By contrast, an "immune" is a person who has a high degree of resistance to the
organism and who, when exposed, does not develop the disease.
Immunity may be defined as the ability of an individual to resist or overcome the
invasion of disease germs. Most persons are born with a high level of immunity against
certain disease germs, but this immunity is only temporary and is lost within a few
months after birth. The immunity that adults possess usually is acquired after birth in
one of the following ways.
a. Natural Immunity. A person may acquire immunity to certain diseases, such
as measles, mumps, diphtheria, and chicken pox, by becoming infected with the germs
that cause them. Such an infection may result in a typical case or it may be so mild that
the disease is not recognized. In either instance, the body may build up resistance
enough to keep the individual from contracting the disease again. Many other diseases,
such as the common cold, pneumonia, and gonorrhea, do not induce effective or lasting
immunity and may be contracted repeatedly.
b. Artificial Immunity. In the case of some infectious which result in naturally
acquired immunity, it is possible to stimulate this products) into the person's body. This
process is called "vaccination" or "immunization." Usually, in order to obtain a
protecting level of immunity, it is necessary to give several doses of the vaccine at
successive intervals of a few weeks or few months. This is called the initial series.
Thereafter, because the immunity is gradually lost, it is necessary to have "booster"
doses at periodic intervals in order to restore and adequate level of resistance. At
present, effective artificial immunization is available against a limited number of
diseases, including smallpox, typhoid, tetanus, diphtheria, cholera, epidemic typhus,
plague, yellow fever, poliomyelitis, and some others. Artificial immunization does not
provide absolute protection against the specific disease nor does it protect against other
disease. Consequently, protective measures such as personal hygiene and sanitation
must never be relaxed because of a feeling of security that one has been "immunized."
1-18. COMMUNICABLE DISEASE CONTROL MEASURES
The Army is vitally concerned with keeping the solider mentally and physically fit.
His commander and his medical officer use every available means to make certain that
he is given the best health protection available. In this effort, all three factors involved in
the spread of communicable diseases are taken into consideration, namely, the source
of disease, the transmitting agency, and the susceptible person.