Austria earlier reported it had suspended the use of a batch of AstraZeneca vaccines - batch number ABV5300 - after a person was diagnosed with multiple thrombosis and died 10 days after vaccination; another individual in that country was hospitalized with pulmonary embolism after being vaccinated, and is is now recovering, according to a European Medicines Agency (EMA) update on the matter.
Batch ABV5300 was delivered to 17 EU countries and comprises 1 million doses of the vaccine, as per data from that EU regulatory body.
Five other countries - Norway, Estonia, Latvia, Lithuania, and Luxembourg – have also suspended all or part of their AstraZeneca vaccine roll-out also as a precaution while they investigate thrombosis concerns.
The EMA said there is currently no indication that vaccination has caused these conditions, which are not listed as side effects with this vaccine. The most common side effects with COVID-19 Vaccine AstraZeneca, it added, are usually mild or moderate and improve within a few days after vaccination.
The agency’s Pharmacovigilance Risk Assessment Committee (PRAC) is reviewing all cases of thromboembolic events, and other conditions related to blood clots, reported post-vaccination with COVID-19 Vaccine AstraZeneca.
A spokesperson for AstraZeneca told BioPharma-Reporter: “Patient safety is the highest priority for AstraZeneca. Regulators have clear and stringent efficacy and safety standards for the approval of any new medicine, and that includes COVID-19 Vaccine AstraZeneca. The safety of the vaccine has been extensively studied in phase III clinical trials and peer-reviewed data confirms the vaccine is generally well tolerated.”
'Benefits outweigh risks'
“The position of EMA’s safety committee PRAC is that the vaccine’s benefits continue to outweigh its risks and the vaccine can continue to be administered while the investigation of cases of thromboembolic events is ongoing," said the EU regulator.
The number of thromboembolic events in vaccinated people is no higher than the number seen in the general population, it stressed. “As of March 10, 2021, it said there had been 30 cases of thromboembolic events reported among close to 5 million people vaccinated with COVID-19 Vaccine AstraZeneca in the European Economic Area.”
The review of thromboembolic events with COVID-19 Vaccine AstraZeneca is being carried out in the context of a safety signal, under an accelerated timetable, it added.
The agency said it will continue to communicate about findings as its assessment progresses.
The expert view
Prof Stephen Evans, professor of pharmacoepidemiology, London School of Hygiene & Tropical Medicine, commented on the suspension of the roll-out of the vaccine in those countries.
“This is a super-cautious approach based on some isolated reports in Europe. The problem with spontaneous reports of suspected adverse reactions to a vaccine are the enormous difficulty of distinguishing a causal effect from a coincidence.
“This is especially true when we know that COVID-19 disease is very strongly associated with blood clotting.
“The risk and benefit balance is still very much in favor of the vaccine in my view."
Dr Phil Bryan, vaccines safety lead the UK's Medicines and Healthcare products Regulatory Agency (MHRA), weighed in on the reports as well:
"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.
“Blood clots can occur naturally and are not uncommon. More than 11 million doses of the COVID-19 Vaccine AstraZeneca vaccine have now been administered across the UK. Reports of blood clots received so far are not greater than the number that would have occurred naturally in the vaccinated population."