Safety of ChAdOx1 nCoV-19 Vaccine: Independent Evidence from Two EU States

Abstract

Recent reports of thrombosis following AstraZeneca COVID-19 vaccine in young females (<55 years-old) led to temporary suspension and urgent investigation by the European Medicines Agency (EMA) that concluded that vaccine benefits still outweigh its side effects (SEs). Therefore, this study aims to provide early independent evidence on the vaccine SEs’ prevalence and their potential risk factors; a cross-sectional survey-based study was carried out between February and March 2021 in Germany and Czech Republic among healthcare workers who recently received the AstraZeneca COVID-19 vaccine. The study used a validated self-administered questionnaire composed of twenty-eight multiple-choice items covering demographic variables, medical anamneses, and local, systemic, oral, and skin related SEs of the vaccine. Out of the ninety-two included participants, 77.2% were females and 79.3% were from Germany. Their mean age was 35.37 ± 12.62 (19–64) years-old, 15.2% had chronic illnesses and 22.8% were receiving medical treatments. Overall, 94.6% of the participants reported at least one SE. The most common local SE was injection site pain (72.8%), and the most common systemic SEs were fatigue (73.9%), muscle pain (55.4%), chills (48.9%), feeling unwell (46.7%), nausea (45.7%), and headache (29.3%). The vast majority (91.9%) resolved within 1–3 days, and the below 35 years-old group was the least affected age group. The SEs’ frequency was insignificantly higher in females and previously infected participants; the vaccine safety for the elderly was supported by the early findings of this study. Chronic illnesses and medical treatments were not associated with an increased risk of SE incidence and frequency. No blood disorder SEs were reported in our sample. Further independent studies are highly required to evaluate the safety of the AstraZeneca vaccine and to explore whether gender or previous infection could be associated with the vaccine SEs.

Side Effects of mRNA-Based and Viral Vector-Based COVID-19 Vaccines among German Healthcare Workers

“…This is the first study to evaluate the side effects of COVID-19 vaccines among the German population to the best of the authors’ knowledge. This study is one of the few studies that aims to enhance our emerging knowledge about the risk factors of COVID-19 vaccines side effects by inquiring and analyzing the self-reported side effects across various demographic and medical parameters [ 20 , 21 , 22 , 30 , 31 , 40 , 62 ].…”

“…The formula of population survey studies was used to achieve 5% of error margin and 95% confidence level [ 19 ]. The expected frequency (outcome probability) is assumed to be 60% as the prevalence of side effects following COVID-19 vaccines ranged between 62% to 93% in our previous studies [ 20 , 21 , 22 ] ( Figure 1 ).…”

“…The items of the SAQ were stratified into four main categories: (a) demographic information including gender, age, profession, work experience, and federal state; (b) medical anamneses including chronic disease and medical treatments; (c) COVID-19-related anamnesis including previous infection, exposure, type of vaccine, number of doses; and (d) the local, systemic, oral, and skin-related side effects of COVID-19 vaccines [ 20 , 21 , 22 ].…”

Side Effects of mRNA-Based COVID-19 Vaccine: Nationwide Phase IV Study among Healthcare Workers in Slovakia

“…[33]. Expected Frequency: The overall prevalence of side effects following COVID-19 vaccines ranged between 62% and 93% [19,[67][68][69]. Acceptable Error Margin: 5% was assumed permissible because the expected frequency ranged between 10% and 90% [70].…”

Safety warning for ChAdOx1 nCov-19 vaccine in patients with sickle cell disease

“… 5 Recent data suggest that young patients are at increased risk of the Astra Zeneca COVID-19 vaccine. 6 It is also interesting to note that all three patients had S/B 0 thalassemia, and it is not clear if this has contributed to the development of these complications. In light of these findings, we have asked our patients to exercise caution when taking this type of vaccine.…”