The vaccines produced by Oxford University in collaboration with AstraZeneca to protect against COVID-19 are safe and there is no evidence to suggest that the jabs are the cause behind blood clots as reported in some European countries, the British-Swedish pharmaceutical major and the UK's medicines regulator have said.
The interventions come as Germany, France and Italy joined the Netherlands as the latest countries to suspend the use of the Oxford/AstraZeneca vaccine, which also has a tie-up with the Serum Institute of India, after some reports of blood clotting.
It follows the Republic of Ireland, Bulgaria, Denmark, Norway and Iceland all pausing the administration of the vaccines as a precautionary measure after concerns raised around thrombotic events or clots.
“Around 17 million people in the EU and UK have now received our vaccine, and the number of cases of blood clots reported in this group is lower than the hundreds of cases that would be expected among the general population,” said Ann Taylor, Chief Medical Officer at AstraZeneca.
“The nature of the pandemic has led to increased attention in individual cases and we are going beyond the standard practices for safety monitoring of licensed medicines in reporting vaccine events, to ensure public safety,” she said.
The company said that safety is of “paramount importance” and the company is continually monitoring the safety of its vaccine.
“A careful review of all available safety data of more than 17 million people vaccinated in the European Union (EU) and UK with COVID-19 Vaccine AstraZeneca has shown no evidence of an increased risk of pulmonary embolism, deep vein thrombosis (DVT) or thrombocytopenia, in any defined age group, gender, batch or in any particular country,” it said.
Professor Andrew Pollard, director of the Oxford vaccine group that developed the jab, told the BBC that there was "very reassuring evidence that there is no increase in a blood clot phenomenon here in the UK, where most of the doses in Europe (have) been given so far".
So far across the EU and UK, there have been 15 events of DVT and 22 events of pulmonary embolism reported among those given the vaccine, based on the number of cases the company has received as of March 8.
This, it is said, is much lower than would be expected to occur naturally in a general population of this size and is similar across other licensed COVID-19 vaccines.
The stance has also been backed up by the World Health Organisation (WHO) and the UK's Medicines and Healthcare products Regulatory Agency (MHRA), with people being urged to carry on receiving their jabs.
WHO spokesperson Christian Lindmeier said: "As soon as WHO has gained a full understanding of these events, the findings and any unlikely changes to current recommendations will be immediately communicated to the public.
"As of today, there is no evidence that the incidents are caused by the vaccine and it is important that vaccination campaigns continue so that we can save lives and stem severe disease from the virus."
The reports are being closely reviewed but given the large number of doses administered, and the frequency at which blood clots can occur naturally, the evidence available does not suggest the vaccine is the cause, said Dr Phil Bryan, MHRA Vaccines Safety Lead.
“People should still go and get their COVID-19 vaccine when asked to do so,” he said.
He explained that blood clots can occur naturally and are not uncommon and that the reports of blood clots received so far are not greater than the number that would have occurred naturally in the vaccinated population.
“The safety of the public will always come first. We are keeping this issue under close review but available evidence does not confirm that the vaccine is the cause,” he added.
UK Prime Minister Boris Johnson reiterated when asked about vaccine safety: “In the MHRA we have one of the toughest and most experienced regulators in the world. They see no reason at all to discontinue the vaccination programme.”
The European Medical Association – which is also currently carrying out a review into incidents of blood clots – said the vaccine could continue to be administered.
More than 24 million people in the UK have now received the first dose of either the Pfizer/BioNTech or the Oxford/AstraZeneca vaccines currently being offered in age-wise cohorts by the National Health Service (NHS).
All adults over 56 and those in vulnerable medical categories are being encouraged to book their jabs to protect against the deadly virus.