Joseph Lewnard is an associate professor of Epidemiology at the School of Public Health at the UC Berkeley. He studies the transmission dynamics of infectious disease agents and the effectiveness of interventions such as vaccination. He uses mathematical and statistical modeling and collaborates closely with investigators leading field studies and disease surveillance. Much of his work centers around the impact of pneumococcal conjugate vaccines against disease caused by Streptococcus pneumoniae in both high- and low-income settings. Additional projects address the impact of existing pediatric vaccines, and those in development, against antibiotic use and resistance.