Patient-reported outcomes of adverse events after COVID-19 vaccination in Nigeria: A mixed methods study

Adverse events following immunization (AEFIs), especially if serious, may impact vaccine recipients' quality of life and financial well-being and fuel vaccine hesitancy. Nigeria rolled out COVID-19 vaccination in 2021 with little known about the impact of AEFIs on an individual's quality of life. No study in Africa has explored the health and financial impact of AEFIs. We explored patient-reported outcomes (PROs) of adverse events after COVID-19 vaccination and documented the lived experiences of those with serious AEFIs to understand the effect on their health, financial well-being, and attitude to future vaccinations.

We conducted a convergent mixed-methods study using the RAND 36-item health survey and in-depth interviews to collect PROs on vaccine recipients in Nigeria. Eight health scale scores and two summary composite scores were used to measure the health-related quality of life outcomes from the survey and inductive analysis was used to identify themes from the interview scripts. The results of both studies were integrated in a joint display to highlight areas of concordance.

In total, 785 survey responses were analyzed (53% females, 68% aged 18-30 years). Responders reporting an AEFI were 58%, of whom 62% received the first dose only. Younger age and first vaccine dose (p < .001 respectively) were associated with experiencing an AEFI. Not reporting an AEFI was associated with better quality of life, measured as higher scores on all eight SF-36 Health scales and the physical and mental component summary scores. All six interviewees with serious AEFIs experienced physical, mental, and financial distress. Some expressed a strong negative attitude toward future COVID-19 vaccinations but not toward vaccines for routine immunization.

AEFIs negatively impact the health and financial well-being of affected individuals and their attitude to future vaccinations, especially if serious. Understanding the impact of AEFIs on people is important and should inform future policies and interventions. The results of our study can inform policy and planning for future mass vaccination campaigns in LMICs.