Use of the AstraZeneca COVID-19 (AZD1222) vaccine: updated Joint Committee on Vaccination and Immunisation (UK) statement.

Department of Health & SOcial Care (UK) Statement made on 7 May 2021:There have been reports of extremely rare adverse events of concurrent thrombosis (blood clots) and thrombocytopenia (low platelet count) following vaccination with the first dose of AstraZeneca ChAdOx1 nCoV-19 vaccine (AZD1222). There have been no safety concerns identified for thrombosis/thrombocytopenia associated with the second dose of the AstraZeneca (AZD1222) vaccine, nor with other COVID-19 vaccines currently approved for use in the UK (Pfizer-BioNTech and Moderna). On 7 April 2021, after considering the relative balance of benefits and risks, the Joint Committee on Vaccination and Immunisation (JCVI) advised that, for adults aged under 30 years without underlying health conditions that put them at higher risk of severe COVID-19 disease, there should be a preference for an alternative to the AstraZeneca (AZD1222) vaccine, if available. The available data suggests there is a slightly higher incidence (number of cases per million doses of vaccine given) reported in the younger compared to older adult age groups. There are currently no known risk factors for this extremely rare condition, which appears to be an idiosyncratic reaction on first exposure to the AstraZeneca (AZD1222) vaccine..