Denmark said Monday it would not include the Covid-19 vaccine from US drugmaker Johnson & Johnson in its national vaccination campaign, citing worries over serious side effects involving blood clots.

“The Danish Health Authority has concluded that the benefits of using the Covid-19 vaccine from Johnson & Johnson do not outweigh the risk of causing the possible adverse effect… in those who receive the vaccine,” the authority said in a statement.

“Therefore, the Danish Health Authority will continue the Danish mass vaccination programme against Covid-19 without the Covid-19 vaccine from Johnson & Johnson,” it added.

The move comes after the Nordic country last month stopped using AstraZeneca’s vaccine altogether over a potential link to a rare but serious form of blood clot.

The rollout of J&J’s vaccine has also been delayed elsewhere in Europe over similar clotting concerns, though the WHO and European Medicines Agency (EMA) have both authorised the vaccine.

The European medicines watchdog said its safety committee had concluded that a warning about unusual blood clots with low platelets must be added to the vaccine’s labels, just as was required of AstraZeneca. J&J said in a news release that it would comply with that measure.

Excluding the J&J vaccine, which accounts for around a third of Denmark’s total contracted supplies of Covid-19 shots, could significantly delay the country’s vaccination calendar.

(FRANCE 24 with AFP and REUTERS)