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General Considerations
Immunobiologic agents for adults contain antigens
(vaccines, toxoids) or antibodies (immune globulins, antitoxins).
- A toxoid is a
modified bacterial toxin that has been rendered nontoxic but retains
the ability to stimulate the formation of antibodies.
- A vaccine - a
suspension of whole (live or inactivated) or fractionated bacteria or
viruses that have been rendered nonpathogenic - is given to induce an
immune response and prevent disease. Although the development and
widespread use of vaccines is a major public health triumph, vaccines
pose risks as well as benefits. Even though no vaccine is entirely
safe or completely effective, their use as described is strongly
supported by their benefit-to-risk ratio.
Vaccines should always be given exactly as
recommended on the package insert; however, the interval between a
series of doses may be lengthened without losing efficacy.
Non-Rutine immunization also
include:
- Immunizations for
Travelers: Immunizations may be required for travel through
various regions where infectious diseases not seen in the country of
origin are endemic.
- Anti-Venoms:
Specific poisonous animal's vaccines [snake, spiders, etc.].
Vaccines against HIV, Lyme disease and various
other pathogens are currently under study.
Regarding Live-microbial
vaccines:
- They should not be given simultaneously with
immune globulin; ideally - such vaccines should be given 2 wk before
or 6 to 12 wk after the immune globulins.
- They usually should not be given to
immunocompromised or pregnant patients. .
Routine Immunizations - Adults
- Measles, mumps and rubella
attenuated live viruses - The 3 are combined into one vaccine
that is routinely given to all children in their 2nd yr of life.
However, some adults have never received this vaccine and did not
become infected with these diseases in youth. Some who received the
vaccine have not maintained a high titer of antibodies and may be at
risk. Generally, people born before 1956 are considered immune by
virtue of prior infection. Those born after 1956 should receive the
combined vaccine if their immune status is uncertain or if they are
likely to become exposed. Although these vaccines can be given
separately, the combined form is preferred because a person who needs
one vaccine probably needs all three, and revaccination poses no
particular risk.
- Tetanus toxoid is
combined with diphtheria toxoid in tetanus and
diphtheria toxoids adsorbed (Td). Although tetanus is rare, it
has a high mortality rate. Since 1/3 of cases result from only minor
injuries, universal vaccination remains necessary. Adults who missed
the primary series of three tetanus injections in childhood should
receive an initial dose, followed by a 2nd dose 1 mo later, and a 3rd
dose 6 mo later. Thereafter, a booster of q 10 yr maintains lifelong
immunity (all doses 0.5 mL IM). Alternatively, some authorities
recommend a single booster at age 50 because of excellent long-term
protection from the primary immunization.
- Hepatitis B (HB) vaccine
is recommended as a one-time series of three or four injections, but a
person with known exposure may be revaccinated if the antibody titer
is low. Candidates for vaccination include anyone at risk for exposure
to the virus through blood or sexual contact, including health care
workers, mortuary workers, patients receiving frequent transfusions or
hemodialysis, IV drug users, homosexual males, and sex partners of
known HB carriers. Additionally, anyone not previously infected who is
exposed to the virus (eg, a nurse with an inadvertent needlestick
injury) should be vaccinated.
- Influenza A virus
undergoes antigenic drift each year, requiring annual revaccination
with the new strains. Because outbreaks usually begin in early or
midwinter, the vaccine should be given in the fall. It is recommended
for those at high risk for serious sequelae, including anyone > 65
yr; residents of extended-care facilities; and patients with chronic
cardiovascular or pulmonary disease, metabolic disorders, renal
failure, hemoglobinopathies, immunosuppression, or HIV infection.
Health care workers and anyone desiring to avoid symptoms should also
be vaccinated. During influenza outbreaks in extended-care facilities,
amantadine or rimantadine can be prescribed regardless of vaccination
status.
- Pneumococcal pneumonia
vaccine is a polyvalent preparation containing antigens from
the 23 most virulent of the 83 subtypes of pneumococcus. Its overall
efficacy in preventing bacteremia in adults has been reported to be 56
to 81%, but this rate is somewhat lower in debilitated elderly people.
It should be given to anyone at high risk for pneumococcal pneumonia
or its complications, including patients at risk for influenza
complications and those with functional asplenia, alcoholism,
hematologic malignancy, or CSF leak. The vaccine may be given
simultaneously with the influenza A vaccine but at a different site (eg,
the opposite deltoid muscle). One immunization is recommended for
lifetime protection, although revaccination q 6 yr should be
considered for high-risk patients.
- Varicella vaccine
contains live, attenuated virus. It is indicated for young adults not
previously infected, especially health care workers and close contacts
of immunocompromised persons. It produces detectable varicella
antibodies in 97% of recipients and reduces the likelihood of clinical
illness by 70% after exposure. No immune globulins, including
varicella-zoster immune globulin, should be given within 5 mo before
or 2 mo after vaccination. This vaccine may be given concomitantly
with measles-mumps-rubella. Recipients should avoid salicylates for 6
wk because of the possibility of Reye's syndrome.
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