There are two hepatitis A (Hep A) vaccines on the market, Havrix and Vaqta, each
with adult and pediatric formulations. The pediatric formulations of the vaccine are
indicated for infants older than 12 months of age and contain half the antigen of the
37 Vaccination involves a two-dose regimen with the second dose
to be administered 6 to 18 months after the initial dose, depending on the formulation
(see Table 64-1). Two doses of hepatitis A vaccine should be administered at least 6
months apart to previously unvaccinated persons who live in areas where
vaccination programs target older children, or who are at increased risk for
27 Adults for whom Hep A vaccination is recommended include those with
high-risk behaviors, individuals who work with hepatitis A virus-infected primates
or in a hepatitis A research laboratory setting, patients with chronic liver disease or
who require clotting factor concentrates, and those traveling to areas where hepatitis
28–30,37 A combination vaccine containing both Hep A and Hep B is
available and indicated in individuals older than 18 years of age on a three-dose
Diphtheria/Tetanus/Pertussis Vaccines
Pertussis (“whooping cough”), an infectious disease caused by Bordetella
pertussis, is characterized by a paroxysmal cough with a whoop-like, high-pitched
inspiratory noise; vomiting; and lymphocytosis. It is a highly communicable infection,
which can affect 90% of infants and young children in nonimmunized households, and
can be associated with serious sequelae, particularly in young infants. An estimated
0.3% to 14% of patients with pertussis experience encephalopathy, 0.6% to 2% have
permanent neurologic damage, and about 0.1% to 4% die.
infection has been mitigated with the availability of an acellular pertussis vaccine
(aP), which commonly is administered in combination with diphtheria (D) and
tetanus (T) vaccines (DTaP). A primary series of four doses of DTaP is
recommended at 2, 4, 6, and 15 to 18 months followed by a booster dose at school
41 The efficacy of the DTaP vaccines against pertussis
after primary immunization (three doses) is greater than 80%.
to 90% after the last booster (age 4–6 years) and then decreases during the next 12
years, after which protection is minimal.
Historically, DTaP vaccines contained whole cell pertussis antigens. However,
because of concerns regarding adverse effects, products currently available contain
acellular pertussis antigens (see Table 64-1). Despite a more favorable adverse
effect profile, the DTaP vaccine is contraindicated in anyone experiencing an
anaphylactic reaction or encephalopathy within 7 days of immunization with DTaP
when these symptoms cannot be attributed to another cause.
consideration of subsequent doses should be given to infants experiencing a
temperature of 105°F (not resulting from another cause) or persistent, inconsolable
crying lasting more than 3 hours within 48 hours after the administration of a
41 The pertussis component of the DTaP vaccine should
be eliminated (i.e., continue vaccination with DT) in any child experiencing collapse
or a hypotonic–hyporesponsive episode. If an evolving neurologic disorder is
present, pertussis immunization should be deferred until the neurologic problem has
been fully evaluated. Preexisting, stable neurologic conditions (e.g., well-controlled
seizures) are not contraindications because the benefits of pertussis immunization
outweigh the risks. A family history of seizures or other central nervous system
(CNS) disorder is not a contraindication for vaccination.
Two DTaP vaccines (Infanrix and Daptacel) are approved for the primary
vaccination series. Combination vaccines may also be used; however, their use for
primary vaccination is product dependent (Table 64-2).
product should be used for all five doses because the immunity, safety, and efficacy
associated with the interchanging of different DTaP vaccines are unknown.
product information is unknown or unavailable from prior vaccinations, however,
any licensed DTaP vaccine can be used to complete the vaccination series.
Despite the availability of an effective vaccine and a high rate of vaccine
coverage, pertussis remains poorly controlled in the United States.
immunity in adolescents and adults is believed to contribute to this problem. About
12% of adult patients with a cough lasting more than 2 weeks have pertussis.
Although the illness is typically mild in adults and adolescents, they serve as a
source of transmission to unprotected infants. This has led to the development and
recommendation of acellular pertussis booster vaccines for adolescents and adults
with a tetanus and diphtheria toxoids and acellular pertussis vaccine (Tdap).
(Note the designation as dap compared with DaP for primary vaccines.) The routine
use of a single dose of pertussis booster (Tdap) is recommended for adolescents at
11 to 18 years of age, for adults 19 to 64 years of age, pregnant females during each
pregnancy, and for those older than 65 years of age who may be in contact with
infants younger than 12 months of age.
27–30,44,46 The pertussis booster (Tdap) may be
administered regardless of the time since receipt of a tetanus booster (Td). Two
Tdap vaccine formulations (BOOSTRIX and ADACEL) are US Food and Drug
Administration (FDA)–approved for use as a booster dose for children 11 to 18
44 Recommendations for catch-up immunization of unvaccinated or
undervaccinated individuals with DTaP/Tdap are available.
receive the Tdap vaccination, particularly because she works in an environment with
young children, and she has not received a booster since her childhood DTaP series.
She may be given a dose without regard to her prior tetanus booster vaccination.
Diphtheria and tetanus toxoids have been administered in combination with
pertussis vaccination in the United States since the 1940s. Both diphtheria and tetanus
are rare diseases in the United States as a result of universal childhood immunization.
When disease does occur, it does so primarily in the elderly or those who were
47 For both diseases, it is the toxin-producing strains
(toxigenic Corynebacterium diphtheriae and Clostridium tetani) that result in severe
disease and, therefore, the vaccine antigens target the toxoids which they produce.
The concentration of diphtheria toxoid in vaccine preparations for adults (designated
as d as compared with D in primary vaccination) is reduced relative to those for
children owing to increased reactions with repeated injections and improved
response to lower antigen doses.
47 DTaP and diphtheria and tetanus toxoids (DT) are
to be used for primary vaccination in children younger than 7 years of age, whereas
the tetanus and diphtheria toxoids (Td) are for use in children older than 7 years of
age and adults. Booster doses of tetanus (Td) should be administered every 10
Haemophilus influenzae type b (Hib) was the most common cause of bacterial
meningitis and a leading cause of serious, systemic
bacterial diseases in children younger than 5 years of age until an effective vaccine
was added to the routine immunization schedule.
48–50 The mortality rate associated
with Hib meningitis was approximately 5%, with neurologic sequelae observed in
52 Epiglottitis, cellulitis, septic arthritis, osteomyelitis,
pericarditis, and pneumonia also were commonly caused by H. influenzae. Although
H. influenzae is associated with otitis media and respiratory tract infections, type b
strains account for only 5% to 10% of these infections.
QUESTION 1: P.M. is a 12-month-old child who has not been immunized against Hib. His parents wish to
against Hib should he receive?
The Hib vaccine is a conjugate polysaccharide vaccine which is associated with a
95% reduction in the incidence of Hib disease in children younger than 5 years of
54 The three currently available monovalent conjugate Hib vaccines are as
follows: Hib meningococcal protein conjugate vaccine or PRP-OMP (PedvaxHIB),
Hib tetanus toxoid conjugate vaccine or PRP-T (ActHIB and Hiberix).
immunogenicity of the conjugate vaccines are age-dependent (i.e., older children
have an improved immune response).
55 The three conjugated vaccines are all
approved for use in infants, the group at greatest risk for H. influenzae infection;
however, they vary in their dosing regimens. The HbCV immunization series requires
a priming series followed by a booster dose at 12 to 15 months. PRP-OMP’s primary
series is administered at 2 and 4 months of age in contrast to a schedule of 2, 4, and 6
months’ primary series for the other vaccines.
Ideally, the primary series should
be completed with the same HbCV; however, data support the interchangeability of
the products for the priming and booster doses.
If PRP-OMP is used in a priming
series with another HbCV, the number of doses necessary to complete the series for
the other product should be administered.
56 Combination vaccines may also be used
according to indications for each (see Table 64-2).
The number of doses of HbCV vaccine needed in previously unimmunized older
infants and children depends on their age at presentation. Children who begin HbCV
at 7 to 11 months of age should receive a primary series of two doses of a vaccine
containing PRP-T, or PRP-OMP followed by a booster dose at 12 to 18 months of
age administered at least 2 months after the previous dose.
15 months should receive a primary series of one dose followed by a booster dose 2
months later. If a child reaches 15 months of age without receiving HbCV, only one
56 HbCV is not routinely recommended in children younger than 5
years of age or adults. Adults who have anatomical or functional asplenia or sickle
cell disease, or are undergoing elective splenectomy should receive 1 dose of Hib
vaccine if they have not previously received Hib. Adults with a hematopoietic stem
cell transplant (HSCT) should receive 3 doses of Hib in at least 4-week intervals 6
to 12 months after transplant regardless of their Hib history. Hib is not routinely
recommended for adults with human immunodeficiency virus infection because their
risk for Haemophilus influenzae type b infection is low.
Polio, an infectious disease caused by a highly contagious enterovirus, can strike at
any age, but primarily affects children younger than 3 years of age (>50% of cases).
The three identified serotypes of poliovirus are transmitted person to person by
direct fecal–oral contact or indirect exposure to infectious saliva, feces, or
58 After household exposure, 90% of susceptible contacts
57 The poliovirus enters through the mouth and then multiplies in the
throat and intestines. Once established in the intestines, poliovirus can enter the
bloodstream and invade the CNS, which may result in paralysis.
Immunity to polio can be achieved after natural infection with poliovirus;
however, infection by one serotype of the poliovirus does not protect an individual
against infection from the other two serotypes.
through immunization, and the development of effective vaccines to prevent paralytic
polio was one of the major medical breakthroughs of the 20th century. Since the
advent of the trivalent oral polio vaccine (OPV) and inactivated polio vaccine (IPV),
the incidence of paralytic poliomyelitis has been reduced dramatically.
receiving a different form of polio vaccine than she received?
Historically, the live attenuated oral polio vaccine (OPV or Sabin vaccine) was
the formulation of choice in the United States. Its advantages include low cost, ease
of administration, and induction of lifelong immunity.
high level of gastrointestinal immunity, thus preventing the carrier state. The fecal
shedding of the attenuated OPV virus after vaccination is also an effective way to
immunize or boost the preexisting immunity in close contacts.
benefits, OPV carries the risk of vaccine-associated paralytic polio (VAPP),
contrast to OPV, the enhanced IPV (IPOL), which is administered intramuscularly,
has not been associated with VAPP or other reactions.
similar systemic immunity as OPV, it induces less immunity in the gastrointestinal
59 The risks of VAPP from OPV, despite its high efficacy, have resulted in the
recommendation of IPV as the preferred dosage form for childhood
The ACIP and AAP guidelines recommend that all children should receive four
doses of IPV at ages 2 months, 4 months, 6 to 18 months, and 4 to 6 years. The first
dose of vaccine should be administered no sooner than 6 weeks of life.
dose of the four-dose series should be administered after 4 years of age and at least 6
months after the previous dose.
60 Combination vaccines containing IPV are
available and may be used to provide the initial four IPV doses. However, to ensure
adequate immunity, it is recommended that an additional IPV booster be administered
at 4 to 6 years, for a total of five doses
prudent immunization schedule for her if her trip includes travel to a polio-endemic area?
Routine poliovirus vaccination of persons older than 18 years of age is not
necessary in the United States because US residents are at minimal risk of exposure.
should be considered for adults at high risk of polio exposure (e.g., travel to an
area endemic for polio, close contact with children who will be receiving OPV,
close contact with patients who may be excreting wild polioviruses, or work that
requires handling poliovirus specimens).
IPV is the vaccine of choice because
adults have a higher incidence of VAPP from OPV than children. Ideally, L.G. should
receive two doses of IPV, administered 4 to 8 weeks apart, followed by a third dose
6 to 12 months later. If exposure is likely in less than 8 weeks, two doses of IPV
should be administered at least 4 weeks apart.
If L.G.’s travel must be undertaken
on short notice (<4 weeks) she should receive one dose of IPV with receipt of the
remaining doses at a later date according to schedule.
immunized as a child, a single dose of IPV may be considered for booster effect.
Currently, OPV is recommended only in special circumstances, such as
vaccination to control outbreaks of paralytic polio, unvaccinated infants traveling in
less than 4 weeks to areas endemic for polio, and children of parents who reject the
In parents who are concerned about the number of
injections, OPV may be considered for the third and fourth vaccination after
receiving systemic protection with IPV for the first two doses.
poliovirus vaccine that should be used in patients with an immunodeficiency
disorder, those receiving immunosuppressive chemotherapy, or those living with a
person who is known or suspected to have these conditions.
Should she receive meningococcal vaccine?
After dramatic reductions of Streptococcus pneumoniae and H. influenzae type b
strains of meningitis secondary to conjugate vaccines, Neisseria meningitidis has
become a more prominent cause of bacterial meningitis. The ACIP recommends
routine vaccination of adolescents, with first dose at age 11 to 12 years and a booster
at 16 years, persons >2 months of age at increase risk for meningococcal disease, and
patients in at-risk groups to control outbreaks.
61 Patients with increased risk for
meningococcal disease include those with persistent complement deficiencies,
functional or anatomic asplenia, travel to countries where meningococcal disease is
hyperendemic or endemic, or who are at risk during an outbreak. Patients aged 2
months to 55 years not previously vaccinated should receive the vaccination if they
have persistent complement deficiency, functional or anatomic asplenia, have HIV,
are first-year college students in residential housing, travel to countries where
meningococcal disease is hyperendemic or endemic, or who are at risk during an
outbreak, or are microbiologists who are routinely exposed to N. meningitides.
The two available meningococcal vaccine options include two different
conjugated vaccines (MCV) covering serotypes A, C, Y, and W-135 of N.
meningitides. The two conjugate vaccines available (Menactra and Menveo), both
MCV4 conjugate vaccines, are indicated for individuals 11 to 55 years of age.
ACIP recommends administration of this vaccine to all persons at 11 to 12 years of
age (or at high school entry if there is no history of vaccination) and to unvaccinated
college freshmen residing in dormitories. Additionally, as stated earlier, the ACIP
recommends a booster dose around the age of 16 years, and a two-dose primary
vaccination for patients with reduced response to a single dose.
Adverse effects (e.g., fever, headache, chills, malaise, and arthralgias) from both
vaccines are similar and relatively rare; however, the Centers for Disease Control
and Prevention (CDC) and FDA issued a warning regarding the potential for
increased risk of Guillain–Barré syndrome in patients receiving the Menactra
62 Over the course of a 16-month period beginning in June 2005,
15 cases were reported in the 11- to 19-year age group, and two cases in those older
than 20 years of age. All patients recovered. Despite this apparent small increased
risk of Guillain–Barré syndrome, current recommendations remain the same, but
monitoring of this development will continue. No cases of Guillain–Barré syndrome
have been reported with Menveo; however, surveillance is ongoing. At this time, J.C.
should receive one of the two MCV4 vaccines and be advised to receive a booster
would like background information including the role of the human papillomavirus (HPV) vaccine and
recommendations for use of the vaccine in J.S.
HPV commonly infects the genital tract and is primarily transmitted by sexual
contact. Infection with HPV has been associated with cervical cancer as well as
other anogenital cancers (vulvar and vaginal cancers in females and penile cancers in
males), anogenital warts, and recurrent respiratory papillomatosis, and it is estimated
to be the most common sexually transmitted infection in the United States.
affects both sexes with similar infection rates, and it is usually asymptomatic,
66 Acute HPV infections typically resolve without
clinical complications within 1 year; however, 10% to 15% of infections remain
persistent and pose a risk of invasive cervical carcinoma and other anogenital
67 Although not all HPV infections cause cervical cancer, almost all
(99%) cervical cancer in women is associated with a previous HPV infection.
The majority of disease associated with HPV is caused by the HPV types 6, 11, 16,
and 18, with HPV strains 16 and 18 accounting for 64% of invasive HPV-associated
65 and approximately 50% of cervical cancer precursors.
strains 6 and 11 account for the cause of 90% of genital warts and most cases of
recurrent respiratory papillomatosis.
Infection with one strain of HPV does not
prevent infection from other strains; thus, repeated infections can occur through one’s
67 and those with prior HPV infections benefit from immunization as well.
Three vaccines are available for the prevention of HPV infection: a quadravalent
product (Gardasil), a nine-valent product (Gardasil 9), and a bivalent product
(Cervarix). The quadravalent product is active against HPV strains 6, 11, 16, and 18;
the nine-valent product is active against these strains in addition to 31, 33, 45, 52,
and 58. Both of these products are indicated for males and females aged 9 to 26
65 The bivalent product is active against only HPV strains 16 and 18 and is
indicated only for females 10 to 25 years old.
71 Gardasil is indicated for males for
the purpose of prevention of genital warts and anal cancers.
Routine vaccination with any HPV vaccine is recommended for female patients at
Comments
Post a Comment
اكتب تعليق حول الموضوع