COVID vaccines - therapeutic errors reported to the UK National Poisons Information Service (NPIS)

ABSTRACT

Objective: The first COVID-19 vaccine was administered in the UK on the 8 December 2020. Since then, the UK has authorised four vaccines for use against COVID-19 (Pfizer/BioNTech, Oxford/ AstraZeneca, Moderna and Janssen). Serious adverse effects, including fatalities, have been linked to COVID-19 vaccines [1]. We reviewed all enquiries to the UK National Poisons Information Service (NPIS) related to COVID-19 vaccines. Methods: We conducted a retrospective analysis of enquiries relating to COVID-19 vaccines to the NPIS from 1 March 2020 until 31 July 2021. Enquiries were identified from the UK Poisons Information Database (UKPID) and filtered to identify those relating specifically to COVID-19 vaccines. Results: The NPIS received 34 enquiries about COVID-19 vaccines during the study period (Oxford/AstraZeneca 13, 38.2%;Pfizer/ BioNTech 9, 26.5%;Moderna 1, 2.9%). Two enquiries were seeking information about two different vaccines (Pfizer/BioNTech and Oxford/AstraZeneca) and in nine enquiries the manufacturer was unknown. Of these enquiries, 29 (85.3%) were specifically patient-related while five (14.7%) were for information only and were excluded from further analysis. The majority of patientrelated enquiries were from NHS 111 (17, 58.6%) with the remaining from hospitals (6, 20.7%) or primary care (6, 20.7%). All enquiries were regarding adult patients;21 enquiries were regarding female patients (72.4%) with 8 regarding male patients (27.6%). The most common enquiries were regarding patients who had received three doses instead of 2 (7, 24.1%), dosing errors due to incorrect dilution/reconstitution of the vaccine (5, 17.2%), doses administered outside the recommended timeframe of 8-12 weeks (5, 17.2%), adverse reactions (4, 13.8%) and patients receiving 2 doses in the same day (4, 13.8%). Nineteen patients (65.5%) were asymptomatic at the time of the enquiry. Four patients had symptoms (13.8%) but these were all deemed to be minor. In 6 enquiries (20.7%) it was unknown if the patient had symptoms. No moderate or severe symptoms were recorded and there were no fatalities. Conclusion: Serious adverse effects have been rarely associated with COVID-19 vaccines [1]. Enquiries to the NPIS regarding COVID-19 vaccines were generally related to administration or dosing errors. Reassuringly, in this patient population, most patients had no symptoms or mild symptoms only.