The pandemic of COVID-19 highlights the need for public health initiatives in ensuring population health. The spread of SARS-CoV-2 infections has been slowed by large-scale testing, contact tracing, social distancing, and mask usage. Precision medicine emphasizes more precise diagnosis and treatment based on a multiplicity of biomarkers, such as genetic variants, as well as data about the environment, lifestyle, and behaviors of patients. Individual vulnerability and responses to COVID-19 may be better understood using PM methods. PM methods, as they have proven for individuals taking medications like abacavir, may be useful for detecting risks of adverse treatment effects for patients with specific genetic variations, which can assist health-care providers decide whether to change dosages or avoid particular treatments for some people.