Pediatric Annals

1998 Immunization Schedule Changes and Clarifications

Sharon Humiston, MD, MPH; William Atkinson, MD, MPH

Abstract

"You miss 100% of the shots you never take."

Wayne Gretzky

The chief changes and clarifications that have been incorporated into the 1998 Childhood Immunization Schedule and endorsed by the American Academy of Pediatrics (AAP), the American Academy of Family Physicians (AAFP), and CDOs Advisory Committee on Immunization Practices (ACIP), include the following1 (Figure).

RECOMMENDATIONS

Measles-Muraps-Rubella (MMR) Vaccine

The recommended age for the second dose of MMR is now 4 to 6 years.

Polio Vaccine

If a schedule using only inactivated polio vaccine (IPV) is used, the third dose may be given as early as 6 months of age (as is acceptable if a schedule using only live oral polio vaccine [OPV] is used). ACIP continues to recommend a sequential poliovirus vaccination schedule consisting of two doses of IPV - administered at 2 and 4 months of age - followed by two doses of OPV - administered at 12 months and 4 to 6 years of age. The AAP and AAFP do not give preference for any of the three acceptable schedules (ie, all IPV, all OPV, or the sequential IPV-OPV schedule).

When is OPV alone preferred for polio vaccination? An all OPV schedule is preferred when the immunization series is started after 6 months of age, to enhance compliance with the full childhood vaccination schedule. Because of enhanced intestinal immunity, an all OPV schedule may be preferred for children who travel to polio endemic countries to reduce the risk of wild poliovirus infection and subsequent spread. OPV may be preferred whenever parents or providers decline extra injections.

Can I vaccinate a child with OPV if their parents have never been vaccinated against polio? The risk of a contact developing vaccine-associated paralytic polio is very low. However, if it is known that an unvaccinated or inadequately vaccinated person resides in the household, an all-IPV schedule is recommended for the child. The parents may receive IPV, too.

Are IPV and OPV administered on the same schedule? Yes, and this is new. If an all-IPV or all-OPV schedule is used, the primary series is recommended at 2, 4, and 6 months of age. (A minimum interval of 4 weeks between doses #l-#2 and doses #2-#3 are required.) A booster dose is given at school entry, 4-6 years of age.

Why is the third dose recommended at 12- 18 mondis for the sequential schedule, but at 6 months for allAPV and all-OPV schedules? Children with B cell deficiencies are at highest risk for vaccine-associated paralytic polio. It is possible, though unlikely that more children with these, and other immunocompromising illnesses may have been diagnosed by 12 months than by 6 months of age. These children are not protected by IPV and should never receive OPV. It is hoped that by delaying until 12-18 months of age for the first OPV, fewer children with immunocompromising illnesses will mistakenly receive OPV.

If the third dose of OPV is given at school entry, is the fourth dose needed? No. The fourth dose is not required if the third dose is given on or after the fourth birthday.

After what age is routine polio vaccine no longer reeommended? In the U.S., routine polio vaccination is not recommended for persons >18 years old.

How long is oral polio vaccine virus shed in the stool after the dose? Up to 6 weeks. Viral shedding in the stool is generally longest following the first dose and is generally shorter with each subsequent dose.

How much of a dose of OPV can be spit out before the dose needs to be repeated? There is no definite rule. If, in the judgement…

"You miss 100% of the shots you never take."

Wayne Gretzky

The chief changes and clarifications that have been incorporated into the 1998 Childhood Immunization Schedule and endorsed by the American Academy of Pediatrics (AAP), the American Academy of Family Physicians (AAFP), and CDOs Advisory Committee on Immunization Practices (ACIP), include the following1 (Figure).

RECOMMENDATIONS

Measles-Muraps-Rubella (MMR) Vaccine

The recommended age for the second dose of MMR is now 4 to 6 years.

Polio Vaccine

If a schedule using only inactivated polio vaccine (IPV) is used, the third dose may be given as early as 6 months of age (as is acceptable if a schedule using only live oral polio vaccine [OPV] is used). ACIP continues to recommend a sequential poliovirus vaccination schedule consisting of two doses of IPV - administered at 2 and 4 months of age - followed by two doses of OPV - administered at 12 months and 4 to 6 years of age. The AAP and AAFP do not give preference for any of the three acceptable schedules (ie, all IPV, all OPV, or the sequential IPV-OPV schedule).

Recommended Childhood Immunization Schedule United States, January - December 1998

Recommended Childhood Immunization Schedule United States, January - December 1998

Table

TABLE 1Minimum age for initial vaccination and minimum interval between vaccine doses, by type of vaccine

TABLE 1

Minimum age for initial vaccination and minimum interval between vaccine doses, by type of vaccine

Hepatitis B Vaccine

The recommended timing of the third dose of hepatitis B vaccine has been clarified: it should be given at least 2 months after the second dose, at least 4 months after the first dose, but not before 6 months of age.

Haemophilus influenzae Type b (Hib) Vaccine

Hib vaccines from different manufacturers are now considered interchangeable for primary as well as booster vaccination because of data showing excellent immune responses. It is important to note that when PRP-OMP (Merck, Inc.) is given in a series with either of the other licensed products (ie, HbOC from Wyeth-Lederle Laboratories or PRP-T from Pasteur Mérieux Connaught), the recommended number of doses is determined by the other Hib vaccine, not PRP-OMP.

The Early Adolescent (11 to 12 Year) Visit

Although varicella vaccine, the three-dose series of hepatitis B vaccine, and the second dose of MMR vaccine are all recommended at earlier visits, if they have not been given, they should be completed at the routine 11 to 12 year visit. Td (diphtheria and tetanus toxoids) should be given at this visit if at least 5 years have passed since the preceding dose.

Combination Vaccines

It has been noted that combination vaccines may be used whenever any components of the combination are indicated, and its other components are not contra indicated. So, for example, if an office stocks only the trivalent measles-mumps-rubella vaccine and an individual who needs evidence of measles immunity presents with serologic evidence of mumps and rubella immunity, the trivalent MMR may be used because one component (measles) was indicated and its other components were not contraindicated.

Table

TABLE 2Recommended accelerated immunization schedule for infants and children <7 years of age who start the series late-11 or who are >1 month behind in the immunization schedulef (ie, children from whom compliance with scheduled return visits cannot be assured)

TABLE 2

Recommended accelerated immunization schedule for infants and children <7 years of age who start the series late-11 or who are >1 month behind in the immunization schedulef (ie, children from whom compliance with scheduled return visits cannot be assured)

FREQUENTLY ASKED QUESTIONS

General Vaccine Questions2,3

Which vaccines are live virus vaccines and which are inactivated? Live virus vaccines include OPV, MMR, and varicella vaccines. Inactivated vaccines include DTP and DTaP1 Hib, hepatitis B, IPV, influenza, and pneumococcal vaccines. It is important to know this because contraindications, adverse reactions, route of administration, and schedules can often be predicted on this basis.

How long can the interval be between doses of a vaccine series without having to restart the series! With the exception of oral typhoid vaccine, you never have to restart a vaccine series because the interval between doses has been too long. While every effort should be made to adhere to the recommended schedule, if the interval between doses is prolonged, there is no need to restart the series of any vaccine. For example, if a teen got the first hepatitis B vaccine dose at 1 1 years of age and does not return for a year, the second dose may be given at that time.

How short can the interval be between doses of a vaccine series without discounting the dose! See Table 1 for vaccine- and dose-specific minimum intervals and Table 2 for an accelerated schedule. Again, every effort should be made to adhere to the recommended schedule, but for children who are more than 1 month or one vaccine dose behind schedule, the intervals between doses should be reduced to the minimum allowable.

In contrast to prolonged intervals, foreshortened intervals between vaccine doses in a series may diminish vaccine efficacy. For this reason, vaccines given too soon - even 1 day too soon - usually will not be accepted as valid for school entry, and revaccination will be required.

What should I do if a mother says she lost her child's vaccination record, but she believes that the child has had ail his shots! An attempt should be made to verify what vaccines have been received (eg, recheck at home, contact the child's previous doctor or clinic). If a record cannot be located after a reasonable search, the child should be considered unimmunized, and revaccinated as appropriate for the child's age.

Some children get extra vaccines because their records were lost. Some children get extra vaccines because they only need a single antigen and my office only stocL· a combination vaccine. Is extra vaccination dangerous7. Extra doses of live virus vaccines do not appear to have adverse consequences and may even boost immunity. Extra doses of inactivated vaccines can induce very high antibody titers. If individuals with very high antibody levels are re-vaccinated, large local inflammatory (Arthus) reactions may ensue. Such reactions may be uncomfortable, but they are not dangerous.

What childhood vaccines may be given simultaneously7. All vaccines used for routine childhood vaccination in the United States may be given simultaneously. There is no evidence that simultaneous administration of vaccines either reduces vaccine effectiveness or increases the risk of adverse events.

Children are getting too many injections these days. If parents want to delay vaccinations, what vaccination should they defoyl Don't delay. For parents concerned about the number of injections, the following options to decrease the number of injections at the 2 and 4 month visits may be helpful:

* schedule the hepatitis B vaccine series at 0, 1, and 6 months

* use OPV instead of IPV

* use combination vaccines (eg, Hib-hepatitis B)

Additional vaccination visits should be scheduled only as a last resort. Although parents mean well, there is no guarantee that they will return, and the child may remain unvaccinated or undervaccinated.

Some children's records show vaccines given in the wrong site (eg, buttocks) , via the wrong route (eg, intramuscular given as subcutaneous), or the wrong dose. Should I count these doses7. No. Only full doses given via the right route and in an acceptable site should be counted. To ensure immunity, people who received inappropriate vaccination should be revaccinated according to age. The exception to this involves live injected vaccines (MMR, varicella, and yellow fever), which are all recommended to be given subcutaneously. Intramuscular administration of these is not likely to decrease immunogenic ity so doses given intramuscularly do not need to be repeated.

If an infant needs more than one intramuscular iry'ection in a single leg, which ones should be given in the same leg7 There is no absolute rule, but a reasonable approach is to place the vaccine most likely to cause a local adverse reaction (eg, DTP) in one leg and the two less reactive vaccines in the other leg.

What length of needle is recommended for vaccines given to children and adults?

* Subcutaneous injections (MMR, varicella, IPV): in both children and adults, a 5/8 to 3/4-inch, 23to 25-gauge needle should be used.

* Intramuscular injections: in infants and children, a minimum needle length of 7/8-inch should be used for anterolateral thigh injections, and a minimum of 5/8-inch for deltoid intramuscular injections is recommended. For adults, a 1- to VA -inch needle is recommended.

Some nurses and doctors are concemea about liability if we don't ask for the parent's signature of consent when administering vaccines. Is a signature required for any vaccine? Neither federal law nor the National Vaccine Injury Compensation Program requires a signature as evidence of informed consent prior to administration of vaccine. However, some states may require a signature on the Vaccine Information Statement or Important Information Statement.4

I think my practice's immunization rates are 90% or better. Is my practice unusual7. Research shows that most providers think their immunization rates are excellent, but that their actual immunization rates are not as good.5 The CDOs National Immunization program has developed public domain computer software (Clinic Assessment Software Application or CASA) and other tools to assess immunization rates and diagnose the likely source of the problem. CASA has the capacity to produce patient reminders and recall messages, both known to improve coverage. CASA can be obtained by contacting the National Immunization Program, or from your state or local immunization program, who will also assist your office in performing an assessment.

What are the true contraindications and precautions to vaccination7. There are only two permanent contraindications to vaccination: anaphylactic allergy to a vaccine component or prior dose and, for pertussis vaccine, encephalopathy within 7 days of a prior dose. All vaccines should be withheld if a child has a moderate to severe acute illness, the management of which will be confused by vaccine administration. Live virus vaccines (eg, MMR, varicella, and OPV) are contraindicated if the patient is pregnant or immunosuppressed. (The exception is that people with asymptomatic HIV infection should receive MMR). OPV should not be given to children with immunosuppressed close contacts (IPV should be used instead). Antibodies in blood products, including immunoglobulin, may inactivate varicella and all measles-containing vaccines.

Can I give live vaccines (MMR, OPV, varicella) to my patients on corticosteroids7. Three corticosteroid factors are of importance: dose, route, and duration. If the patient is receiving immunosuppressive doses of steroids (eg, >2 mg/kg/day or >20 mg/day of prednisone) orally or parenterally for more than 14 days, live vaccines should not be given. All vaccines may be administered if lower doses are used, if the steroid preparation is inhaled or topical, or if the regime is an alternate day schedule or for fewer than 14 days.

What vaccines are recommended for children infected with human immunodeficiency virus (HlV)? Are there different recommendations for symptomatic and asymptomatic patients7. The inactivated vaccines recommended are listed below6:

* All routine inactivated vaccines (IPV, Hib, hepatitis B, and DTaP) are recommended for children with either symptomatic or asymptomatic HIV infection.

* Children 2=6 months of age should receive influenza vaccine.

* Children 2*2 years of age should receive pneumococcal vaccine.

The live vaccine recommendations are:

* MMR is recommended for children with HIV infection who are not severely immunosuppressed.7

* OPV is contraindicated in children with either symptomatic or asymptomatic HIV infection; IPV should be used.6

* Varicella vaccine is contraindicated in children with either symptomatic or asymptomatic HIV infection.8

What vaccines are contraindicated if a household contact is immunosuppressed? OPV should not be given if a household contact is immunosuppressed; IPV should be used instead. Other live vaccines (MMR, varicella) and all inactivated vaccines may be given as usual.

What vaccines are contraindicated for a child whose mother or other household contact is pregnant? None. A pregnant household member is not a contraindication to administration of any vaccine.

How long should a woman wait to become pregnant after receiving varicella or MMR vaccine? The ACIP and the American Academy of Pediatrics recommend that a woman not become pregnant for 1 month following varicella vaccination8 or a vaccine containing measles or mumps viruses. Pregnancy should be avoided for 3 months after receiving a rubella-containing vaccine.7

We require a pregnancy test for au females of childbearing age before giving an MMR or varicella vaccination. Is this really necessary? No. ACIP recommends that females of child-bearing age be asked if they are currently pregnant or attempting to become pregnant. Vaccination should be deferred for those who answer "yes." Those who answer "no" should be advised to avoid pregnancy for 3 months following vaccination ( 1 month for single-antigen measles and varicella vaccines) and then should be vaccinated.

Table

TABLEAcceptable evidence of immunity

TABLE

Acceptable evidence of immunity

What vaccines are contraindicated for a child who is breast feeding? None. Breast feeding is not a contraindication to the administration of any vaccine, either to the mother or to the child.

Is prematurity a contraindication? How long should I delay vaccination of a preemie? Prematurity is not a contraindication. Infants born prematurely should be vaccinated at the same chronological age and according to the same schedule as full-term infants. Full doses of vaccine should be used. Of course, OPV should be delayed until the infant has been discharged from the hospital. Note that, regardless of gestational age, infants should not receive routine hepatitis B vaccine until they weigh at least 2000 grams. Infants born to women who are infected with hepatitis B virus (ie, women who are HBsAg positive) must be given hepatitis B vaccine and hepatitis B immunoglobulin as soon as possible after birth, regardless of birth weight.3

If a child recently received a dose of immunoglobulin, for how long should 1 withhold variceUa and measles-containing vaccines? The length of the delay depends on the dose and route of administration of the antibodycontaining product (eg, immune globulin, intravenous immune globulin, whole blood, or components), and ranges from 3 to 11 months. Table 8 in the General Recommendations on Immunization (not printed here) lists the recommended interval for most immune globulin preparations available in the United States. A copy of these general recommendations can be obtained from your state immunization program or from the National Immunization Program.

My patient had a high fever after a DTP. Is this a contraindication to further pertussis vaccine? This situation is a caution against but not an absolute contraindication to further doses of pertussis vaccine. Other cautions include persistent crying for more than 3 hours, hypotonia (hypotonic hyporeflexive episode), or a seizure (with or without fever) following a prior dose. Under usual circumstances, further doses of pertussis vaccine, including acellular pertussis,9 would not be given when a caution is present. However, under certain circumstances (such as a pertussis outbreak in the community) you may decide that the benefit of the vaccine outweighs the risk of another febrile episode, and decide to give the vaccine.

Are minor illnesses like colds, ear infections, and diarrhea a contraindication to vaccination? The ACIP, the American Academy of Pediatrics, and the American Academy of Family Physicians recommend that children with minor illnesses, with or without low-grade fever, should be vaccinated. There is no consistent evidence that these minor illnesses interfere with response to the vaccine, or increase adverse events. Children with more serious illness should be vaccinated as soon as the concurrent illness resolves.

SPECIFIC VACCINES

Varicella Vaccine8

Varicella infection is ubiquitous, leading to 50 to 100 deaths each year in the United States. It is communicable before the rash appears and can be spread by airborne droplet as well as direct contact. The vaccine is composed of attenuated live virus and is quite effective. When wild virus disease "breaks through" following vaccination, symptoms are mild (<50 lesions and no fever). Varicella vaccine is recommended for immunocompetent (1) children 12 to 18 months of age, and all susceptible children by the 13th birthday, (2) susceptible persons at high risk of exposure or severe illness, and (3) susceptible persons likely to expose persons at high risk of severe illness (eg, health care workers). Immunity appears to be long lasting. Zoster is more severe and is four to five times more likely after natural disease than after immunization. The usefulness of post-exposure vaccination is not yet known.

How serious a disease is varicella? Although varicella infection is generally a mild illness in healthy children, each year 50 to 100 children die from varicella and up to 10,000 persons require hospitalization. Eighty percent of persons who die or are hospitalized do not have an underlying disease. Superinfection with drug-resistant bacteria increases morbidity and mortality associated with varicella.

How effective is varicella vaccine? Varicella vaccine provides 70% to 90% protection against varicella infection and 95% protection against severe disease.

How/ long does protection last? Available data from the United States indicate that protection persists for at least 7 to 10 years (ie, since licensure). In Japan, data indicate that protection persists for at least 20 years.

Can varicella vaccine virus be transmitted to contacts? A few instances of transmission of vaccine virus to close (household) contacts have been reported. In almost every instance reported so far, transmission has been documented solely by seroconversion of the contact, not by clinical varicella. The risk of transmission of vaccine virus appears to be very low; it may be higher from vaccinées who develop a varicella- like rash after vaccination.

Should varicella vaccine be administered to a healthy child who has an immunocompromised household contact, such as a sibling with leukemia? Yes. AAP and ACIP both recommend this vaccination. However, because of the small risk of household transmission of vaccine virus, vaccinées who develop a vaccine-related rash should avoid contact with the immunocompromised person while the rash is present. If a susceptible immunocompromised person is inadvertently exposed to a person with a vaccine-related rash, varicella zoster immunoglobulin (VZIG) need not be given because disease associated with this type of transmission should be mild.

Will varicella vaccine prevent shingles in a person who has already had the disease? This is not known at this time.

Measles, Mumps, and Rubella (MMR) Vaccine7

MMR vaccine contains attenuated live viruses. Egg allergy is no longer considered a contraindication, but severe immunosuppression from HIV and gelatin allergy are contraindications. See Table 3 for acceptable evidence of immunity to measles, mumps, and rubella.

Why is MMR vaccine given after the first birthday? Most full-term American infants will receive passive protection against measles, mumps, and rubella in the form of maternal antibody. These antibodies can inactivate the vaccine virus if they are present when the vaccine is administered. By 12 months of age, almost all infants have lost this passive protection, so the vaccine viruses can replicate and induce immunity without interference.

If a single dose of MSAR vaccine is so effective, why do we give a second dose? About 2% to 5% of people do not develop measles immunity after the first dose of vaccine. The second dose is given to provide those who did not develop immunity after the first dose another chance. About 95% of people who did not respond to the first dose will respond to the second.

What is the best age to give the second dose of MMR vaccine? The recommended time for the second dose of MMR is at school entry (4 to 6 years of age). MMR may be given anytime, as long as the child is younger than 12 months of age and more than 1 month has passed since the first dose. Individuals who have not gotten a second dose before entry to middle school (11 to 12 years of age) should get it at that time.

Can I give a PPD (tuberculin skin test) on the same day as a dose of MMR vaccine? Yes. A PPD can be done before or at the same time as measles vaccine is given. Live measles vaccine can reduce the reactivity to a PPD because of mild suppression of cell-mediated immunity, which can lead to a false- nega ti ve test result. If measles vaccine is given first, the PPD should be delayed fot 4 to 6 weeks.

Why are people bom before 1 957 exempt from receiving MMR vaccine.7 Persons born before 1957 lived through several years of epidemic measles before the first measles vaccine was licensed. As a result, these people are very likely to have had measles disease. Serologic surveys suggest that 95% to 98% of petsons born before 1957 are immune to measles.

How common is arthritis following rubelh vaccine? Joint symptoms are reported by up to 70% of women who get wild rubella disease and 25% to 50% of rubella-susceptible adult women vaccinated with rubella vaccine. Post-vaccination joint symptoms are usually mild and transient. Rarely, a woman develops persistent or recurrent joint symptoms after vaccination, but it is not known if this is simply temporal association or if there is a causal relationship. Some studies show that the risk of chronic arthropathy is not increased by rubella vaccine. Nonetheless, chronic arthritis is a condition for which people can receive compensation through the National Vaccine Injury Compensation Program.

If a child received a single antigen measles vaccine in Mexico when over the age of one, and the child received an MMR riere at least a month later, is that child required to receive a second MMR at entry to kindergarten or seventh grade? Although regulations vary from state to state, the child probably will not require another MMR because most states require two doses of measles, but only one dose of mumps and rubella vaccines. Measles vaccine given after the first birthday is considered to be a valid dose, regardless of the country where it was administered. If the second dose of measles vaccine was administered at least 1 month later, this is also considered to be a valid dose. Some states specify that both doses of measles vaccine be administered as MMR, in which case the child would need a second dose of MMR.

A healthy 15 -month-old with no MMR was exposed to chickenpox yesterday. Can I give the MMR vaccine today? Yes. Disease exposure, including chickenpox, is not a contraindication to MMR or any other vaccine.

Polio Vaccines10

Polio is being eradicated. To reduce the number of people who get polio from (live) OPV while keeping gut immunity high, the ACIP has recommended an interim sequential schedule that includes IPV at 2 and 4 months of age and OPV at 1 2 to 1 8 months and 4 to 6 years of age. ACIP acknowledges the acceptability of all-OPV or all-IPV (inactivated) alternatives. AAP and AAFP recommend that families choose between these schedules. It is anticipated that moving away from primary reliance on OPV will lead to a lower incidence of vaccine-associated paralytic polio (VAPP). Additionally, it will prepare us for the change to primary reliance on IPV in the time immediately preceding and following polio eradication, before polio vaccination is completely ceased.

What is the risk of getting vaccine-associated paralytic polio (VAPP) from OPV? Five to ten VAPP cases have been reported annually since OPV was licensed in 1963. From 1980 through 1994, 125 total cases of VAPP were reported and 303 million doses of OPV were distributed. The number of cases of VAPP per doses of OPV distributed varies as follows.

* Overall: 1 case per 2.4 million OPV doses ( 1 per 6.2 million doses among normal recipients).

* Following the first dose: 1 case per 750,000 first doses administered (1 per 1.4 million doses among normal recipients, 1 per 2.2 million doses among contacts).

* Following later doses: 1 case per 27.2 million doses among recipients, 1 per 17.5 million doses among contacts.

The reason for the higher risk following the first dose is probably because the vaccine virus is able to replicate longer in a completely nonimmune infant, thus increasing the risk of emergence of a mutant virus that may cause paralysis.

What are the serious reactions reported following IPV? There are no serious reactions known to occur following IPV.

What if a child had one dose of OPV - should the child now receive one dose of IPV and two doses of OPV? After a dose of OPV, completion of the series with any of the three options (sequential IPV-OPV, OPV alone, or IPV alone) is acceptable. Because the risk of VAPP from second or later doses of OPV is much lower than after the first dose, providers and families may prefer to complete the series with OPV. Four doses of any combination of IPV or OPV by 4-6 years of age constitute a complete series... when they are administered with respect for minimum age and interval requirements.

Isn't IPV less effective than OPV? No. The IPV that has been used in the US since 1987 is as effective as OPV. After two doses of IPV, 2*95% of recipients have protective antibody levels to all types of poliovirus. After three doses, 2*99% have protective antibodies.

Will immunity to polio from IPV wear off? Will children be at risk later in life if they get IPV? No. Protection from IPV appears to be long-lasting. Studies of IPV in Sweden with vaccines of lower potency than U.S. vaccines showed >90% maintained protection against polio 25 years after the fourth dose. A small U.S. study of IPV showed excellent antibody persistence during a 4-year follow-up.

When is IPV alone preferred for polio vaccination? IPV is the only vaccine recommended for immunocompromised persons and their household contacts. IPV alone is also recommended for primary vaccination of persons >18 years of age. An all-IPV schedule may be used any time the number of injections is not likely to decrease compliance with the immunization schedule.

Table

TABLE 4ACIP-recommended Haemophilus influenzae type b (Hib) routine vaccination schedule

TABLE 4

ACIP-recommended Haemophilus influenzae type b (Hib) routine vaccination schedule

When is OPV alone preferred for polio vaccination? An all OPV schedule is preferred when the immunization series is started after 6 months of age, to enhance compliance with the full childhood vaccination schedule. Because of enhanced intestinal immunity, an all OPV schedule may be preferred for children who travel to polio endemic countries to reduce the risk of wild poliovirus infection and subsequent spread. OPV may be preferred whenever parents or providers decline extra injections.

Can I vaccinate a child with OPV if their parents have never been vaccinated against polio? The risk of a contact developing vaccine-associated paralytic polio is very low. However, if it is known that an unvaccinated or inadequately vaccinated person resides in the household, an all-IPV schedule is recommended for the child. The parents may receive IPV, too.

Are IPV and OPV administered on the same schedule? Yes, and this is new. If an all-IPV or all-OPV schedule is used, the primary series is recommended at 2, 4, and 6 months of age. (A minimum interval of 4 weeks between doses #l-#2 and doses #2-#3 are required.) A booster dose is given at school entry, 4-6 years of age.

Why is the third dose recommended at 12- 18 mondis for the sequential schedule, but at 6 months for allAPV and all-OPV schedules? Children with B cell deficiencies are at highest risk for vaccine-associated paralytic polio. It is possible, though unlikely that more children with these, and other immunocompromising illnesses may have been diagnosed by 12 months than by 6 months of age. These children are not protected by IPV and should never receive OPV. It is hoped that by delaying until 12-18 months of age for the first OPV, fewer children with immunocompromising illnesses will mistakenly receive OPV.

If the third dose of OPV is given at school entry, is the fourth dose needed? No. The fourth dose is not required if the third dose is given on or after the fourth birthday.

After what age is routine polio vaccine no longer reeommended? In the U.S., routine polio vaccination is not recommended for persons >18 years old.

How long is oral polio vaccine virus shed in the stool after the dose? Up to 6 weeks. Viral shedding in the stool is generally longest following the first dose and is generally shorter with each subsequent dose.

How much of a dose of OPV can be spit out before the dose needs to be repeated? There is no definite rule. If, in the judgement of the person administering the vaccine, a substantial amount of vaccine is spit out, regurgitated, or vomited shortly after administration (ie, within 5-10 minutes), another dose can be administered at the same visit. If this repeat dose is not retained, neither dose should be counted, and the vaccine should be re-administered at the next visit.

Should OPV be given even when a child is mildly ill with watery diarrhea? In general, yes. The decision whether or not to vaccinate a child with a concurrent illness depends on the severity of the illness.

Can empty OPV dispettes be thrown away in the trash can? No. Dispettes that held live virus vaccines are infectious waste and should be disposed with used needles and syringes.

If there is no polio in the Western Hemisphere, why do we still vaccinate against it? If polio vaccination were stopped in the US, there would be millions of susceptible children within a year. Since wild polio infection still occurs in many parts of the world, the virus could be imported and an epidemic could result.

Diphtheria Toxoid, Tetanus Toxoid, and PertussisContaining Vaccines9

Acellular pertussis vaccine (DTaP) is an inactivated purified subunit vaccine, has a 71%-84% clinical efficacy - equivalent to whole cell pertussis vaccine (DTwP). Three acellular pertussis vaccines have been licensed for tlie primary series in infants: Tripedia(r) (Connaught), the 1997 formulation of ACELlMUNE(r) (Wyeth-Lederle), and lnfanrix(r) (SmithKline Beecham). A fourth DTaP vaccine (Certiva(r), North American Vaccine), is likely to be licensed in the near future. Although the schedule and precautions/contraindications are the same for DTaP and DTwP, DTaP is preferred because it causes fewer local adverse reactions and fever.

Regarding schedules:

* The schedule for all DTaP vaccines is four doses, at 2, 4, 6, and 15-18 months of age.

* The fourth dose can be given if a child is 2*12 months old, six months have elapsed since DTaP 3, and you feel the child is unlikely to return at 15-18 months of age.

* A fifth dose should be given if DTaP 4 was given before the fourth birthday. Tripedia(r) (Pasteur Mérieux Connaught) and Infanrix(r) (SmirhKline Beecham) are not yet licensed for the fifth dose if all preceding doses were DTaP; all brands are acceptable for the fifth dose if any preceding dose was DTwP.

* Children should receive no more than 6 doses of diphtheria or tetanus-containing toxoid before their seventh birthday.

Regarding interchangeability:

* Interchangeability between DTaP and DTwP: DTaP is recommended for all remaining doses for children who started the vaccination series with one, two, three, or four doses of DTwP.

* Interchangeability between DTaP brands. There is no data on the safety or efficacy of a "mix-andmatch" series of acellular pertussis vaccines. The same DTaP vaccine should be used for all doses of the pertussis series whenever possible. If the vaccine a child received for an earlier dose or doses is not available, the acellular vaccine that is available should be given. Pertussis vaccination should NOT be deferred because of the need to use a different type of vaccine.

IfDTaP vaccine is not available, should we continue to give DTP? Yes. DTP and DTP-HIB are safe and effective vaccines and remain acceptable alternatives during the transition period.

If a child received the first four doses of DTP using half -doses and is now 5 years old, how many doses are needed to complete the DTP series? ACIP recommends that anything less than a full dose of any vaccine not be counted in the series. This child will need 4 full doses of DTaP. The first rhree should be separated by 4 weeks, and the fourth should be given 6 months after the third dose.

A 4-year-old received 4 doses of DT because the parents refused pertussL· vaccine. They now want their child to be pertussis immune. What vaccine should I use? ACIP recommends that children receive no more than 6 doses of diphtheria and tetanus toxoids before their seventh birthday. This child could receive 2 doses of DTaP, at which time he would have reached the maximum number of DT doses. No additional doses are recommended. No single antigen pertussis vaccine (whole cell or acellular) is currently available. The parents should be advised that local reactions (eg, pain, redness, swelling) are likely because of the large number of DT doses.

If a child has a contraindication or a precaution to receipt of a subsequent dose of DTwP, should the child instead receive DTaP? No. The contraindications for the DTaP vaccine are the same as those DTwP. Children who experience adverse reactions that are contraindications for subsequent doses of DTwP should receive DT, not further vaccinations with either DTaP or DTwP vaccines.

Should I give DTaP vaccine to a child who has idiopathic epilepsy? The child is being treated and only rarely has seizures. Children with stable neurologic illnesses should be vaccinated with DTaP on the usual schedule.

Can DTaP vaccine be administered to persons who are ≥7 years of age? No. DTaP vaccines are currently licensed only for use in persons who are <7 years of age. In fact, no pertussis-containing vaccines are licensed for use in persons 2*7 years of age.

Is the first booster of tetanus-diphtheria toxoid (Td) now recommended at age 11-12 years? Yes. At the early adolescent visit, the child should receive the first routine booster dose of Td. Since most children will have completed their DTP series 5-7 years earlier, no increase in local adverse events following this dose of Td is expected. (Also, the child should receive varicella vaccine, the second dose of MMR, and the hepatitis B series if they have not already.)

Is there a DTaP-Hxb combination vaccine for use in the primary series? No. The Connaught/Merieux Hib (ActHib(r)) vaccine can be reconstituted with the Connaught DTaP (Tripedia) vaccine, but only for the fourth dose of the series. No combination DTaP-Hib vaccine has yet been licensed for the first three doses of the Hib series.

Haemophilus influenzae Type b (Hib) Vaccine11

Hib vaccine schedule, detailed by conjugate type and age at initiation, is shown in Table 43. Recent data suggest that if Hib vaccine is given before 6 weeks of age, it may make the child incapable of responding to subsequent doses. Thus, no Hib vaccine can be given to infants <6 weeks old.

Can tifie combination hepatitis-Hib vaccine be given at birth? No, this vaccine is not licensed for use in infants < 6 weeks old. Although hepatitis B vaccines can be given at birth, no current Hib vaccine can be given to infants < 6 weeks old.

Why is ProHlBIT (PRP-D) not licensed for use in infants? PRP-D, conjugated to diphtheria toxoid, is not consistently immunogenic in infants so it is not licensed for the primary series in infants. It may be used as the booster dose following a primary series.

How do I finish the Hib series if an infant's first 2 doses were a brand that we don't stock or if I'm not sure what brand he received? The three Hib vaccines licensed for use in infants are interchangeable. Although it is recommended that you use the same brand throughout the primary series, if this is not possible the child should receive a total of 3 doses of any combination of vaccines before the first birthday. Any licensed conjugate vaccine may be used as the booster dose at 12-15 months of age.

What is the minimum age for the last (booster) dose of Hib vaccine? Twelve months, if at least 2 months have passed since the previous dose.

Should any children over 5 years of age get Hib vaccine? Hib vaccine is not routinely recommended over 5 years of age, because very little Hib disease occurs after that age. One dose of Hib vaccine could be considered for children at high risk of invasive Hib disease, such as children without a functional spleen, who were not already appropriately vaccinated.

Hepatitis B Vaccine3

Hepatitis B still causes 5,000-6,000 deaths each year in the US. All infants and teens should get this inactivated vaccine. Perinatally exposed neonates and persons at continued risk of exposure (eg, health care workers) should get post- vaccination testing (one to two months after the third dose; no additional testing is recommended if anti-HBsAg is positive). Neonates should be at least 2000 grams before getting routine hepatitis B vaccination, although these small neonates should get hepatitis B vaccine and HBIG if the mother is acutely or chronically infected.

Non-Routine Vaccines

Hepatitis A12 vaccine is an inactivated whole virus vaccine, has 94%- 100% clinical efficacy, and is recommended for persons ( 1 ) at high risk of exposure [eg, children 5*2 years old in communities with high rates, homosexual men, drug users, people with occupational risk (not health care workers)] or (2) severe illness (eg, chronic liver disease patients).

Influenza13 vaccine is inactivated so it can't cause influenza! Its efficacy is best in healthy people, and against hospitalization and death in the elderly. It is recommended for people >6 months old (1) at increased risk of serious disease or complications (eg, children on chronic aspirin, pregnant women, everyone with certain chronic illnesses or age ^65 years); (2) who have close contact with people in category #1 above (eg, healthcare workers); or (3) who simply don't want to get flu. Immunity from the vaccine is not immediate and it lasts under one year. You should vaccinate people each year from October through mid-November.

Pneumococcal14 disease is a big killer and it may be worse as antibiotic effectiveness is challenged. The vaccine is inactivated (a capsular polysaccharide antigen) that is 60%-70% effective against invasive disease. It is recommended for people ^2 years old at risk because of certain chronic illnesses, immunocompromise, or old age. Licensure of a conjugated vaccine that can be used in infants is anticipated.

REFERENCES

All ACIP statements (MMWR references below) can be obtained by calling the National Immunization Program at 1-800-232-2522. Internet: http://www.cdc.gov/nip.

1. CDC. Recommended childhood immunization schedule - United States, 1998. MMWR. 1998;47:8-12.

2. CDC. General recommendations on immunization.. Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR. 1994:43 (RRl):l-38.

3. Atkinson W, Furphy L, Humiston S, et al. Epidemiology and Prevention of Vaccine- Preventable Diseases. Fourth edition. Department of Health and Human Services. Public Health Service, 1997.

4- CDC. National Childhood Vaccine Injury Act: requirements for permanent vaccination records and for reporting of selected events after vaccination. MMWR. 1988;37:197-200.

5. Dini EF1 Link ins RW, Chaney M. Effectiveness of computer-generated telephone messages in increasing clinic visits. ArrJi Pediatr Adolesc Med. 1995;149:902-905.

6. CEXT. Recommendations of the Advisory Committee on Immunization Practices (ACIP): Use of vaccines and immune globulins in persons with altered immunocompetence. MMWR. 1993;42 (RR- 4H-18.

7. CDC. Measles, mumps, and rubella vaccine use and strategies for measles, rubella. and congenital rubella syndrome elimination and mumps control. Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR. 1998;47 (in press).

8. CDC. Prevention of varicella. Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR. 1996:45 (RR-Il): 1-36.

9. CDC. Pertussis vaccination: Use of acellular pertussis vaccines among infants and young children. Recommendations of the Advisory Committee on Immunization Practices (ACÏP). MMWR. 1997;46 (RR-7):l-25.

10. CDC. Poliomyelitis prevention in the United States: Introduction of a sequential vaccination schedule of Inactivated Poliovirus Vaccine followed by Oral Poliovirus Vaccine. Recommendations of the Advisory Committee on Immunization Practices (AClP). MMWR. 1997:46 (RR-3):l-25.

11. CDC. Haemophilus b conjugate vaccines for prevention of Haemophilus influenzae type b disease among infants and children two months of age and older. Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR. 1991:40 (RR-l):l-7.

12. CDC. Prevention of Hepatitis A through active or passive immunization. Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR. 1996:45 (RR- 15): 1-30.

13. CDC. Prevention and control oí influenza. Recommendations of the Advisory Committee on Immunization Practices (AClP). MMWR. 1996;45 (RR-5):l-24.

14. CDC. Prevention of pneumococcal disease. Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR. 1997:46 (RR-8):l-24.

TABLE 1

Minimum age for initial vaccination and minimum interval between vaccine doses, by type of vaccine

TABLE 2

Recommended accelerated immunization schedule for infants and children <7 years of age who start the series late-11 or who are >1 month behind in the immunization schedulef (ie, children from whom compliance with scheduled return visits cannot be assured)

TABLE

Acceptable evidence of immunity

TABLE 4

ACIP-recommended Haemophilus influenzae type b (Hib) routine vaccination schedule

10.3928/0090-4481-19980601-08

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