Multimorbidity and Its Effect on Self-Reported Adverse Effects Following COVID-19 Vaccination.

Introduction The coronavirus disease 2019 (COVID-19) vaccination has been suggested for those with comorbidities, although there are concerns regarding the vaccine's safety. This study aimed to compare the severity and incidence of post-vaccination side effects in people with and without comorbidities. Another aim of this study was also to look for the effect of multimorbidity on adverse events. Methods This observational study was conducted from November 2021 to February 2022. Data were collected from all over Pakistan using a self-administered online questionnaire that inquired about the subject's demographic, clinical, and COVID-19 vaccination profiles. Data analysis was done by using SPSS software version 22.0. (Chicago, IL, IBM Corp.). Results A total of 421 participants were included in the study, and 31.4% of individuals had underlying comorbidity. The overall mean age was 33 years (range: 13-85 years). This study included recipients of all major types of COVID-19 vaccines being used in Pakistan. Only 67.4% of the subjects had only underlying comorbidity, and hypertension was the most common one out of all comorbidities. Participants with comorbidities were not at a greater risk to produce vaccine-related adverse events when compared to those with no comorbidities. Comorbidity was also found to be statistically non-significant to the severity of the side effects. Only one subject with comorbidity produced a side effect and required hospitalization. Multimorbidity was not associated with a greater incidence of side effects. Multimorbidity was not significantly linked with the severity of the adverse effects, except muscle pain (p<0.05) and breathlessness (p<0.05). Conclusion It can be concluded that comorbidities do not affect the COVID-19 vaccine's reactogenicity but studies on an extensive scale should be conducted regarding individuals with multiple pre-existing comorbidities.