Chapter 116. Immunization Principles and Vaccine Use (Part 8) potx

Chapter 116. Immunization Principles
and Vaccine Use
(Part 8)

Current recommendations also include influenza vaccine for routine annual
administration to individuals with chronic illness at any age, to persons living in
the same household as chronically ill individuals, and to all adults >50 years of
age. Polyvalent pneumococcal polysaccharide vaccine is similarly recommended
for adults ≥65 years of age and for all chronically ill persons. Hepatitis B vaccine
should be given to adults at high risk from clinical, occupational, behavioral, or
travel exposures, including patients undergoing hemodialysis, routine recipients of
clotting factors, health care workers exposed to potentially infected blood or blood
products, individuals living and working in institutions for the mentally
handicapped, travelers to highly endemic countries, persons at excess risk for
sexually transmitted diseases, injection drug users, and household contacts of
known carriers of hepatitis B surface antigen. Hepatitis A vaccine is recommended
for these same groups and for persons with clotting disorders or chronic liver
disease. There are a number of other special-use vaccines whose administration is
related to travel and occupational exposures (e.g., Japanese B encephalitis, typhoid
fever, yellow fever, and rabies); specific recommendations for the use of these
vaccines in the United States can be found at www.cdc.gov/nip/recs/adult-
schedule.htm.
Simultaneous Administration of Multiple Vaccines
There are no contraindications to the simultaneous administration of
multiple individual vaccines, although the use of licensed combination vaccines
can significantly reduce the required number of injections during the first 2 years
of life. Combination DTaP/Hib vaccine should not be used for primary
immunization of infants because it results in a blunted, suboptimal response to
Hib; the combination may be used for booster immunizations.
Simultaneous administration of the most widely used live and inactivated
vaccines has not resulted in impaired antibody responses or in elevated rates of

adverse reactions. In fact, this approach increases the likelihood that a child will
ultimately be fully immunized. The simultaneous administration of vaccines is
useful in any age group when the potential exists for exposure to multiple
infectious diseases during travel to endemic countries. Live-virus vaccines may be
given together on the same day; if this approach is not feasible, an interval of at
least 30 days should be allowed to avoid interference in the response to one or
another of the administered vaccine strains.
Because high doses of immune globulin can inhibit the efficacy of measles
and rubella vaccines, an interval of at least 3 months is recommended between the
administration of immune globulin and that of MMR vaccine or its components.
However, postpartum vaccination of rubella-susceptible women should not be
delayed because of the administration of anti-Rho(D) immune globulin or any
other blood product during the last trimester or at delivery. Should the
administration of an immune globulin preparation become necessary after
vaccination, it should be postponed, if at all possible, for at least 14 days to allow
time for vaccine-virus replication and development of immunity. In general, there
is little interaction of immune globulin with inactivated vaccines, and
postexposure passive prophylaxis can be given together with hepatitis B vaccine
or tetanus toxoid, resulting in both immediate and long-lasting protection.
Adverse Events
Vaccines are generally very safe. Serious adverse events proven to be due
to currently licensed vaccines are rare. Concerns about vaccine safety have at
times become inflated in conjunction with complacency about the consequences of
infections no longer routinely transmitted in the United States. As a result, some
parents have refused to have their infants and children immunized.
An adverse reaction or vaccine side effect is an untoward vaccine effect
that is extraneous to the vaccine's primary purpose (to produce immunity). An
adverse event can be either a true vaccine reaction or an event whose occurrence is
temporally related to a vaccine dose but is entirely unrelated to the vaccine itself.
As vaccines are routinely administered through childhood, coincidental events are

inevitable. Because our understanding of the underlying biologic mechanisms that
cause adverse events remains limited, a few highly publicized claims—
unsubstantiated by validated data or analysis—can easily heighten the suspicion
that some or all vaccines routinely cause unacceptable adverse events. Antivaccine
advocacy groups actively encourage the avoidance of immunization because they
believe that vaccines cause certain disorders (e.g., autism). This situation presents
a challenge to physicians and public health officials who must educate parents and
practitioners about vaccine benefits and risks.
It is true that modern vaccines, while remarkably safe and effective, are
associated with adverse events in some recipients and that these events range from
frequent and mild to rare and serious or even life-threatening. The decision to
recommend a vaccine involves an assessment of the risks of disease and its
complications for those who remain unimmunized and the benefit-to-risk ratio of
vaccination itself. Because these factors may change over time, the balance
between societal benefits and individual risks must be continually evaluated. Valid
and invalid contraindications to childhood immunization and appropriate
precautions in the use of specific vaccines are reported by the CDC (Table 116-3);
updated information can be found at www.cdc.gov/vaccines/recs/vac-
admin/downloads/contraindications_guide.pdf. A putative link between measles
immunization and autism has been the subject of intense international controversy.
The Institute of Medicine of the U.S. National Academies of Science has issued
four recent reports whose findings (1) fail to support hypotheses that vaccines are
associated with multiple sclerosis, neurodevelopmental disorders (e.g., autism), or
immune dysfunction; (2) provide no evidence for a temporal association of these
conditions with vaccination; and (3) elucidate no biologically plausible basis for
the purported relationships.