What type of testing can determine a person's immunity to a disease?

A blood titer test is specifically designed to assess a person's immunity to a certain disease by measuring the concentration of antibodies in the blood. When an individual is exposed to a virus or receives a vaccine, the immune system produces antibodies as a defense mechanism. The titer test quantifies these antibodies, indicating whether a person has sufficient immunity against a particular pathogen.

In contrast, a blood pressure test evaluates cardiovascular health, while a skin allergy test identifies allergic reactions rather than immune status against specific diseases. Vaccination is a preventive measure to stimulate immunity rather than a test to measure existing immunity. Thus, the blood titer test is the most suitable method for determining immunity to a disease.