.
Leif Heiselberg, 79, a resident at an elderly care home in Odense on the island of Funen, was the first person in Denmark to receive the vaccine on Sunday morning.
Henrik Ullum, the director of Denmark's infectious diseases agency, said on Monday that no one had yet suffered any complications after being vaccinated.
“It all well according to plan. We sent 9,750 vaccines out to all five regions, and we have not received any feedback that there have been problems with logistics or of side effects, so it has gone well,” he told the Ritzau news agency.
On Monday evening, an additional 38,000 vaccine doses will be delivered to Denmark ahead of the full scale start of vaccinations on Tuesday.
“We are basically continuing the work that got off to a good start yesterday,” Ullum said. “Initially, we will continue [concentrating on] nursing homes and with frontline staff in the hospitals, and gradually we will expand further.
“But in the first instance, it is the elderly and vulnerable and health professionals who will get the upcoming doses.”
The Pfizer-BioNTech vaccine requires recipients to be given two doses, with a three week interval. The second round of vaccinations, after which recipients will have immunity against coronavirus, will be given from January 17th.