ABSTRACT
Background: Patients with high-risk cardiovascular disease (CVD) are more susceptible to influenza-related complications, which can exacerbate cardiovascular events. Influenza vaccination has been recommended as a preventive measure; however, its immunogenicity and clinical benefits in this population remain inadequately studied.
Aim: This study aimed to evaluate the immune response to the influenza vaccine in patients with high-risk CVD and assess its impact on protection against influenza-related complications and overall clinical outcomes.
Methods: This prospective study was conducted at Services Hospital Lahore from October 2023 to September 2024, involving 50 patients diagnosed with high-risk CVD. Participants received the seasonal influenza vaccine, and their immune response was assessed through serological markers, including hemagglutination inhibition (HAI) titers, measured pre- and post-vaccination. Clinical outcomes, including influenza incidence, hospitalization rates, and cardiovascular events over a 12-month follow-up period, were analyzed.
Results: The influenza vaccine elicited a significant immune response in the majority of participants, with a ≥4-fold increase in HAI titers observed in 72% of patients (p < 0.05). Vaccinated patients had a lower incidence of influenza-related complications, reduced hospitalizations, and fewer cardiovascular events compared to historical controls (p < 0.05). No severe vaccine-related adverse events were reported.
Conclusion: Influenza vaccination effectively stimulated an immune response in patients with high-risk CVD and was associated with reduced influenza-related morbidity and cardiovascular complications. These findings support routine influenza vaccination as a crucial preventive strategy in this population. Further studies with larger cohorts are warranted to confirm these results.
Keywords: Influenza Vaccine, Cardiovascular Disease, Immune Response, Hemagglutination Inhibition, Clinical Outcomes, Preventive Cardiology