Along with eggs, I've used previously unopened sour cream WAY (, way) past the date and do the same as you once it's opened. Between the pasteurization of the original milk and then innoculation with good microbes, the lower moisture content and the acidity, it's not a very hospitable environment for pathogens.
Cauterization definition, to burn with a hot iron, electric current, fire, or a caustic, especially for curative purposes; treat with a cautery. See more. Dictionary.com
Immunization: the process by which a person becomes immune, or protected, against a disease. This term is often used interchangeably with vaccination or inoculation. However, the term vaccination is defined as the injection of a killed or weakened infectious organism in order to prevent the disease.