ABSTRACT
Introduction: The large-scale immunization with COVID-19 vaccines has brought safety surveillance to unprecedented levels. This context provides a unique opportunity to study the impact of communication on the reporting of adverse events following immunization (AEFIs), also known as notoriety bias. Objective(s): To describe trends over time in the reporting of AEFIs with COVID-19 vaccines in the US and Canada following regulatory and major media communications, without implying causality. Method(s): Data sources were US VAERS and Canada Vigilance. Weekly reporting rates were estimated by vaccine type (mRNA vs. non-replicating viral vectors) using the number of doses administered in each country, and time trends were derived. Study period started on the date of availability of vaccines in each country until 24 December 2021 (VAERS) and 31 August 2021 (Canada Vigilance), last available updates. A rapid review was conducted to identify major communications on COVID-19 vaccine safety. The dates and contents of communications were compared to time trends in reporting rates, without making causal inferences. Result(s): In the US, the risk of thrombosis associated with viral vector vaccines was covered by 5 major communications [13 April 2021, 2 warnings, 20 April 2021, 30 April 2021, 16 December 2021], which was followed by an increase in reporting rate of thrombotic events of 529.6% within 1 week after the first communication. There were 2 communications on thrombosis in Canada (16 March 2021, 13 May 2021) as well as 1 warning on capillary leak syndrome (29 June 2021). In Canada Vigilance, an increase in reporting rate of 452.5% was found almost 3 weeks prior to the publication of the first communication, which coincides with the date of release of the communication in the US. There was 1 major communication on the risk of pericarditis and myocarditis associated with mRNA vaccines in the US (24 June 2021) where an increase in reporting rate of 33.6% was observed less than 1 week before the warning. There were 2 communications in Canada (both on 30 June 2021) where the reporting rate of pericarditis and myocarditis for mRNA vaccines increased by 47.8% within 1 week following the communications. Changes in reporting rates were not observed for AEFIs not covered in communications. Observed trends were the same for reports submitted by health care providers and consumers. Conclusion(s): The dramatic increase in reporting rate immediately after, or sometimes just before, the release of communications was likely due notoriety bias. There was no spillover effect to other AEFIs.
ABSTRACT
Introduction: The large-scale immunization with COVID-19 vaccines has brought safety surveillance to unprecedented levels. This context provides a unique opportunity to study the impact of communication on the reporting of adverse events following immunization (AEFIs), also known as notoriety bias. Objective: To describe trends over time in the reporting of AEFIs with COVID-19 vaccines in the US and Canada following regulatory and major media communications, without implying causality. Methods: Data sources were US VAERS and Canada Vigilance. Weekly reporting rates were estimated by vaccine type (mRNA vs. non-replicating viral vectors) using the number of doses administered in each country, and time trends were derived. Study period started on the date of availability of vaccines in each country until 24 December 2021 (VAERS) and 31 August 2021 (Canada Vigilance), last available updates. A rapid review was conducted to identify major communications on COVID-19 vaccine safety. The dates and contents of communications were compared to time trends in reporting rates, without making causal inferences. Results: In the US, the risk of thrombosis associated with viral vector vaccines was covered by 5 major communications [13 April 2021, 2 warnings, 20 April 2021, 30 April 2021, 16 December 2021], which was followed by an increase in reporting rate of thrombotic events of 529.6% within 1 week after the first communication. There were 2 communications on thrombosis in Canada (16 March 2021, 13 May 2021) as well as 1 warning on capillary leak syndrome (29 June 2021). In Canada Vigilance, an increase in reporting rate of 452.5% was found almost 3 weeks prior to the publication of the first communication, which coincides with the date of release of the communication in the US. There was 1 major communication on the risk of pericarditis and myocarditis associated with mRNA vaccines in the US (24 June 2021) where an increase in reporting rate of 33.6% was observed less than 1 week before the warning. There were 2 communications in Canada (both on 30 June 2021) where the reporting rate of pericarditis and myocarditis for mRNA vaccines increased by 47.8% within 1 week following the communications. Changes in reporting rates were not observed for AEFIs not covered in communications. Observed trends were the same for reports submitted by health care providers and consumers. Conclusion: The dramatic increase in reporting rate immediately after, or sometimes just before, the release of communications was likely due notoriety bias. There was no spillover effect to other AEFIs.
ABSTRACT
Objective: We evaluated mortality in patients with pemphigus compared with non-pemphigus individuals matched on age and gender, in the United States (US). Methods: This retrospective cohort study used data from the US Optum Clinformatics claims database between May 1, 2000 and December 31, 2020. Mortality was assessed during a follow-up of up to 4 years after the index date (first pemphigus diagnosis). A sensitivity analysis was conducted (end of study period, March 31, 2020) to exclude the potential impact of COVID-19 on mortality analysis. Multivariable models (comorbidities as adjustment variables) were used to assess hazard ratios (HRs). Propensity score matched (PSM) model was used to minimize comorbidities difference at baseline. Results: Overall, 1391 patients with pemphigus (ICD-9 and ICD-10 codes) were identified (mean [SD] age: 63.7 [17.9] years;females: 57.0%). During follow-up, 227 patients (16.3%) died in the pemphigus cohort, compared with 172 patients (12.4%) in the non-pemphigus cohort. Pemphigus patients had higher death rate than the non-pemphigus cohort (adjusted HR [95% CI]: 1.69 [1.37–2.09];unadjusted HR [95% CI]: 1.33 [1.09–1.63];PSM HR [95% CI]: 1.49 [1.19–1.86];P <.01 for all). Similar results were observed in the sensitivity analysis (adjusted HR [95% CI]: 1.77 [1.41–2.23];P <.01);PSM HR [95% CI]: 1.52 [1.20–1.93];P <.01]). Infections, hypertension, diabetes, hematologic abnormalities, and cardiovascular comorbidities were strongly associated with mortality in pemphigus patients. Conclusions: These results suggest that pemphigus is associated with increased mortality observed over 4 years, highlighting the need for better treatment options for these patients.