(275) Influenza Vaccine and Risk of Myocardial Infarction in The Korean Elderly

Sunday, August 28, 2022

8:00 AM – 1:45 PM CEST

Location: Hall C

Publication Number: 1320

Presenting Author(s)

EUNSUN LIM
– Seodaemun-gu, South Korea

Co-Author(s)

Heejin Kim
– Ewha Womans University, Seodaemungu, South Korea
Haerin Cho
– Ewha university, Seodaemun-gu, South Korea
Na-Young Jeong
– Ewha Womans University, Seodaemungu, Gyeonggido, South Korea
Joongyub Lee
– Department of Preventive Medicine, Seoul National University, Seoul, Republic of Korea
Yejee Kim
– Department of Clinical Epidemiology and Biostatistics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
Nam-Kyong Choi
– Department of Health Convergence, College of Science & Industry Convergence, Ewha Womans University, Seoul, Republic of Korea, Republic of Korea

Background: Seasonal influenza vaccination is recommended for the general population including the elderly. Recent prior studies suggested an association between the influenza vaccine and acute myocardial infarction (AMI).

Objectives: To determine the association between influenza vaccine and the risk of AMI in Korean elderly the 2017/2018 flu season.

Methods: We defined the 2017/2018 season were September 1, 2017, to April 30, 2018. The AMI patients identified who were diagnosed with AMI (ICD-10: I21) inpatients and received related procedure codes after influenza vaccination. We included patients in the 2017/2018 season who were over-aged 65 at the vaccination date. We excluded those who had a history of AMI-related disease (ICD-10: I21-I25) or persons who infected with influenza within 28 days of confirmed AMI. We performed the self-controlled case series (SCCS) design with a risk interval of 1 to 14 days and an observation period of 180 days postvaccination and calculated the incidence rate ratio (IRR). The IRR was calculated by comparing the risk of AMI in the risk interval versus the risk in the control interval within the observation period using conditional Poisson regression analysis.

Results: We identified 2,101 AMI events during the observation period. The number of events in the risk interval was 150 and the number of events in the control interval was 1,951. As a result, the incidence rate in the risk interval was 1.88 per 100,000 person-year, and in the control interval was 2.85 per 100,000 person-year. The IRR was 0.66 (95% CI: 0.56-0.78) in the interval 1-14 days following vaccination compared to the control interval.

Conclusions: This nationwide study found that influenza vaccination was associated with AMI benefits in the elderly. Therefore, our study indicates the safety of the influenza vaccine and the benefit of the national immunization program. However, Because our study is limited to only one flu season, further studies using subsequent flu seasons are necessary.