Adverse Events Following COVID-19 Vaccination in Adolescents: Insights From Pharmacovigilance Study of VigiBase

BACKGROUND

During coronavirus disease 2019 (COVID-19) pandemic, several COVID-19 vaccines were licensed with fast-track procedures. Although these vaccines have demonstrated high immunogenicity, there has been concerns on the serious adverse events (AEs) following COVID-19 vaccination among adolescents. We aimed to analyze comparative safety of COVID-19 vaccination in adolescents.

METHODS

In this pharmacovigilance study, we performed a disproportionality analysis using VigiBase, the World Health Organization's global individual case safety report (ICSR) database. To compare serious AEs reported following COVID-19 vaccines vs. all other vaccines in adolescents aged 12-17 years, ICSRs following any vaccines on adolescents aged 12-17 years were included, defining cases as reports with the AEs of interest, with all other AEs as non-cases. The AEs of interest were myocarditis/pericarditis, multisystem inflammatory syndrome/Kawasaki disease (MIS/KD), anaphylaxis, Guillain-Barré syndrome (GBS), and immune thrombocytopenia (ITP). We conducted a disproportionality analysis to estimate reporting odds ratio (ROR) with 95% confidence interval (CI) for each AE of interest, adjusted for sex by using logistic regression.

RESULTS

Of 99,735 AE reports after vaccination in adolescents, 80,018 reports were from COVID-19 vaccinated adolescents (52.9% females; 56.3% America). The AEs of interest were predominantly reported as serious AE (76.1%) with mRNA vaccines (99.4%). Generally, higher reporting odds for the AEs were identified following COVID-19 vaccination in adolescents; myocarditis/pericarditis (2,829 reports for the COVID-19 vaccine vs. 35 for all other vaccines, adjusted ROR [aROR], 19.61; 95% CI, 14.05-27.39), and MIS/KD (104 vs. 6, aROR, 4.33; 95% CI, 1.89-9.88). The reporting odds for anaphylaxis (515 vs. 165, aROR, 0.86; 95% CI, 0.72-1.02), GBS (94 vs. 40, aROR, 0.64; 95% CI, 0.44-0.92) and ITP (52 vs. 12, aROR, 1.12; 95% CI, 0.59-2.09) were not significantly higher following COVID-19 vaccination.

CONCLUSION

In this study, there were disproportionate reporting of immune-related AEs following COVID-19 vaccination. While awaiting definitive evidence, there is a need to closely monitor for any signs of immune-related AEs following COVID-19 vaccination among adolescents.

Application of a patient-centered reverse translational systems-based approach to understand mechanisms of an adverse drug reaction of immune checkpoint inhibitors

Immunotherapy became a key pillar of cancer therapeutics with the approvals of ipilimumab, nivolumab, and pembrolizumab, which inhibit either cytotoxic T‐lymphocyte antigen‐4 (CTLA‐4) or programmed death‐1 (PD‐1) that are negative regulators of T‐cell activation. However, boosting T‐cell activation is often accompanied by autoimmunity, leading to adverse drug reactions (ADRs), including high grade 3–4 colitis and its severe complications whose prevalence may reach 14% for combination checkpoint inhibitors. In this research, we investigated how mechanistic differences between anti‐CTLA‐4 (ipilimumab) and anti‐PD‐1 (nivolumab and pembrolizumab) affect colitis, a general class toxicity. The data analytical platform Molecular Health Effect was utilized to map population ADR data from the US Food and Drug Administration (FDA) Adverse Event Reporting System to chemical and biological databases for hypothesis generation regarding the underlying molecular mechanisms causing colitis. Disproportionality analysis was used to assess the statistical relevance between adverse events of interest and molecular causation. We verified that the anti‐CTLA‐4 drug is associated with an approximately three‐fold higher proportional reporting ratio associated with colitis than those of the anti‐PD‐1 drugs. The signal of the molecular mechanisms, including signaling pathways of inflammatory cytokines, was statistically insignificant to test the hypothesis that the severer rate of colitis associated with ipilimumab would be due to a greater magnitude of T‐cell activation as a result of earlier response of the anti‐CTLA‐4 drug in the immune response. This patient‐centered systems‐based approach provides an exploratory process to better understand drug pair adverse events at pathway and target levels through reverse translation from postmarket surveillance safety reports.