An antibody count that indicates immunity to a disease is called what?

An antibody count that indicates immunity to a disease is called what?

• A. Titer
• B. Antigen level
• C. Antibody index
• D. Immunity score

Answer: (A)

Measuring how much antibody is present in the blood to show protection relies on a titer. A titer is the highest dilution of a sample at which antibodies against a specific disease can still be detected. In practice, a higher titer means more antibodies and a stronger likelihood of immunity, while a low or undetectable titer suggests little protective antibody remains. This concept specifically captures the amount of antibody, not the amount of pathogen components. Other terms like antigen level look at the presence of the pathogen itself, while antibody index or immunity score aren’t standard measurements for establishing immune protection.

Measuring how much antibody is present in the blood to show protection relies on a titer. A titer is the highest dilution of a sample at which antibodies against a specific disease can still be detected. In practice, a higher titer means more antibodies and a stronger likelihood of immunity, while a low or undetectable titer suggests little protective antibody remains. This concept specifically captures the amount of antibody, not the amount of pathogen components. Other terms like antigen level look at the presence of the pathogen itself, while antibody index or immunity score aren’t standard measurements for establishing immune protection.