The European Medicines Agency (EMA) has amended product information for AstraZeneca’s (AZ) COVID-19 vaccine after concluding a preliminary review last week of cases of blood clots in people who had been vaccinated.
Following its review of the reported blood clots, the EMA’s safety committee, the Pharmacovigilance Risk Assessment Committee (PRAC), recommended that more details should be included in the vaccine’s product information that is made available for healthcare professionals and the public .
Last week the PRAC concluded that the benefits of the AZ’s Oxford University-partnered vaccine continue to outweigh the risk of side effects.
It also confirmed that the vaccine is not associated with an increase in the overall risk of blood clots, also referred to as thromboembolic events.
The committee did find, however, that the AZ/Oxford vaccine may be associated with very rare cases of blood clots associated with low levels of blood platelets (thrombocytopenia), including rare cases of clots in the vessels draining blood from the brain (CVST).
Due to its preliminary findings, the PRAC said it would complete an additional review of these risks, including considering the risks with other types of COVID-19 vaccines.
The EMA will continue to closely monitor safety reports concerning blood clotting, and will undertake further studies to provide additional laboratory data, in addition to real-world evidence.
The PRAC was ultimately ‘of the opinion’ that the AZ/Oxford’s efficacy in preventing COVID-19 hospitalisations and death outweighs the very rare likelihood of developing a blood clotting disorder.
In the EMA’s amended product information, it advises people who have had the vaccine to seek immediate medical attention if they develop shortness of breath, chest pain, leg swelling or persistent abdominal pain following vaccination.
It also advises people to seek medical attention if they experience a ‘few days’ of severe or persistent headaches or blurred vision after being vaccinated, or if they experience skin bruising or pinpoint round spots beyond the site of injection a few days after receiving the vaccine.
The EMA is convening an expert group meeting on 29 March to provide additional input into the PRAC’s ongoing assessment into the very rare blood clot cases.
This will include independent experts in haematology, cardiovascular medicine, infectious diseases, virology, neurology, immunology and epidemiology, who will present their views on the reported cases.
The outcome of this meeting, along with further analysis of the reported cases, will be included in the PRAC’s ongoing evaluation.
An updated recommendation on the issue is expected during the PRAC’s April plenary meeting.