Denmark has become the first country in Europe to abandon AstraZeneca's COVID vaccine.
The decision was taken due to the vaccine's link with very rare cases of blood clots, the country's health agency said.
Søren Brostrøm, director of the agency, said despite the World Health Organization and the European Medicines Agency (EMA) favouring the use of the AstraZeneca jab, Denmark's vaccine campaign would continue without it.
"Overall, we must say that the results show that there is a real and serious side effect signal in the vaccine from AstraZeneca," said Brostrøm in a statement.
"Based on an overall consideration, we have therefore chosen to continue the vaccination programme for all target groups without this vaccine."
In Denmark, two recipients of the AstraZeneca vaccine have suffered severe blood clots, one of which was fatal.
Nevertheless, most vaccinations have been with the Pfizer-BioNTech jab.
About 150,000 people have received the AstraZeneca vaccine and will now be offered a different jab for their second dose, said Brostrøm.
Despite the EMA's backing for the AstraZeneca vaccine in March, Denmark chose to continue its suspension of the jab while it investigated the blood clot reports. Today's move signals the country abandoning it altogether.
The majority of other European countries that suspended the vaccine have since resumed using it, often by confining jabs to a certain age group.
Neither the United States and Switzerland have authorised the use of AstraZeneca due to concerns over side effects.
The European Commission currently has a portfolio of 2.3 billion doses from several companies, including AstraZeneca and is negotiating more contracts.
AstraZeneca has experienced major delivery problems during the first quarter and expects to send far fewer vaccines than its contract with the EU called for during the second quarter.
EU Commission chief Ursula von der Leyen announced plans on Wednesday for a major contract extension for COVID-19 vaccines with Pfizer stretching to 2023, as well as 50 million Pfizer doses set to be delivered months ahead of schedule.