AstraZeneca said in a statement on Friday that it had no evidence that its vaccine against the novel Coronavirus had led to an aggravated risk of blood clots.
The statement by the British pharmaceutical group came in reaction to a move by various countries to suspend the use of its vaccine as a precautionary measure.
“An analysis of our safety data of more than 10 million records has shown no evidence of an increased risk of pulmonary embolism or deep vein thrombosis in any defined age group, gender, batch or in any particular country,” AstraZeneca said.
“In fact, the observed number of these types of events are significantly lower in those vaccinated than what would be expected among the general population,” it added.
Denmark, Iceland and Norway announced on Thursday that they were suspending the use of the AstraZeneca vaccine as a precaution. Bulgaria followed suit on Friday, while Thailand has delayed its campaign.
On Friday, the World Health Organisation (WHO) said it had no reason not to use the vaccine. A WHO spokeswoman said the Organisation’s experts were studying the information on blood clotting but stressed that so far no link had been found.
She recalled that, as at 9 March, over 268 million doses of anti-COVID vaccines had been administered worldwide since the start of the pandemic – based on figures obtained by the WHO from the authorities in each country – and that no deaths had been linked to the vaccines thus far.
The AstraZeneca and Pfizer-BioNTech vaccines are the only ones certified by the WHO.
The European Medicines Agency’s safety committee said on Thursday evening that “the vaccine’s benefits continue to outweigh its risks and the vaccine can continue to be administered” while an investigation into cases of thromboembolism was being conducted.
Earlier in the day, Denmark’s national health agency, the first to announce a suspension of the use of the vaccine, said it was doing so as a precaution following severe cases of clotting in vaccinated persons even though no link had been established between the clots and the vaccine.
Early this week, Austria stopped administering a batch of vaccines following the death of a 49-year-old nurse from severe coagulation disorders a few days after being vaccinated.