Whereas S-QIIV vaccination did not lead to significantly higher cumulative AF versus PBS at any time point within any gene, Wyeth/IL-15/5Flu–vaccinated mice accumulated mutations over time when comparing between day 3 and day 7 samples, significantly increasing their mutational load in four of eight genes: HA, NP, PA, and PB2. The gene discussed is IL15; the disease is atrial fibrillation.