(P-322) Detecting Signals for the Vaccine-vaccine Interaction Between Pneumococcal Vaccines and Influenza Vaccines Using the Korea Adverse Event Reporting System (KAERS)

Background: Concomitant administration of pneumococcal and influenza vaccines is as effective as the separate vaccination with acceptable safety profiles. However, there is concern that concurrent vaccination may cause adverse events (AEs) induced by the vaccine-vaccine interaction.

Objectives: We aimed to identify the potential interactions between pneumococcal vaccines and influenza vaccines using the Korea Adverse Event Reporting System (KAERS).

Methods: We used the KAERS database from January 2015 to December 2019, analyzing AEs reported for vaccines, including pneumococcal polysaccharide vaccines (PPSV; WHO-ATC code, J07AL01), pneumococcal polysaccharide conjugate vaccines (PCV; J07AL02), and influenza vaccines (J07BB01- J07BB03). We applied the Ω shrinkage measure model and the chi-square statistics model to detect potential signals for interactions from the spontaneous reporting database. The former calculated the observed-to-expected ratio, suggesting Ω025>0 from the frequentist and the Bayesian perspectives as thresholds. The latter detected the potential signals for interaction when the measure ‘ꭓ’>2, which is the discrepancy between the observed and expected number of events with a specific drug. We compared the results with the drug label in Korea and databases such as Micromedex® and Uptodate.

Results: A total of 24,197 vaccine-related reports were included in the study. There is no signal that only detected by the Ω shrinkage model. Total fifteen signals and 23 signals were identified for PPSV-influenza and PCV-influenza interaction, respectively. Both Ω shrinkage measure models detected three of 15 PPSV signals and five of 23 PCV signals, including somnolence, gastroenteritis, granulocytopenia, infection bacterial, concussion, hypokinesia, insomnia, and chest pain. Most of the signals were not listed on the label and databases. Although granulocytopenia and concussion were noticed by all three indices, they were not recorded.

Conclusions: We identified the potential signals for the interaction when pneumococcal vaccines and influenza vaccines were administered concomitantly. In addition, we found the difference in detected signals of PPSV and PCV. Further investigations using other databases are needed to confirm our findings.