(074) Safety of COVID-19 Vaccines Among People With Prior History Of SARS-Cov-2 Infection: Results From the COVID-Vaccine-Monitor Cohort Event Monitoring

Publication Number: 411

Background: Safety of COVID-19 vaccines in people with prior SARS-CoV-2 infection has not been investigated in pivotal RCTs.

Objectives: We monitored COVID-19 vaccines' safety in those people through active surveillance and compare descriptive results with the general population.

Methods: In a prospective cohort of vaccinees with prior SARS-CoV-2 infection, we measured the frequency of local/systemic and serious adverse drug events (ADRs) following doses 1, 2 and booster of EMA-approved COVID-19 vaccines using data from the "Covid Vaccine Monitor” (CVM) study until December 2022. The results (without adjustments) were descriptively compared with those from the general population.

Results: 2,594 and 889 vaccinees with prior SARS-CoV-2 infection following the 1st and the booster dose, respectively, were enrolled. Most included vaccinees received Vaxzevria (37.1%) as a 1st dose and Comirnaty (57.5%) as a booster dose. Among 1st and 2nd dose recipients, 87.9% and 45.7%, respectively, experienced at least one ADR during a 6-month follow-up period. Injection site pain was the most frequently reported local ADR following both doses 1 (56.7%) and 2 (21.6%) of any vaccine. Systemically, fatigue (56.8% vs. 21.7%), headache (54.8% vs. 18.3%), myalgia (53.8% vs. 17.6%), and malaise (53.5% vs. 23.0%) were the most frequently reported. Similar findings were found after booster doses administration (injection site pain: 43.3%; fatigue: 39.3%; headache: 29.8%; myalgia: 28.3%; malaise: 28.0). Serious ADRs occurred in 0.2% and 0.1% of vaccinees following doses 1 and 2, respectively, and 0.1% following the booster dose. As for the general population (dose 1= 30,175; dose 2= 20,560), 67.7% and 49.1% reported at least one ADR following doses 1 and 2, respectively. The most commonly reported local/systemic ADRs following doses 1 and 2, across all vaccine brands, were injection site pain (36.2% vs. 21.9%), fatigue (35.7% vs. 23.2%), headache (33.1% vs. 17.9%), myalgia (32.9% vs. 18.5%) and malaise (30.9% vs. 19.0%). Serious ADRs were reported following doses 1 and 2, respectively, in 0.2% and 0.1% of vaccinees.

Conclusions: Descriptive analyses from this study showed high frequencies of local/systemic ADRs following dose 1 in vaccinees with prior COVID-19. Injection site pain, fatigue, headache, malaise and myalgia were the most frequently reported local/systemic ADRs, as for general population but with a lower frequency. Lower rates of local/systemic ADRs were reported following dose 2 of any vaccine. The reporting of ADRs for the booster dose was similar to that for dose 1. Higher percentages of local/systemic ADRs were observed following the booster as compared to dose 2 of any vaccine. Serious ADRs were very rare.