This document provides methods and materials involved in making and using liquid vaccine preparations for oral administration. For example, methods and materials for making and using liquid vaccine preparations for oral administration that include a lyophilized or dried vaccine component (e.g., a lyophilized pathogenic agent such as a lyophilized rotavirus preparation) and a liquid edible oil composition (e.g., a liquid edible oil composition containing one or more medium chain triglycerides) are provided. In some cases, liquid vaccine preparations that include a buffer component (e.g., CaCO3) are provided.
