Dr. Natasha Halasa is a well-recognized leader in pediatric infectious diseases, focusing on epidemiology and vaccine research in multiple populations with studies that have led to practice changes. She has developed a robust diverse clinical research portfolio over the last two decades and has delivered numerous seminal lectures at national and international meetings reporting her findings. The primary focus of her research has been multiple complementary aspects covering acute respiratory and diarrheal infections. These are the two leading causes of death in children worldwide, so her findings have had significant global implications. Her work has included leading viral respiratory and diarrhea surveillance programs both locally and internationally, to define the fundamental epidemiology of these pathogens in children. She has defined pneumococcal disease burden in children before and after the introduction of pneumococcal conjugate vaccines so as to develop optimal policy recommendations. She is leading and multiple vaccine clinical trials in specialized populations (e.g., young infants, immunocompromised individuals), as often those populations are overlooked yet have the greatest need for detailed study. Her early infant vaccine studies are foundational and are moving the field forward. Her success in these areas is evident by her frequent and numerous presentations at national and international meetings. A unique strengths is her ability to translate epidemiologic studies into interventional studies to prevent infectious diseases, primarily through vaccine trials. She has been recognized as an exemplary leader for her distinctive talents of building and sustaining clinical research teams, bringing diverse groups of investigators together to complement each other’s scientific expertise, training and including young mentees in her research programs, and successfully recruiting and retaining subjects in clinical trials and projects. She is the driving force behind these vaccine studies, the results from her upcoming trials will potentially impact influenza vaccine recommendations in the transplant populations.