28. http://weber.u.washington.edu/;ebm/
29. Birken CS, Parkin PC. In which journals will pediatricians find the best evidence for clinical practice?Pediatrics.1999;103:941–947
30. Haynes BR, McKibbon A, Fitzgerald D. et al. How to keep up with the medical literature: why try to keep up and how to get started.Ann Intern Med.1986;105:149 –153
31. Davidoff F, Haynes B, Sackett D, Smith R. Evidence based medicine.Br Med J.1995;310:1085–1086
32. Cochrane Library. http://www.medlib.com
33. Best evidence database on CD ROM. http://hiru.hirunet.mcmaster.ca/ acpjc
34. US Preventive Services Task Force.Guide to Clinical Preventive Services. 2nd ed. Baltimore, MD: Williams & Wilkins; 1996
35. Spooner AS. On-line resources for pediatricians.Arch Pediatr Adolesc. 1995;149:1160 –1167
36. American Academy of Pediatrics. http://www.pediatrics.org 37. Greco PJ, Eisenberg JM. Changing physicians’ practices.N Engl J Med.
1993;329:1271–1274
38. Haynes RB, Davis DA, McKibbon A, Tugwell P. A critical appraisal of the efficacy of continuing medical education.JAMA.1984;251:61– 64 39. Oxman A, Thomson MA, David DA, Haynes RB. No magic bullets: a
systematic review of 102 trials of interventions to improve professional practice.Can Med J.1995;153:1423–1431
40. Davis DA, Thomson MA, Oxman AD, Haynes RB. Changing physician performance—a systematic review of the effect of continuing medical educational strategies.JAMA.1995;274:700 –705
41. Bauchner H, Simpson L. Specific issues relating to developing, dissem-inating, and implementing pediatric practice guidelines for physicians, patients, families, and other stakeholders.Health Serv Res. 1998;33: 1161–1177
42. Silberg WM, Lundberg GD, Musacchio RA. Assessing, controlling, and assuring the quality of medical information on the Internet:caveant lector et viewer—let the reader and viewer beware. JAMA.1997;277: 1244 –1245
43. Roberts JR, Spooner AS. Pediatric Internet resources: creation and growth of the PEINFO Index.Arch Pediatr Adolesc.1997;151:592–597 44. Wyatt JC, Paterson-Brown S, Johanson R, et al. Randomised trial of
educational visits to enhance use of systematic reviews in 25 obstetric units.Br Med J.1998;317:1041–1046
Experience, Brain, and Behavior:
The Importance of a Head Start
ABSTRACT. Nature and nurture stand in reciprocity, not opposition. All children inherit—along with their parents’ genes—their parents, their peers, and the com-munities they live in. Development unfolds in an eco-logic and a social setting which, just like the genes, is decisive in shaping the organism. The social niche is a crucial link between parents and offspring, an envelope of life chances. It is high time to replace the false dichot-omy between nature versus nurture by a more inclusive trio: nature, niche, and nurture.
Major brain pathways are specified in the genome, but the learned connections between brain and behavior are fashioned by social experience. The luxuriant over-growth of neurons and their processes in embryonic and early life provides the substrate for environmentally in-duced structural change. Activity selects out the synapses
that will persist; inactivity results in regression and ap-optosis. Learning begins in utero and accelerates after birth. Responsive interactions between infants, their par-ents, and other caretakers is crucial to biological no less than psychosocial development. Comprehensive pediat-ric care can help provide a head start to enhance brain development and put the mind on the road to adaptive maturity.
ABBREVIATION. PKU, phenylketonuria.
P
rogress in neuroscience has been simply spec-tacular. We have learned that brain develop-ment is characterized by an initial overproduc-tion of neurons, only half of which will survive, and that experience determines which neurons do sur-vive. The social environment that envelops the child molds the very structure of its brain.1Understanding of the role of genetics in develop-ment has been transformed. Standard teaching in the past treated the relationship between heredity and environment as a dichotomy, commonly phrased as “nature versus nurture.” The source of a given char-acteristic was assigned either to heredity or to envi-ronment. We now recognize that interactions be-tween the products of the genetic code and the salient environment begin before birth and continue throughout life.2
INTERACTIONS BETWEEN NATURE AND NURTURE
The effects of “nature” are dependent on the qual-ity of “nurture” during development; the outcome of “nurture” is dependent on the “nature” of the organ-isms exposed to it. The “heritability” of a trait is defined as the proportion of the variance in that trait attributable to genetic effects; however, the heritabil-ity of a trait calculated in a given study applies only to the population studied under the conditions of the study. If external circumstances change, so will cal-culated “heritabilities.”3 Gene effects vary with the
environment in which development takes place; en-vironmental effects vary with the genetic constitu-tion of the organism growing up in that environ-ment.
The knowledge that disease runs in families is useful in clinical practice because it identifies indi-viduals at risk; prevention becomes possible when research has specified the details of the way nature and nurture interact. For example, halting the mental retardation that appeared to be inevitable in children with phenylketonuria (PKU) was made possible by the discovery that classic PKU results from absence of phenylalanine hydroxylase activity. Some 250 mu-tations result in an abnormal enzyme; what matters is the final common pathway: lack of enzymatic ac-tivity. Because phenylalanine cannot be converted to tyrosine, precursors accumulate and damage the brain. A low-cost method for detecting elevated phenylalanine in the blood of newborns made screening practical. Early detection followed by a phenylalanine-low diet prevents clinical disease. PKU is still an inherited condition; we still cannot
Presented at the XXII International Congress of Pediatrics, Amsterdam, The Netherlands, August 9 –14, 1998.
Dr Eisenberg is Presley Professor of Social Medicine and Professor of Psychiatry, Emeritus, Harvard Medical School.
Received for publication Oct 20, 1998; accepted Oct 26, 1998.
Reprint requests to (L.E.) Harvard Medical School, 641 Huntington Ave, 2nd Floor, Boston, MA 02115-6019.
repair the genetic defect; yet, a change in nurture (that is, a special diet) permits normal— or near nor-mal— development in children with a gene-based metabolic abnormality.
THE ONTOGENETIC NICHE
Nature and nurture stand in reciprocity, not oppo-sition. Offspring inherit their parents, their peers, and the places they inhabit, along with their parents’ genes. West and King4have coined the term
“onto-genetic niche” to emphasize that the organism devel-ops within an ecologic and social setting which, like its genes, it shares with its parents. Neighborhood and neighbors, schools and recreation centers, and housing and parks influence developmental path-ways. The ontogenetic niche is a legacy that guides development, a crucial link between parents and offspring, an envelope of life chances.
Indeed, some effects of niche and nurture on the brain cross generations; they act as if they were “in-herited.” The nurture of the mother-to-be affects the health of the infant she will rear. If she is immune to rubella, her fetus is protected against the congenital rubella syndrome. Her chances of being immunized depend on where she lives; whether in an industri-alized country, where the likelihood of immuniza-tion is high, or in a developing society, where many go unimmunized.5,6But even in industrialized
cotries, the odds are variable. In some councotries, un-warranted fear of adverse vaccine reactions has re-sulted in noncompliance and disease outbreaks.7,8
The nutrition and general health of the prospective mother during her adolescence will influence the risk she will give birth to a premature infant when she does get pregnant. Maternal height is a reflection of earlier malnutrition; height is inversely related to prematurity rates.9 –11How common is growth
stunt-ing? More than half of the children in southern Asia and a third of those in sub-Saharan Africa and Latin America are growing up stunted.12 The infants who
will be born to these female children are at risk for high rates of prematurity.
Attitudes and behaviors about sexuality and par-enthood crystallize during childhood and adoles-cence. The pediatrician can help the boys and girls in his practice acquire healthy attitudes about sexual behavior and parenthood. The goal is to help them rear children who are wanted when they are born and who are born when their parents are mature enough to care for them properly. Children born to teenage mothers, and particularly to single teenage mothers, do far worse than children born to more mature women.13Avoiding sexually transmitted
dis-eases protects against vertical human immunodefi-ciency virus transmission and against the prematu-rity that results from bacterial vaginosis, both more likely after unprotected sex and multiple sexual part-ners. Safe sex behavior depends on knowing how infections are acquired, how they can be avoided, and how to obtain condoms. Pediatricians have an unique opportunity to protect the health of the next generation of children by advocating family life ed-ucation for the youngsters of this generation.14
NEIGHBORS AND NEIGHBORHOODS
The impact of neighbors and neighborhoods as a niche is stunningly illustrated in the findings of the Project on Human Development in Chicago Neigh-borhoods.15,16 Neighborhood structure—
concentra-tion of poverty, extent of ghettoizaconcentra-tion, residential instability—accounts for a significant part of adoles-cent antisocial behavior. However, there is an addi-tional important influence, informal social control, that serves as a significant deterrent to delinquency. Informal social control refers to whether adults in a community keep an eye on children’s play groups, intervene when they find truant youngsters, stop teenagers from hanging out and harassing passersby on street corners, and confront persons who abuse public space. Cohesive communities are able to de-mand and obtain needed resources from city author-ities for police patrols, fire stations, garbage collec-tion, and housing code enforcement. The importance of community activism is evident from the fact that high crime rates are characteristic of neighborhoods scarred by abandoned housing, burned-out build-ings, graffiti, and litter.
The term “collective efficacy” has been proposed to describe the social cohesion among neighbors will-ing to act for the common good. It is a component of social capital. Unstable and poverty-stricken neigh-borhoods with high concentrations of recent immi-grants display low collective efficacy. In turn, low efficacy mediates a substantial part of the association between disadvantage and violence. The ecology of neighbors and neighborhood interact with family characteristics to determine behavioral outcomes.15,16
THE SOCIAL CONSTRUCTION OF THE HUMAN BRAIN
Nature and nurture jointly mold brain structure. The basic plan of the central nervous system is laid down in the human genome, but the detailed pattern of connections result from competition between ax-ons for common target neurax-ons. Because the niche of the species reliably supplies the input for the expect-able connections, major central nervous system structures are as uniform as if the wiring plans were “written” in the genome. But that is not the case; nature is a tinkerer that makes use of the components that are already at hand.17 The regularities of the
the two eyes, driven by spontaneous retinal activity, determines eye-specific lateral geniculate connec-tions.19 Neither the genes governing the retina nor
the genes governing the geniculate specify the ocular alternation layers; interaction between retina and geniculate during embryogenesis is crucial. Interac-tions between the embryo and its uterine environ-ment are evident from the fact that female fetuses nidated in utero next to male rather than female siblings display subtle differences in anatomy and behavior.20 Even mild stress during pregnancy
af-fects birth weight and neuromotor maturation in infant monkeys.21
In humans, we have clear evidence that learning begins before birth! The human fetus in utero hears its mother’s voice more often than any other; on testing shortly after birth, it is able to discriminate that voice from that of other women.22The fetus in
utero has already learned more than voice recogni-tion. It has begun to learn the prosody of its parent tongue. Four-day-old French infants will suck harder to hear a recording of spoken French instead of spo-ken Russian because of in utero auditory experi-ence.23
As to external environmental influences on devel-opment, postnatal stimulation is required to form the ocular dominance columns in the occipital cortex.24
Both eyes of the newborn must receive precisely focused stimulation from the visual environment during the early months of postnatal life to fine-tune the structure of the cortex. If focused vision in one eye of kittens or monkeys is interfered with, the normal eye “captures” most neurons in the occipital cortex in the absence of competition from the de-prived eye. The change becomes irreversible if occlu-sion is maintained through the sensitive period. Hu-man amblyopia, in which there are incongruent visual images from the two eyes, results in perma-nent loss of effective vision from the unused eye if not corrected within the first 5 years of life.
Thus, which of the overabundant neurons live and which neurons die is determined by the amount and consistency of the stimulation they receive. Interac-tion between organism and environment leads to patterned neuronal activity that determines which synapses will persist. Experience molds the brain in a process that continues throughout life. Rats reared in “enriched environments” (that is, large cages with many objects to manipulate) show thicker patterns of interconnection in the cerebral cortex than do those confined in small bare cages.25Rats forced to perform
skilled motor acts have more synapses in the cere-bellum than do animals performing the same amount of motor activity in an exercise wheel.26
CORTICAL REPRESENTATION INCREASES WITH USE
When human brains are mapped by magnetic res-onance imagings, positron emission tomography scans, and magnetoencephalograms, they display marked functional differences that depend on prior experience. The motor cortex of experienced violin-ists display a substantially larger representation for the fingers of the left hand (the one used to play the
strings) than of the fingers of the right (or bowing) arm. Moreover, the brain area dedicated to finger representation is larger in musicians than in nonmu-sicians.27Musicians have a larger planum temporale
on the left than on the right; the asymmetry is great-est in musicians with perfect pitch.28The cortex has a
remarkable capacity for remodeling in response to change inputs. Sterr et al29 contrasted finger
repre-sentation in somatosensory cortex in blind Braille readers who use three fingers on both hands with that for Braille readers using only finger and sighted readers. The investigators found a substantial en-largement of hand representation in the bilateral Braille readers; that enlargement was accompanied by topographic changes on the postcentral gyrus.
If enlargement of cortical areas accompanies in-creases in activity, shrinkage follows loss. Within days after mastectomy, the amputation of a limb or the correction of syndactyly, the cortical sensory map changes. Intact areas enlarge their representation at the expense of areas from which innervation has been removed.30 –32What begins prenatally continues
throughout life. Structure follows function.
AFFECTIVE DEVELOPMENT
Not only does the growth of the child’s intelligence result from social relationships, but so does the or-ganization of its neuroendocrine axis. The multiple sensory inputs that accompany parenting—warmth, odor, touch, sound, motion—all influence the hypthalmic-pituitary adrenal system. Infant ho-meostasis is the outcome of a collaborative process. Infant body temperatures are regulated by caretakers when they respond to signals such as crying or changes in color by holding the infant more closely. Maternal touch and warmth modify infant growth hormone production.
Early experience has long-term effects on the brain and the way it ages.33The amount of tactile
stimula-tion a rodent pup receives from its mother when she licks it modulates its cortisol response to stress. Those licked more often have more glucocorticoid receptors in the hippocampus and better regulation of hormone levels. Unstimulated pups secrete more cortisol in response to stress; as a result, they exhibit early cell loss in the hippocampus, and display pre-mature memory loss as they grow older.34,35 The
abandoned infants and toddlers reared in the abys-mal state-run orphanages in Romania display abnor-mal patterns of cortisol secretion; circadian rhythm is abolished.36 Adult patients with sustained high
cor-tisol levels for 5 years display a significantly smaller hippocampus when compared with age-matched controls.37
gains, continue to reveal persisting cognitive and emotional defects.38
GOOD BEGINNINGS, GOOD ENDINGS
Let me conclude by extrapolating from pediatrics to adult medicine. Can a head start in childhood and adolescence, the years pediatricians supervise, influ-ence the later years of life? There is a growing liter-ature on the deleterious effects of low birth weight on morbidity and mortality in later life.39 – 41
More-over, there is a strong inverse correlation between the amount of schooling received in youth and rates of dementia in old age; that is, the more years elderly persons have attended school, in their youth, the lower the rates of Alzheimer’s disease in old age. This has been consistently demonstrated in popula-tion studies in countries as varied as the United States, France, Italy, Sweden, Finland, Israel, and China.42
This last finding once again emphasizes the impor-tance of the quality and duration of public education. It is to go well beyond the evidence to suggest a causal relationship between more education in youth and less dementia in old age. But what is to be lost by endorsing universal education as public policy to prevent senility? At the worst, our children will have become more competent citizens before senility be-gins!
CONCLUSION
Whether or not so grand a claim is warranted, pediatricians clearly can promote a head start on brain development. This requires that they fulfill two roles: first, that they provide comprehensive psycho-social care for the children in their practices; and second, that they become advocates for children.
This is not a new message. When Abraham Jacobi43
delivered the first Presidential Address to the Amer-ican Pediatric Society, he stated:
“Every physician is by destiny a ’political being’ in the sense in which the ancients defined the term; that is, a citizen of a com-monwealth, with many rights and great responsibilities. The latter grow with increased power both physical and intellectual. The scientific attainments of the physician and his appreciation of the sources of evil enable him to strike at its root by advising aid and remedy . . . ”
Leon Eisenberg, MD
Harvard Medical School Boston, MA 02115-6019
REFERENCES
1. Eisenberg L. The social construction of the human brain.Am J Psychia-try.1996;152:1563–1575
2. Nelson CA, Bloom FE. Child development and neuroscience.Child Dev. 1997;68:970 –987
3. Rutter M, Plomin R. Opportunities for psychiatry from genetic findings. Br J Psychiatry.1997;171:209 –219
4. West MJ, King AP. Settling nature and nurture into an ontogenetic niche.Dev Psychol.1987;20:549 –562
5. Cutts FT, Robertson SE, Diez-Ortega, JL, Samuel R. Control of rubella and congenital rubella syndrome (CRS) in developing countries, part I. Burden of disease from CRS.Bull World Health Organ.1997;75:55– 66 6. Robertson SE, Cutts FT, Samuel R, Diaz-Ortega J-L. Control of rubella
and congenital rubella syndrome (CRS) in developing countries, part 2. Vaccination against rubella.Bull World Health Organ.1997;75:69 – 80 7. Thomas DR, Salmon RL, King J. Rates of first measles-mumps-rubella
immunisation in Wales (UK).Lancet.1998;351:1927
8. Gangarosa EJ, Galazka AM, Wolfe CR, et al. Impact of anti-vaccine
movements on pertussis control: the untold story.Lancet.1998;351: 356 –361
9. Thomson AM, Billewicz WZ. Nutritional status, maternal physique and reproductive efficiency.Proc Nutr Soc.1963;22:55– 60
10. Donnelly JF, Flowers CE, Creadick RN, Wells HB, Greenberg BG, Surles KB. Maternal, fetal and environmental factors in prematurity.Am J Obstet Gynecol.1964;88:918 –931
11. Birch HG. Health and education of socially disadvantaged children.Dev Med Child Neurol.1968;10:580 –599
12. United Nations.Third Report on the World Nutrition Situation. New York, NY: United Nations; 1997
13. Hardy JP, Shappiro S, Astone NM, Miller TL, Brooks-Gunn J, Hilton SC. Adolescent child bearing revisited: the age of inner-city mothers at delivery is a determinant of their children’s self-sufficiency at age 27 to 33.Pediatrics.1997;100:802– 809
14. Brown S, Eisenberg L.The Best Intentions: Unintended Pregnancy and the Well-Being of Children and Families.Washington, DC: National Academy Press; 1995
15. Sampson RJ. Collective regulation of adolescent misbehavior.J Adol Res. 1997;12:227–244
16. Sampson RJ, Raudenbush SW, Earls F. Neighborhoods and violent crime: a multilevel study of collective efficacy.Science.1997;277:918 –924 17. Jacob F. Evolution and tinkering.Science.1977;196:1161–1166 18. Schatz CJ, Stryker MP. Prenatal tetrodotoxin infusion blocks
segrega-tion of retinogeniculate afferents.Science.1988;242:87– 89
19. Penn AA, Riquelme PA, Feller MB, Shatz CJ. Competition in reticulo geniculate patterning driven by spontaneous activity.Science.1998;279: 2108 –2112
20. Gandelman R, vom Sall FS, Reinisch JM. Contiguity to male fetuses affects morphology and behavior in female mice.Nature. 1977;266: 722–723
21. Schneider ML. The effect of mild stress during pregnancy on birth weight and neuromotor maturation in rhesus monkey infants.Infant Behav Dev.1992;15:389 – 403
22. DeCasper AJ, Spence MJ. Prenatal maternal speech influences new-borns’ perception of speech sounds.Infant Behav Dev.1986;9:133–150 23. Mehler J, Jusczyk PW, Lambertz G. A precursor to language
develop-ment in young infants.Nature.1994;37:292–294
24. Wiesel TN.The Postnatal Development of the Visual Cortex and the Influence of Environment.The 1981 Nobel Prize Lecture. Stockholm, Sweden: Nobel Foundation; 1982
25. Black JE, Isaacs KR, Anderson BJ, et al. Learning causes synaptogenesis, whereas motor activity causes angiogenesis, in cerebellar cortex of adult rats.Proc Natl Acad Sci USA.1990;87:5568 –5572
26. Greenough WT, Black JE. Induction of brain structure by experience: substrates for cognitive development. In: Gunnar MR, Nelson CA, eds. Minnesota Symposia on Child Psychology: Developmental Neuroscience. Hillsdale, NJ: Erlbaum; 1992;24:155–200
27. Schlaug G, Jancke L, Huang Y, et al. Asymmetry in musicians.Science. 1995;267:699 –701
28. Elbert T, Pantev C, Wienbruch C, et al. Increased cortical representation of the fingers of the left hand in string players.Science.1995;270:305–307 29. Sterr A, Muller MM, Elbert T, et al. Changed perceptions in Braille
readers.Nature.1998;391:134 –135
30. Yang TT, Gallen CC, Ramachandran VS, et al. Noninvasive detection of cerebral plasticity in adult human somatosensory cortex.Neuroreport. 1994;5:701–704
31. Ramachandran VS, Rogers-Ramachandran D, Stewart M. Perceptual correlates of massive cortical reorganization. Science. 1992;258: 1159 –1160
32. Mogilner A, Grossman JAI, Ribary V. Somatosensory cortical plasticity in adult humans revealed by magneto-encephalography.Proc Natl Acad Sci USA.1993;90:3593–3597
33. Sapolsky RM. Why stress is bad for your brain. Science. 1996;273: 749 –750
34. Liu D, Diorio J, Tannenbaum B, et al. Maternal care, hippocampal glucocorticoid receptors, and hypothalamic-pituitary-adrenal responses to stress.Science.1997;277:1659 –1662
35. Meaney MJ, Aitken DH, Van Berkel C. RM Effect of neonatal handling on age-related impairments associated with the hippocampus.Science. 1988;239:766 –768
36. Carlson M, Earls F. Psychological and neuroendocrinological sequelae of early social deprivation in institutionalized children in Romania.Ann N Y Acad Sci.1997;807:410 – 428
37. Lupien SJ, deLeon M, de Santi S, et al. Cortisol levels during human aging predict hippocampal atrophy and memory deficits.Nature Neu-rosci.1998;1:69 –73
Devel-opmental catch-up, and deficit, following adoption after severe global early privation.J Child Psychol Psychiatry.1998;39:465– 476
39. Law CM, Shiell AW. Is blood pressure inversely related to birth weight? The strength of evidence from a systematic review of the literature. J Hypertension.1996;14:935–941
40. Rich-Edwards JW, Stamfer MJ, Manson JE, et al. Birth weight and risk of cardiovascular disease in a cohort of women followed-up since 1976. Br Med J.1997;315:396 – 400
41. Martyn CN, Barker DJP, Osmond C. Mothers’ pelvic size, fetal growth, and coronary heart disease in men in the UK. Lancet. 1996;348: 1264 –1268
42. Katzman R. Education and the prevalence of dementia and Alzheimer’s disease.Neurology.1993;43:13–20
43. Jacobi A. The President’s address: the relation of pediatrics to general medicine.Trans Am Pediatr Soc.1893;1:6 –17
Pneumococcal Vaccine: An Update
ABBREVIATION. HIV, human immunodeficiency virus.
S
treptococcus pneumoniae is the most common cause of invasive bacterial infection in children. In addition, the organism causes 30% to 50% of cases of acute otitis media; 24 million visits to pedi-atricians per year in the United States are referable to this diagnosis.1It is also responsible for a significantamount of morbidity and mortality in children and adults in the United States and in other countries. A majority of cases of invasive disease caused by S pneumoniae occur in children ,2 years of age and adults 65 years of age and older.1 The current
23-valent pneumococcal vaccine has been shown to be ineffective in children ,2 years old.2 In addition,
resistance ofS pneumoniaeto penicillin, cephalospo-rins, and other antibiotics has become a serious prob-lem.3 These factors prompted investigations that
have culminated in the development of conjugated polysaccharide-protein vaccines. These new vaccines are similar in design to the already licensed Hae-mophilus influenzae,type b conjugate vaccine. Wide-spread deployment of the conjugateH influenzae vac-cine in 1987 has been followed by a major decrease in morbidity and mortality ofH influenzaeinfection.4
In this commentary, we will review briefly pneu-mococcal infection and discuss the roles of current and future vaccines in the prevention of pneumococ-cal disease.
Nasopharyngeal colonization with S pneumoniae occurs in a majority of children and is most common in children ,4 years of age.2 Colonization may be
followed by acute otitis media and other upper res-piratory infections, as well as by pneumonia. Severe infection, including bacteremia and meningitis, also may occur with significant attendant morbidity and mortality.1Children 6 to 24 months of age are at the
highest risk for pneumococcal infection because pas-sively acquired maternal antibodies are no longer
present. The currently available pneumococcal vac-cine has been ineffective in producing a significant antibody response in children,2 years of age; how-ever, a new conjugate vaccine may be effective in this population.4
CURRENT VACCINE
To date, at least 90 serotypes ofS pneumoniaehave been identified. The current pneumococcal vaccine, licensed in 1983, contains purified, capsular polysac-charide antigen of 23 serotypes ofS pneumoniae(1, 2, 3, 4, 5, 6B, 7F, 8, 9N, 9V, 10A, 11A, 12F, 14, 15B, 17F, 18C, 19A, 19F, 20, 22F, 23F, and 33F). These serotypes are responsible for 85% to 90% of adult infections and virtually 100% of invasive disease in children. The current vaccine replaced a 14-valent vaccine li-censed in the United States in 1977.4
The current 23-valent vaccine had efficacy rates of 61% and 75% in two studies of immunocompetent adults in the prevention of bacteremia and meningi-tis caused by the S pneumoniae serotypes that were incorporated into the vaccine that was used.5,6Butler
and associates5also reported a 57% efficacy rate in all
persons.5 years of age.
Although the current polysaccharide vaccine has been effective in reducing severe disease in the adult population,5 it cannot impact significantly on the
frequency of disease in children ,2 years of age because it does not elicit a significant antibody re-sponse in these children.4 The current vaccine also
has not been shown to be effective in protection against acute otitis media caused by S pneumoniae.2
Current recommendations of the Committee on In-fectious Diseases of the American Academy of Pedi-atrics do not include routine use of the vaccine in children unless they suffer from a specific medical condition that puts them at a higher risk than normal children for severe pneumococcal infection.
CURRENT INDICATIONS
According to the 1997 Red Book,2 pneumococcal
vaccine is indicated in children 2 years of age and older with:
• sickle cell disease
• functional or anatomic asplenia
• nephrotic syndrome or chronic renal failure • immunodeficiency for various reasons, including
organ transplant and prolonged use of systemic steroids
• cerebrospinal fluid leaks and
• human immunodeficiency virus (HIV) infection
In patients with HIV, antibody response may vary with the patient’s immune status.2
Pneumococcal vaccine also is indicated in children with chronic cardiovascular disease, chronic pulmo-nary disease (cystic fibrosis or emphysema, but not asthma), or chronic liver disease (cirrhosis). The American Academy of Pediatrics also recommends vaccination of children .2 years of age who live in special environmental or social situations where the risk of invasive pneumococcal infection or its
com-Received for publication Jan 5, 1999; accepted Jan 5, 1999.
Reprint requests to (R.D.F.) Texas Children’s Hospital, MC 1-3420, 6621 Fannin St, Houston, TX 77030.
DOI: 10.1542/peds.103.5.1031
1999;103;1031
Pediatrics
Leon Eisenberg
Experience, Brain, and Behavior: The Importance of a Head Start
Services
Updated Information &
http://pediatrics.aappublications.org/content/103/5/1031
including high resolution figures, can be found at:
References
http://pediatrics.aappublications.org/content/103/5/1031#BIBL
This article cites 39 articles, 15 of which you can access for free at:
Subspecialty Collections
sub
http://www.aappublications.org/cgi/collection/fetus:newborn_infant_
Fetus/Newborn Infant
l_issues_sub
http://www.aappublications.org/cgi/collection/development:behaviora
Developmental/Behavioral Pediatrics
http://www.aappublications.org/cgi/collection/agency_abcs
Agency ABC's
following collection(s):
This article, along with others on similar topics, appears in the
Permissions & Licensing
http://www.aappublications.org/site/misc/Permissions.xhtml
in its entirety can be found online at:
Information about reproducing this article in parts (figures, tables) or
Reprints
http://www.aappublications.org/site/misc/reprints.xhtml
DOI: 10.1542/peds.103.5.1031
1999;103;1031
Pediatrics
Leon Eisenberg
Experience, Brain, and Behavior: The Importance of a Head Start
http://pediatrics.aappublications.org/content/103/5/1031
located on the World Wide Web at:
The online version of this article, along with updated information and services, is
by the American Academy of Pediatrics. All rights reserved. Print ISSN: 1073-0397.
