Formed as opsÅn- (the present stem of the Classical Latin obsÅnÅ, opsÅnÅ: “I purchase provisions", “I cater") + the English-ic; compare the contemporary Englishopsonin and the slightly later Frenchopsonique.
English Wiktionary. Available under CC-BY-SA license.
In this case a general reaction is stimulated by the vaccine which may aid in the destruction of the invading organisms. In regulating the administration of such vaccines he has introduced the method of observing the opsonic index, to which reference is made below.
In estimating the opsonic power of the serum in cases of disease a control with normal serum is made at the same time and under precisely the same conditions.
A particular bacterium had a special action in bringing about phagocytosis of that organism, and it had been found that this property was retained when the serum was heated at 55° C. It is now generally admitted that at least two distinct classes of substances are concerned in opsonic action, that thermostable immune opsonins are developed as a result of active immunization and these possess the specific properties of anti-substances in general, that is, act only on the corresponding bacterium.
The opsonic action of the serum has been employed by Sir A.
The object in such treatment is to raise the opsonic index of the serum, this being taken as an indication of increased immunity.