The Incidence of Influenza Among University Students After COVID-19 Vaccination at KSAU-HS in Saudi Arabia: A Questionnaire

Aims: This study investigated the incidence of seasonal influenza among university students following COVID-19 vaccination at King Saud bin Abdulaziz University for Health Sciences (KSAU-HS) in Riyadh, Saudi Arabia. The objective was to assess potential interactions between COVID-19 vaccination and influenza infection rates, particularly among students frequently engaged in close-contact activities. Methodology and Results: Data were collected through a self-administered questionnaire distributed to 230 students, capturing demographic details, vaccination status, preventive behaviors, and medical histories. Chi-square tests and logistic regression analyses were conducted to identify associations between these factors and influenza infection. The results indicated that 41.7% of participants reported contracting seasonal influenza, with males exhibiting significantly higher infection rates than females (p = 0.003). Preventive behaviors, particularly consistent mask-wearing, were associated with a lower infection rate (32.6%, p = 0.049). Although COVID-19 vaccination was not significantly associated with influenza risk overall (p = 0.141), the vaccine type influenced infection rates. Students vaccinated with Pfizer-BioNTech reported a higher incidence of influenza (47.4%) compared to those who received Moderna or Oxford-AstraZeneca (30.2%, p = 0.008). Additionally, prior household exposure to influenza was a significant risk factor, with infection rates reaching 50% (p = 0.002). Logistic regression analysis revealed that COVID-19 vaccination had a protective effect against influenza by reducing illness duration. Conclusion, Significance, and Impact of Study: This study highlighted potential interactions between COVID-19 vaccination and seasonal influenza, emphasizing the importance of preventive measures such as mask-wearing and infection control. Future research should incorporate clinical diagnostics and longitudinal studies to explore vaccine-specific effects and guide public health strategies addressing the coexistence of COVID-19 and influenza.