(049) The role of comorbidities in the development of AEFI after COVID-19 vaccination in a large prospective cohort with patient-reported outcomes in the Netherlands

Publication Number: 386

Background: The safety and effectiveness of COVID-19 vaccines in people with comorbidities have been investigated in clinical trials only to some extent. For this reason, there was limited information on the occurrence of adverse events following immunization (AEFIs) on all subpopulation levels at the time of marketing approval and the role of comorbidities as a possible risk factor for the development of AEFIs remained a topic for further study.

Objectives: This study aims to assess the association between pre-existing comorbidities and the incidence of AEFIs after COVID-19 vaccination in the Netherlands.

Methods: We assessed data from a prospective observational cohort study with patient-reported outcomes, in which people were followed for six months after their first COVID-19 vaccination. Separate analyses were done for the incidence of AEFIs after the first and second dose (excluding the Janssen [Johnson & Johnson] vaccine). The association between pre-existing comorbidities and the occurrence of AEFIs after COVID-19 vaccination was assessed for 10 comorbidities by performing logistic regression. Five different outcomes were investigated in a multivariate logistic regression by calculating odds ratios (ORs) with their corresponding 95% confidence interval (CI): the occurrence of any AEFI, injection site reactions, fatigue, malaise, and headache. The covariates included in the models were sex, age group, vaccine brand (AstraZeneca, Janssen, Moderna, and Pfizer), confirmed SARS-CoV2 infection prior to the first dose of vaccination and body mass index (BMI).

Results: A total of 30,970 participants completed the baseline questionnaire of which 42.1% reported at least one pre-existing comorbidity. Multivariable logistic regression results revealed significant positive associations between the incidence of AEFIs and the presence of various comorbidities after the first and/or second dose, including cardiac, muscular, endocrine and nervous system disorders. For participants with a psychiatric disorder, increased odds of an AEFI were observed for both the first dose and second dose (OR first dose: 1.67; 95%CI 1.24-2.95, OR second dose: 1.53; 95%CI 1.18-2.00).

Conclusions: The results showed that various comorbidities may be associated with the occurrence of an AEFI after receiving a COVID-19 vaccination. For participants with a psychiatric comorbidity this was observed after both the first and second dose. Our findings contribute to the knowledge gain about the response to vaccination in subpopulations with different comorbidities, part of which might interfere with the immune function. More research is needed to further scrutiny our findings.