Safety profile of inactivated COVID-19 vaccine in indonesian adults.

Background: Vaccines are urgently needed to handle the morbidity and mortality of the COVID-19 pandemic in Indonesia. The inactivated vaccine is widely used in Indonesia's national immunization program due to its eligibility of stock, easier to transport, and considered to be more established than newer platforms. In this study, we aimed to evaluate the safety profile of the inactivated vaccine and analyze the safety profile between adults and the elderly.

Methods: A prospective analytical study was conducted to evaluate the safety profile of inactivated COVID-19 vaccine among healthy adults aged ≥ 18 years from September 2nd to December 28th, 2021, at ten primary health centers from 5 districts in Jakarta, Indonesia. The participants were instructed to record the symptoms after inactivated COVID-19 vaccine injection in the diary card for 28 days. Chi-square tests were carried out to analyze the relationship between the adverse event following immunization (AEFI) in adults and elderly groups.

Results: Four of 1113 participants were not included in this study due to the lack of follow-up. Out of 1109 participants, there were 1044 adults (18-59 years) and 65 elderly (>59 years). There were no serious AEFI cases reported. Most AEFI cases were mild to moderate and resolved after several days of injection. Local pain, myalgia and fatigue were the most frequent adverse events reported. We found that there was no correlation between the adults and elderly age group with the incidence of AEFI (p = 0.924) for local reactions (p = 0.181) and most of the systemic reactions (p = 0.629). However, there is an increased risk of fever in the elderly group compared to the adult group (OR 4.046, 95 % CI 1.794-9.124, p = 0.003) following immunization.

Conclusions: Our study demonstrated that the inactivated COVID-19 vaccine is safe, considering that all symptoms experienced were mild to moderate and resolved entirely.