(1) Live organisms. Vaccines that consist of suspensions of attenuated
(weakened) live organisms -- bacteria or viruses:
Smallpox.
Poliomyelitis.
Yellow fever.
Measles.
Mumps.
Rubella.
Adenovirus.
A single injection of such a vaccine, properly prepared, stored, and used so that it
retains required viability (potency), usually provides a fairly rapid, ample, and lasting
immune response.
(2) Inactivated (killed) organisms. Vaccines made from inactivated
organisms include:
Influenza.
Typhoid fever.
Cholera.
Plague.
Meningococcal.
Rabies.
A single injection of most inactivated vaccines may produce only a scarcely detectable
response.
The first injection orients the body so that subsequent injections
produce successively larger responses.
It is for these reasons that immunization against typhoid fever, cholera, typhus, tetanus,
and other diseases for which nonliving vaccines are utilized is carried out by a series of
injections.
(3) Products of organisms. Toxoids consist of chemically inactivated
bacterial poisons injected into individuals to induce the formation of antibodies against
the original bacterial toxin. The two commonly used toxoids are tetanus and diphtheria
toxoids.
b. Passive Immunity. Passive immunity depends upon the presence of
injected, preformed antibodies. The source of such antibodies is serum globulin, a
concentrated fraction of blood plasma from human beings. Immune serum globulin
(gamma globulin) contains the dominant form of antibodies found in the blood of normal
adult human beings. In practice, it has been found to be of value as a prophylaxis
against hepatitis, measles, and, in a marginal sense, of poliomyelitis. Immune globulin
MD0152
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