Denmark became the first country to drop the Johnson & Johnson Covid-19 shot from its vaccination programme owing to blood clot concerns, weeks after also excluding the Oxford/AstraZeneca jab.

The Danish health authority said on Monday it had concluded that the benefits of the J&J vaccine did not outweigh its risks given that the country had the pandemic “under control” and had decent supplies of other jabs.

Deputy director-general Helene Probst said that Denmark would in the coming weeks be mostly vaccinating “younger and healthy people” and that the risk of causing severe blood clots weighed heavier than what it would lose from not using the jab to fight the spread of Covid.

“In the midst of an epidemic, this has been a difficult decision to make, especially since we have also had to discontinue using the Covid-19 vaccine from AstraZeneca,” she added.

Denmark is one of the European countries that has come furthest with reopening its society after Covid thanks to its “coronapas”, a certificate that states whether somebody has been vaccinated, had a recent negative test, or recovered from coronavirus in the past six months.

The government removed the AstraZeneca jab from its vaccine programme owing to a rare, unusual set of symptoms — including blood clots, bleeding, and low levels of platelets — identified in some people who had received the shot. The first death of somebody with such symptoms — a 60-year-old woman — was reported in Denmark in early March. US authorities have since said that some people using the J&J vaccine, which has never been used in Denmark, had similar symptoms.

Denmark has almost offered everybody aged 65-74 a first dose of a vaccine and will soon start vaccinating those younger than that. The Danish health authority said the decision to drop J&J would particularly affect those aged 20-39, who now face a delay of up to four weeks, meaning everyone would be fully vaccinated by late August.

Denmark’s prime minister Mette Frederiksen had previously hailed the J&J jab as a “potential game-changer” as the vaccine requires only one dose, whereas the jabs developed by BioNTech/Pfizer, Moderna and AstraZeneca all require two shots.

The decision underscores how EU countries are increasingly turning towards the Pfizer and Moderna shot, which are both mRNA-based vaccines. Most EU nations have restarted use of the AstraZeneca shot but many have age restrictions, such as Sweden and Finland, which are only using it for over 65s.

An expert commission in Norway will report by next Monday on how the country should use the AstraZeneca and J&J vaccines. Health authorities there recommended dropping AstraZeneca as Denmark had done, but the government was worried about its implications for J&J, which it had originally foreseen as using to vaccinate most people aged 18-45.

J&J said that two weeks ago, the EU’s medicine advisory committee had “confirmed the overall benefit-risk profile of the vaccine remains positive”.

“We believe a single-shot, easily transportable Covid-19 vaccine with demonstrated protection against multiple variants can help protect the health and safety of people everywhere,” the company added.

Additional reporting from Nikou Asgari in New York