Vaccination with Vaxzevria (AstraZeneca)
Last update 19.04.2021
Vaxzevria (AstraZeneca) is a vaccine against the coronavirus disease (Covid-19) that was discovered in 2019. The vaccine does not contain the virus itself and cannot cause Covid-19 disease. The pooled results from four clinical trials in the United Kingdom, Brazil and South Africa demonstrate that Vaxzevria (AstraZeneca) is a safe and effective way to prevent Covid-19 for people from 18 years of age.
The Pharmacovigilance Risk Assessment Committee (PRAC) of the European Medicines Agency (EMA) has assessed the reported cases of blood clots in people receiving the Vaxzevria (AstraZeneca) Covid-19 vaccine. The EMA has concluded that:
- the combination of blood clots and low platelet counts is extremely rare, and the overall benefits of the vaccine in preventing Covid-19 infection outweigh the potential risk of adverse reactions (the Covid-19 infection itself can lead to potentially fatal blood clots);
- the most likely explanation for the formation of very rare, unusual blood clots is an immune response that leads to a condition similar to that sometimes seen in patients treated with heparin (heparin-induced thrombocytopenia, HIT);
- based on the currently available evidence, no specific age, gender, or disease risk factors have been confirmed for the development of this very rare adverse reaction;
- there is no evidence of a problem related to specific batches of the vaccine or to particular manufacturing sites.
At present, no fatal cases have been confirmed in Latvia that have a causal relationship with the vaccine.
Information for patients
If you get any of the following symptoms after receiving the Covid-19 Vaxzevria (AstraZeneca) vaccine:
- pain in the chest or stomach;
- swelling or soreness in legs;
- severe or worsening headache or blurred vision after vaccination;
- persistent bleeding;
- multiple small bruises, reddish or purplish spots, or blood blisters under the skin.
Please seek prompt medical assistance and mention your recent vaccination!
Information for healthcare professionals
- Cases of thrombosis and thrombocytopenia, some presenting as mesenteric vein or cerebral vein thrombosis, including cerebral venous sinus thrombosis, have been reported in persons who had recently received the Covid-19 Vaxzevria (AstraZeneca) vaccine, mostly occurring within 14 days of vaccination. The majority of reports involved women under 55, although some of this may reflect the greater exposure of such individuals due to targeting of particular populations for vaccine campaigns in different Member States.
- The number of reported events exceeds those expected, and causality although not confirmed, cannot therefore be excluded. However, given the rarity of the events, and the difficulty of establishing baseline incidence since Covid-19 itself is resulting in hospitalisations with thromboembolic complications, the strength of any association is uncertain.
- The EMA considers that the benefits of the medicine still outweigh the risks, and there is no association with thromboembolic disorders overall. However, steps will be taken to update the SmPC and package leaflet with information on cases of disseminated intravascular coagulation (DIC) and CVST.
- Healthcare professionals are urged to be alert for possible cases of thromboembolism, DIC or CVST occurring in vaccinated individuals.
- Recipients should be warned to seek immediate medical attention for symptoms of thromboembolism, and especially signs of thrombocytopenia and cerebral blood clots such as easy bruising or bleeding, and persistent or severe headache, particularly beyond 3 days after vaccination.