Relative immunity is a term used to describe the concept of immunity that is not absolute, but instead varies depending on the circumstances or type of disease involved. The spelling of the word 'relative' is pronounced as /ˈrɛlətɪv/ using the International Phonetic Alphabet (IPA). Meanwhile, 'immunity' is spelled as /ɪˈmjuːnɪti/. This term is commonly used in medical and scientific fields to describe a person's or population's level of immunity to a particular disease. It is important to understand this concept to properly assess the effectiveness of vaccines and other medical treatments.
Relative immunity refers to a state of reduced susceptibility or resistance to a particular disease or infection in an individual or a population. It is characterized by a level of protection that is stronger than that of the general population, but not absolute or complete immunity.
In the context of diseases and infections, relative immunity can be acquired through various means, such as previous exposure to a milder or similar strain of the pathogen, vaccination, or a combination of both. This acquired immunity enables the body's immune system to recognize and mount a more efficient response against the infectious agent, effectively reducing the severity of the disease or preventing its onset altogether.
The term "relative" emphasizes that while individuals with relative immunity may experience a reduced risk of falling ill, they are not entirely immune to the disease or infection. Factors influencing the degree of relative immunity can include the strength and duration of previous exposure, the quality of the immune response, and the stability and mutation rate of the pathogen itself.
Relative immunity can also be observed at a population level when a significant portion of the community has acquired immunity through vaccination or previous exposure. This results in fewer susceptible individuals in the population, limiting the spread of the infectious agent and providing indirect protection to those who are not immune. However, it is important to note that relative immunity does not confer invincibility, and individuals with relative immunity may still be at risk of reinfection or transmission in certain circumstances.
An i. which may be due to a reduction of avidity of the body cells for the specific poison, or to a deviation or loss of complement in the blood.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
The word "relative immunity" is composed of two main parts: "relative" and "immunity".
The term "relative" is derived from the Latin word "relativus", meaning "pertaining to something in relation to something else". It comes from the Latin verb "relare", which means "to carry back" or "to refer". Over time, "relative" in English has come to mean something that is compared or evaluated in relation to something else.
The term "immunity" originates from the Latin word "immunitas", which means "exemption" or "freedom from public service". It is derived from the Latin prefix "im-" (meaning "not" or "without") and "munus" (meaning "service" or "duty"). "Munus" is related to the word "munus" in Old English, which means "gift" or "service".