(b) Diphtheria toxoid, tetanus toxoid, and pertussis vaccine (DPT).
This combination of immunizing agents is a pediatric preparation for immunizing
children under seven years old. Immunization is accomplished by administering
intramuscular injections of 0.5 ml at 2, 4, 6, and 18 months. Another dose is given
between four and six years. Booster injections are given after the age of six years with
adult Td and are repeated every ten years. Oral poliomyelitis (trivalent) doses are given
at the same time as the first five doses of DPT. The use of pertussis vaccine has
generated a great deal of alarm because of an exaggerated fear of neurologic damage
to young patients. Pertussis vaccine is associated with a small percentage of serious
adverse reactions. Seizures and brain damage have been reported. However, the risk
of pertussis disease with its own serious side effects far outweighs the risk of vaccine-
associated illness. This has been demonstrated during pertussis outbreaks in England
and other countries. There are ways to minimize side effects, such as delaying doses
until after fever or seizures have stopped. Details are presented in the 6 April 1984
edition of the Morbidity and Mortality Weekly Report (MMWR).
(4) Reimmunization. In most of the processes of active artificial
immunization, several injections of the immunizing agents (antigens or immunogens)
are used. The body's response to initial contact with most antigens is rather slow,
requiring two to ten weeks to reach fully effective quantity of antibodies.
Reimmunization is necessary because the antibodies and the immunity of the individual
who has been immunized may decline to a very low level as the years pass. The body
cells respond much more quickly on reimmunization. For this reason, only a small,
single dose of the antigen, the booster dose, is needed to reestablish a high grade
b. Passive Artificial Immunity. Passive immunity is immunity resulting from
injections of ready-made antibodies. The person becomes immune by receiving the
antibodies passively; the person's tissues play no part in actively producing the
antibodies. The need for passive immunity occurs when a person has been exposed to
and is in danger of becoming ill with a disease of a very serious nature. There is no
time to wait for the person to develop an active immunity, either natural or artificial. The
person must have a supply of ready-made antibodies now. Measles immune globulin,
human rabies immune globulin (HRIG), and hepatitis immune globulin (HBIG) are
examples of passive immunizing agents.
(1) Measles immune globulin. German measles (Rubella) is rarely harmful
to a woman in childhood, but if it occurs in a pregnant woman during the first three
months of the pregnancy, it often causes severe damage to the fetus. Deformities or
defects are particularly likely to occur in the heart, ears, brain, and eyes. Women who
are not immune can receive passive immunity during the first three months of
pregnancy. Gamma globulin (antibodies) from the blood of immune persons is used.
The results are variable.