Vaxzevria Vaccine (AstraZeneca) Lists Additional Side Effects
The European Medicines Agency (EMA) announced today its safety committee (PRAC) concluded 'that unusual blood clots with low blood platelets should be listed as very rare side effects of Vaxzevria (formerly COVID-19 Vaccine AstraZeneca).
The PRAC noted that the blood clots occurred in veins in the brain (cerebral venous sinus thrombosis) and the abdomen (splanchnic vein thrombosis) and in arteries, together with low levels of blood platelets and sometimes bleeding.
Furthermore, the 'EMA confirmed the overall benefit-risk of Vaxzevira vaccination remains positive.'
In reaching its conclusion on April 7, 2021, the PRAC considered all currently available evidence, including the advice from an ad hoc expert group.
The EMA reminds healthcare professionals and people receiving the vaccine to remain aware of the possibility of very rare cases of blood clots combined with low levels of blood platelets occurring within 2 weeks of vaccination. So far, most of the cases reported have occurred in women under 60 years of age within 2 weeks of vaccination. Based on the currently available evidence, specific risk factors have not been confirmed.
People who have received the Vaxzevria vaccine should seek medical assistance immediately if they develop symptoms of this combination of blood clots and low blood platelets.
According to the EMA, one plausible explanation for the combination of blood clots and low blood platelets is an immune response, leading to a condition similar to one sometimes seen in patients treated with heparin (heparin-induced thrombocytopenia, HIT). The PRAC has requested new studies and amendments to ongoing ones to provide more information and take any further actions.