Vaccine Recommendations for Infants and Children
Each traveler needs to be fully up to date with routine
childhood vaccinations because diseases covered by these vaccines
that are now rare or nonexistent in the United States are still common
in other areas of the world. The recommended childhood and adolescent
immunization schedule is depicted in Table 7–1.
Table 7–2 depicts the catch-up schedule
for children and adolescents who start their vaccination schedule
late or who are >1 month behind. This table also describes the
recommended minimal intervals between doses for children who need
to be vaccinated on an accelerated schedule, which is sometimes required
for international travel. Vaccination against yellow fever is required
for travel to some countries (see Yellow
Fever Vaccine Requirements and Information on Malaria Risk and Prophylaxis,
by Country). Recommendations for other vaccines and immunobiologics
depend on the area of travel and health status of traveler and include
Hepatitis A vaccine or immune globulin and vaccinations for typhoid,
meningitis, Japanese encephalitis, rabies, and influenza. Administration
of these vaccines should not interfere with or postpone administration
of any of the recommended childhood immunizations. If necessary,
some portions of the vaccine schedule can be accelerated so that
as many vaccines as possible can be given before departure. In children
with chronic illnesses, decisions regarding vaccinations should be
made in cooperation with their personal physicians.
Modifying the Immunization Schedule for Inadequately
Immunized Infants and Younger Children before International Travel
Factors influencing recommendations for the age at
which a vaccine is administered include the age-specific risks of
the disease and its complications, the ability of people of a given
age to respond to the vaccine, and the potential interference with
the immune response by passively transferred maternal antibody. Vaccines
are recommended for the youngest age group at risk for developing
the disease whose members are known to develop an adequate antibody
response to vaccination.
The routine immunization recommendations and schedules
for infants and children in the United States do not provide specific
guidelines for infants and young children who will travel internationally
before the age when specific vaccines and toxoids are routinely recommended.
The following section provides additional guidance for active and
passive immunization of such infants and children. Additional information
about all the diseases and vaccines mentioned below can be found
in Chapter
3 (Specific Recommendations for Vaccinations and Disease Prevention).
Routine Infant and Childhood Vaccine-Preventable
Diseases
Diphtheria and Tetanus Toxoid and Pertussis
Vaccine
Diphtheria is an endemic disease in many low-income
countries and has been found in the independent countries of the
former Soviet Union. Tetanus occurs worldwide.
Pertussis is common in resource-poor countries and
in other areas where pertussis immunization levels are low. Infants
and children leaving the United States should be as well immunized
as possible. Optimum protection against diphtheria, tetanus, and
pertussis in the first year of life is achieved with three doses
of diphtheria and tetanus toxoids and acellular pertussis vaccine
(DTaP), the first administered when the infant is 6–8 weeks
of age and the next two at 4- to 8-week intervals. A fourth dose
of DTaP should be administered 6–12 months after the third
dose when the infant is 15–18 months of age. A fifth (booster)
dose is recommended when the child is 4–6 years of age. The
fifth dose is not necessary if the fourth dose in the primary series
was given after the child's fourth birthday.
Table 7–1.
Recommended Childhood & Adolescent Immunization Schedule,
2003
Table 7–2.
Catch-up Schedule, 2003
|
|
Two doses of DTaP received at intervals at least
4 weeks apart can provide some protection; however, a single dose
offers little protective benefit. Parents should be informed that
infants and children who have not received at least three doses of
DTaP might not be fully protected from pertussis. For infants and
children <7 years of age, if an accelerated schedule is required
to complete the series before travel, the schedule may be started
as soon as the infant is 6 weeks of age, with the second and third
doses given 4 weeks after each preceding dose. The fourth dose should
not be given before the infant is 12 months of age and should be
separated from the third dose by at least 6 months. The fifth (booster)
dose should not be given before the child is 4 years of age.
Measles Vaccine
Measles is an endemic disease in many low-income
countries and in other countries where measles immunization levels
are low. Because the risk of contracting measles in many countries
is greater than in the United States, infants and children should
be as well protected as possible before traveling. Infants and children
who travel or live abroad should be vaccinated at an earlier age
than is recommended for infants and children who remain in the United
States. Before their departure from the United States, infants and
children of 12 months of age or older should have received two doses
of MMR vaccine separated by at least 28 days, with the first dose
administered on or after the first birthday. Infants 6–11 months
of age should receive a dose of monovalent measles vaccine before
departure. If monovalent measles vaccine is not available, no specific
contraindication exists to administering MMR to infants 6–11
months of age. However, because the risk for serious disease from
either mumps or rubella infection among infants is relatively low
and because infants <12 months of age are less likely to develop
serologic evidence of immunity when vaccinated with MMR antigens
than are older infants and children, mumps and rubella vaccines generally
are administered only to infants and children 12 months of age or
older. Infants administered monovalent measles vaccine or MMR before
their first birthday should be considered potentially susceptible
to all three diseases and should be revaccinated with two doses of
MMR, the first of which should be administered when the infant is
12–15 months of age (12 months if the infant remains in an
area where disease risk is high) and the second at least 28 days
later.
Parents who travel or live abroad with infants <12
months of age should have acceptable evidence of immunity to rubella
and mumps, as well as measles, so they will not become infected if
their infants contract these diseases. An infant <6 months of
age is usually protected against measles, mumps, and rubella by maternally
derived antibodies and ordinarily does not need additional protection
unless the mother is diagnosed with measles.
Mumps and Rubella Vaccine(s)
Because the risk of serious disease from infection
with either mumps or rubella in infants is low, mumps and rubella
vaccine(s) generally should not be administered to infants <12
months of age unless measles vaccine is indicated and single-antigen
measles vaccine is not available. However, parents of an infant <12
months of age should be immune to mumps and rubella so they will
not expose the infant or become infected if the infant becomes ill.
Varicella Vaccine
Varicella (chickenpox) is an endemic disease throughout
the world. A single dose of varicella vaccine should be administered
to all susceptible infants and children without contraindications
at 12 months of age or older. Infants and children who have a reliable
history of having had chickenpox do not need to be vaccinated. Infants <12
months of age are generally protected from varicella because of passive
maternal antibody.
Polio Vaccine
Because OPV is no longer used for routine immunization
in the United States, all infants and children should receive four
doses of IPV at 2, 4, and 6–18 months and 4–6 years of
age. If accelerated protection is needed, the minimum interval between
doses should be 4 weeks, although the preferred interval between
the second and third doses is 2 months. Infants and children who
have initiated the poliovirus vaccination series with one or more
doses of OPV should receive IPV to complete the series.
Haemophilus influenzae Type b Conjugate Vaccine
Haemophilus influenzae type b (Hib) is an
endemic disease worldwide. Risk of acquiring the disease might be
higher in resource-poor countries than in the United States. In the
United States, three types of Hib conjugate vaccines are available.
One Hib conjugate vaccine for infants is also available as a combined
DTaP-Hib vaccine. Routine Hib vaccination beginning at 2 months of
age is recommended for all U.S. children. The first dose may be given
when an infant is as young as 6 weeks of age. Hib vaccine should never be
given to an infant <6 weeks of age. A primary series consists
of two or three doses (depending on the type of vaccine used) separated
by 4–8 weeks. A booster dose is recommended when the infant
is 12–15 months of age.
If Hib vaccination is started when the infant or
child is 7 months of age or older, fewer doses may be required. If
different brands of vaccine are administered, a total of three doses
of Hib conjugate vaccine completes the primary series. After completion
of the primary infant vaccination series, any of the licensed Hib
conjugate vaccines may be used for the booster dose when the infant
is 12–15 months of age.
Infants and children should have optimal protection
before traveling. If previously unvaccinated, infants <15 months
of age should ideally receive at least two vaccine doses before travel.
An interval as short as 4 weeks between these two doses is acceptable.
Unvaccinated infants and children 15–59 months of age should
receive a single dose of Hib vaccine.
Hepatitis B Vaccine
Hepatitis B vaccine is recommended for all infants,
with the first dose administered in the first 2 months of life, preferably
at birth. Infants and young children who have not previously been
vaccinated and who are traveling to areas with intermediate and high
hepatitis B virus (HBV) endemicity are at risk if they are directly
exposed to blood from the local population. Circumstances in which
HBV transmission could occur include receipt of blood transfusions
not screened for HBV surface antigen (HBsAg), exposure to unsterilized
needles (or other medical or dental equipment) in local health facilities,
or continuous close contact with local residents who have open skin
lesions (impetigo, scabies, or scratched insect bites). Such exposures
are most likely to occur if an infant or a child is living for long
periods in smaller cities or rural areas and in close contact with
the local population.
Infants and children who will live in an area of
intermediate or high HBV endemicity for 6 months or more and who
are expected to have the preceding exposures should receive the three
doses of HBV vaccine. The interval between doses one and two should
be 1–2 months. Between doses two and three, the interval should
be a minimum of 2 months; the interval between doses one and three
should be at least 4 months. The third dose should not be given before
the infant is 6 months of age.
Other Vaccines and Immune Globulin
Typhoid Vaccine
Typhoid vaccination is not required for international
travel. No data are available concerning the efficacy of typhoid
vaccine in infants. Breast-feeding is likely to be protective against
typhoid; careful preparation of formula and food from safe water
and foodstuffs should protect infants who are not breast-fed. Typhoid
vaccine is recommended for children 2 or more years of age traveling
to areas where there is a recognized risk of exposure to Salmonella Typhi,
particularly if they are traveling to highly disease-endemic areas.
Yellow Fever Vaccine
Because infants are at high risk for developing encephalitis
from yellow fever vaccine, vaccination of infants should be considered
on an individual basis. Although the incidence of these adverse events
has not been clearly defined, 14 of 18 reported cases of postvaccination
encephalitis were in infants <4 months old. One fatal case confirmed
by viral isolation was in a 3-year-old child. The ACIP recommends
that yellow fever vaccine never be given to infants <6 months
of age. Yellow fever vaccine can be given to infants and children >9
months of age if they are traveling to or living in areas of South
America and Africa where yellow fever infection is officially reported
(see Summary
of Health Information for International Travel, also known
as the “Blue Sheet”) or to countries that require yellow
fever immunization (see Chapter
2: Yellow Fever Vaccine Requirements and Information on Malaria Risk
and Prophylaxis, by Country). Infants and children >9 months
of age should be immunized if they travel to countries within the
yellow fever endemic zone (see Chapter
2, Yellow Fever Vaccine Requirements and Information on Malaria Risk
and Prophylaxis, by Country, and Maps 3–9 and 3–10).
Travelers with infants <9 months of age should be strongly advised
against traveling to areas with epidemic yellow fever. Infants 6–8
months of age should be vaccinated only if they must travel to areas
of ongoing epidemic yellow fever and a high level of protection against
mosquito bites is not possible. Physicians considering vaccinating
infants aged <9 months should contact the Division of Vector-Borne
Infectious Diseases (970-221-6400) or the Division of Global Migration
and Quarantine (404-498-1600) at CDC for advice.
Hepatitis A Vaccine or Immune Globulin for Hepatitis
A
Infants and children traveling to low income countries
are at increased risk for acquiring hepatitis A virus (HAV) infection,
especially if their travel is outside usual tourist routes, if they
will be eating food or drinking water in settings of questionable
sanitation, or if they will be in contact with local residents in
settings of poor sanitation. Although HAV is often not severe in
infants and children <5 years of age, those infected efficiently
transmit infection to other infants and children and to adults. IG
should be given to infants <2 years of age in the same schedule
as that recommended for adults (Table
3–7). Children 2 or more years of age should receive the
pediatric formulation of HAV vaccine or IG. The first dose of vaccine
should be administered as soon as travel to countries with high or
intermediate endemicity is considered. Many children will have responded
to the vaccine by 2 weeks after the first vaccine dose. One month
after receiving the first dose of hepatitis A vaccine, 94%–100%
of adults and children will have protective concentrations of antibody.
However, travelers who need optimal protection earlier than 4 weeks
after the first dose of vaccine should also receive IG at a different
injection site.
Meningococcal vaccine
Meningitis primarily affects children and adolescents,
with high morbidity and mortality rates. Vaccination is recommended
for travel to a disease-endemic area during the dry seasons. The
currently available vaccine in the United States is a tetravalent
polysaccharide vaccine (unconjugated.) A conjugated vaccine is in
large-scale trials and appears to provide good efficacy in children <2
years of age. With the current vaccine, children <2 years old
may be able to generate a partial response to serotype A; thus, vaccinating
infants going to high-risk areas can provide some degree of protection.
Japanese encephalitis vaccine
JE is transmitted by primarily night-biting Culex mosquitoes
in rural areas of Asia and the Pacific Rim. Most reported cases are
in children. Although asymptomatic or very minor infections exist
in disease-endemic areas, symptomatic infections have up to 25% mortality
and 30%-80% incidence of neurologic deficits in survivors. The risk
to short-term travelers and those who confine their travel to urban
centers is very low. Expatriates and travelers living for prolonged
periods in rural areas where JE is endemic or epidemic are at greatest
risk. Travelers with extensive unprotected outdoor, evening, and
nighttime exposure in rural areas, such as might be experienced while
bicycling, camping, or engaging in certain occupational activities,
might be at high risk even if their trip is brief.
Influenza vaccine
Influenza vaccine can be used to reduce risk of influenza
infection in transmission season (November–February in the
Northern Hemisphere, April–September in the Southern Hemisphere,
throughout the year in the tropics). Children at high risk for complicated
influenza infections should be vaccinated, including those with asthma,
cystic fibrosis, and other pulmonary diseases; hemodynamically significant
cardiac disease; immunosuppressive disorders or therapy; sickle-cell
anemia and other hemoglobinopathies; diseases requiring long-term
aspirin therapy; and chronic renal or endocrine diseases.
— Tamara
Fisk
|