There have been several instances where predictions have successfully informed public health actions: 1. Influenza Forecasting: Seasonal flu forecasts have improved vaccination strategies and reduced the impact of annual flu outbreaks. 2. COVID-19 Projections: Predictive models played a crucial role in understanding the spread of COVID-19 and informing lockdown measures and vaccination rollouts. 3. Vector-Borne Diseases: Predictions of diseases like dengue and malaria have helped in implementing timely vector control measures.