There is no indication that the Oxford-AstraZeneca Covid-19 vaccine is linked to an increased risk of blood clots, the EU's medicines regulator says.
It said the number of cases in vaccinated people was no higher than in the general population, reports the BBC.
The statement came after a number of countries, including Italy, Denmark and Norway, suspended the use of the jab.
The suspension followed reports that a small number of people had developed clots after receiving the vaccine.
There were also reports that a 50-year-old man had died in Italy after developing deep vein thrombosis (DVT) following a dose of the jab.
"There is currently no indication that vaccination has caused these conditions, which are not listed as side effects with this vaccine," the European Medicines Agency (EMA) said on Thursday.
"The vaccine's benefits continue to outweigh its risks and the vaccine can continue to be administered while investigation of cases of thromboembolic events is ongoing," it added.
It said there had been 30 cases of "thromboembolic events" among the five million Europeans who have received the jab.
AstraZeneca said the drug's safety had been studied extensively in clinical trials. "Regulators have clear and stringent efficacy and safety standards for the approval of any new medicine," a spokesperson said.
In the UK, the Medicines and Healthcare products Regulatory Agency (MHRA) said there was no evidence the vaccine had caused problems, and people should still go and get vaccinated when asked to do so. "Blood clots can occur naturally and are not uncommon. More than 11 million doses of the Covid-19 AstraZeneca vaccine have now been administered across the UK," said Phil Bryan of the MHRA.
The decision to temporarily suspend the use of AstraZeneca's jab has come as a setback for a European vaccination campaign that has stuttered into life, partly due to delays in delivery of the drug.
However, there was a positive development on Thursday as the EMA approved the single-shot Johnson & Johnson (J&J) vaccine. "More safe and effective vaccines are coming to the market," EU Commission President Ursula von der Leyen tweeted, although some reports suggest that J&J vaccine shipments may not arrive until April.
It comes on the same day a study revealed that the US Novax vaccine is 96% effective in preventing the original strain of covid and 86% effective against the English strain. Novavax is hoping to file for approval in the UK during the second quarter of 2021, AFP news agency reports.