The Public Health Agency of Canada (PHAC) is a federal agency responsible for public health functions including disease surveillance, health promotion, emergency preparedness, and managing responses to health threats. PHAC monitors infectious disease outbreaks, coordinates vaccination programs, issues travel health advisories, and works with provincial health authorities during emergencies. The agency gained significant prominence during the COVID-19 pandemic, coordinating national response efforts, providing guidance on public health measures, and overseeing vaccine procurement and distribution. PHAC also addresses chronic disease prevention, injury prevention, and health equity. The Chief Public Health Officer leads the agency and serves as chief health advisor to the federal government.