Projected cost-effectiveness of pneumococcal conjugate vaccination of healthy infants and young children

Current state of pneumococcal vaccines

Streptococcus pneumoniae is a leading cause of bacterial pneumonia, meningitis, and acute otitis media in children and adults worldwide. According to World Health Organization estimates, at least 1 million children under 5 years of age die each year from pneumococcal pneumonia. The emergence of resistant strains necessitates the development of an effective vaccine with a large serotype coverage. The 11 most common serotypes cause 72-83% of all serious pneumococcal diseases worldwide. Currently marketed 23-valent pneumococcal polysaccharide vaccine provides large serotype coverage and offers a less expensive option. However, it is efficacious only in adults but not in infants. Conjugate vaccines offer a solution by generating immunological memory already at early age. A recently licensed 7-valent conjugate vaccine is immunogenic and efficacious in infants. Its serotype coverage might be sufficient in Europe and North America, but not in Africa, Asia and Oceania. A need exists to develop pneumococcal vaccines with lower cost and larger serotype coverage. Several 11-valent pneumococcal conjugate vaccines are being evaluated in phase I-III trials. This study reviews the current state of pneumococcal problem and pneumococcal vaccines in clinical use.

Pneumococcal vaccination of children

Streptococcus pneumoniae is the most frequent cause of invasive bacterial infection in children younger than 2 years of age, reaching a peak incidence at 6 to 12 months of age. Pneumococci also cause many cases of pneumonia, sinusitis, and otitis media. Incidence rates of invasive infection in children with sickle cell disease, acquired or congenital splenectomy, or human immunodeficiency virus infection are 20- to 100-fold higher than are those of healthy children during the first 5 years of life. Other healthy children, such as those of American Indian, Native Alaskan, or African American descent, also have high rates of invasive infection, and those children enrolled in out-of-home care may have modestly increased risks. Pneumococcal polysaccharide polyvalent vaccines have been available for more than 2 decades but are limited in their usefulness for children because of their inability to induce protective antibody responses in children younger than 2 years of age and lack of immunologic memory. In contrast, pneumococcal protein conjugate vaccines induce presumptive protective responses in infants younger than 6 months, and immunologic memory further enhances responses after booster doses are given. Currently, a single heptavalent pneumococcal protein conjugate vaccine is licensed for use in the United States and is recommended for routine administration to all children, beginning at 2 months of age. It also is recommended for children between 24 and 59 months of age who are at high risk of acquiring invasive disease.

Will genetic testing alter the management of disease caused by infectious agents? A cost-effectiveness analysis of gene-testing strategies for prevention of rheumatic Fever

Cost-effectiveness analysis was done to evaluate the potential health and economic effects of a genetic screening program to identify individuals at risk for rheumatic fever (RF). The current RF prevention strategy was compared with a new, primary prevention strategy involving early genetic testing and intensive prophylaxis to prevent a first attack among individuals at high risk for RF. When analysis of a hypothetical 2000 birth cohort was done from a societal perspective, the prevention strategy involving genetic screening and prophylaxis for high-risk persons reduced the number of RF cases and increased life span at an estimated discounted cost of $7900 per quality-adjusted life-year gained. Genetic screening became the preferred (least expensive) strategy if the test specificity was >/=98%, the annual cost of prophylaxis was <$550, or the annual cost of caring for an individual with severe rheumatic heart disease increased to >$32,000. When used with available antibiotic prophylaxis, genetic testing has the potential to provide a cost-effective strategy for the primary prevention of RF and its sequelae.

Observed costs and health care use of children in a randomized controlled trial of pneumococcal conjugate vaccine

BACKGROUND

Pneumococcal conjugate vaccine for infants has recently been found to be effective for prevention of meningitis, bacteremia, pneumonia and otitis media, but it is more costly than previously introduced vaccines.

AIM

We sought to determine the savings in medical costs through 36 months of life attributable to the use of the vaccine in healthy infants in a large randomized trial.

METHODS

We analyzed the actual medical costs of 36 471 children involved in a randomized trial of heptavalent pneumococcal conjugate vaccine conducted in the Northern California Kaiser Permanente Medical Care Program. The costs of the vaccine and vaccine administration were excluded.

RESULTS

Compared with the control group, the vaccinated group experienced a 2% reduction in clinic related costs [$48; 95% confidence interval (CI), $10 to $83] and a nearly significant 14% reduction in outpatient hospitalization costs ($32; CI -$1 to $66). The savings in total medical costs were 1.2%, but this difference was not significant ($41; CI -$204 to $270). Inpatient hospital costs were highly variable and were responsible for the lack of precision in the difference in total cost. In a post hoc analysis that excluded hospital costs not believed to be potentially pneumococcal related, savings in medical costs were $78 and significant (CI $5 to $158).

CONCLUSIONS

The pneumococcal conjugate vaccine reduced ambulatory care costs in children in the first 36 months of life, but without a larger trial, the magnitude of the savings in total medical costs is uncertain. These results indicate, however, that any medical cost savings that are associated with the vaccine are unlikely to be high enough to offset the cost of the vaccine at its current price.

Vaccination and otitis media

Acute otitis media (AOM) caused by Streptococcus pneumoniae, Haemophilus influenzae or Moraxella catarrhalis may induce specific systemic and/or local immune responses, which may protect from otitis media caused by the same bacteria. However, earlier clinical trials with pneumococcal capsular polysaccharide vaccines have not been successful in preventing AOM. Recently developed pneumococcal polysaccharide-protein conjugates proved immunogenic even in infants, and a heptavalent pneumococcal CRM 197 conjugate vaccine gave a 57% reduction in the number of pneumococcal AOM episodes caused by the vaccine serotypes in infants in Finland. H. influenzae causing AOM is noncapsulated, and like M. catarrhalis, calls for another kind of vaccine development. Suitable vaccine candidates are not yet available but are under development and being tested for immunogenicity and safety. In some trials influenza vaccines have shown protection from AOM during respective viral epidemics. Passive immunoprophylaxis might be an important alternative for immunocompromised children, although this approach has not been successful so far. Mucosal immunization and the advent of DNA and gene technology will open new interesting prospects in the future.

Diagnosis of Streptococcus pneumoniae lower respiratory infection in hospitalized children by culture, polymerase chain reaction, serological testing, and urinary antigen detection

A prospective study of 154 consecutive high-risk hospitalized children with lower respiratory infections was conducted to determine the clinical utility of a pneumolysin-based polymerase chain reaction (PCR) assay compared with blood and pleural fluid cultures and serological and urinary antigen tests to determine the incidence of Streptococcus pneumoniae. Whole blood, buffy coat, or plasma samples from 67 children (44%) tested positive by PCR. Sensitivity was 100% among 11 promptly tested culture-confirmed children and specificity was 95% among control subjects. Age, prior oral antibiotic therapy, and pneumococcal nasopharyngeal colonization did not influence PCR results, whereas several surrogates of disease severity were associated with positive tests. Although serological and urinary antigen tests had comparable sensitivity, specificity varied among infected children, and statistical agreement among all assays was limited. These findings support the use of PCR tests to evaluate the protective efficacy of pneumococcal conjugate vaccines and to identify promptly children with pretreated or nonbacteremic pneumococcal lower respiratory infections.

Future vaccines: recent advances and future prospects

The 20th century has witnessed the introduction of over 20 vaccines that prevent or even conquer diseases such as smallpox, polio, and measles. The continued threat of infectious diseases demands the creation of many more vaccines, especially against common respiratory and gastrointestinal pathogens. Thanks to recent advances in molecular biology, immunology, and adjuvant technology, the next decade likely will bring a vaccine for HIV/AIDS also. We enter the 21st century with a tempered optimism, proud of past achievements, but mindful of the challenges that lie ahead.

Comparative cost effectiveness of varicella, hepatitis A, and pneumococcal conjugate vaccines

BACKGROUND

Several state and local U.S. governments are considering making varicella, hepatitis A, and/or pneumococcal conjugate vaccination conditions of day care or school entry. These requirements will likely be issued sequentially, because simultaneous mandates exacerbate budget constraints and complicate communication with parents and providers. Cost-effectiveness assessments should aid the establishment of vaccination priorities, but comparing results of published studies is confounded by their dissimilar methods.

METHODS

We reviewed U.S. cost-effectiveness studies of childhood varicella, hepatitis A, and pneumococcal conjugate vaccines and identified four providing data required to standardize methods. Vaccination, disease treatment, and work-loss costs were estimated from original study results and current prices. Estimated life-years saved were derived from original study results, epidemiological evidence, and alternative procedures for discounting to present values.

RESULTS

Hepatitis A vaccine would have the lowest health system costs per life-year saved. Varicella vaccine would provide the greatest reduction in societal costs, mainly through reduced parent work loss. Pneumococcal conjugate vaccine would cost twice the amount of varicella and hepatitis A vaccines combined and be less cost effective than the other vaccines.

CONCLUSIONS

Hepatitis A and varicella vaccines, but not pneumococcal conjugate vaccine, meet or exceed conventional standards of cost effectiveness.

"Reverse engineering" a formulary selection algorithm to determine the economic value of pentavalent and hexavalent combination vaccines

INTRODUCTION

Combination vaccines with overlapping, noncomplementary components are being introduced to reduce the number of separate injections required to immunize children. A vaccine selection algorithm using operations research techniques was developed as a tool for vaccine purchasers to assemble formularies of monovalent and combination vaccines that would satisfy the recommended immunization schedule. The algorithm weighs distinguishing features of economic consequence among competing vaccines to achieve the lowest overall cost to payers and/or to society for immunization. This method was adapted here to solve for the purchase price of several hypothetical future pentavalent and hexavalent combination vaccines that would permit each to "win" a place in such a lowest cost formulary.

METHODS

Integer programming and an iterative bisection search method determined the maximum "inclusion price" of 4 vaccines not licensed in the United States as of September, 2001 [diphtheria-tetanus-acellular pertussis (DTPa)-Haemophilus influenzae type b (HIB)-hepatitis B (HBV), DTPa-HIB-inactivated polio vaccine (IPV), DTPa-HBV-IPV and DTPa-HIB-HBV-IPV], in competition with 15 existing formulations of licensed vaccines for these diseases at their March, 2000, federal contract discount prices. Both 5-visit and 6-visit scenarios were studied. Different preparation costs were assigned to lyophilized powder ($1.50), liquid ($0.75) and prefilled-syringe ($0.25) formulations/packaging. Injection costs were varied stepwise from $5 through $45 for each dose administered, shifting from a payer's to a societal perspective.

RESULTS

Overall inclusion prices (maximum price for each candidate vaccine to be included in a lowest cost formulary) ranged from $9 to $129 per dose depending on cost assumptions and usage frequency (values would be higher if competing against private-sector vaccine prices). The range was $27 to $68 per dose for DTPa-HIB-HBV, at optimal utilization to avoid extra vaccination. Similarly, as injection costs varied from $5 to $45, DTPa-HIB-IPV ranged from $28 to $75. With the same assumptions, DTPa-HBV-IPV would earn a place in a best value formulary at prices from $35 to $76. As expected the inclusion prices for hexavalent DTPa-HIB-HBV-IPV, $40 to $123, were higher (reflecting more economic value) than for pentavalents. When the assumed injection costs rose to > or = $8, the more expensive HIB-HBV and DTPa-HIB tended to appear in lowest cost formularies, because their cost premium over separate monovalent and trivalent products was outweighed by the savings from one fewer injection.

CONCLUSION

Reverse engineering the vaccine selection algorithm provides a tool to demonstrate the economic value of new combination vaccines and to make pricing decisions.

Management of febrile children in the age of the conjugate pneumococcal vaccine: a cost-effectiveness analysis

OBJECTIVES

The optimal practice management of highly febrile 3- to 36-month-old children without a focal source has been controversial. The recent release of a conjugate pneumococcal vaccine may reduce the rate of occult bacteremia and alter the utility of empiric testing and treatment. The objective of this study was to determine the cost-effectiveness of 6 different management strategies of febrile 3- to 36-month-old children at current and declining rates of occult pneumococcal bacteremia.

METHODS

A cost-effectiveness (CE) analysis was performed to compare the strategies of "no work-up," "clinical judgment," "blood culture," "blood culture + treatment," "complete blood count (CBC) + selective blood culture and treatment," and "CBC and blood culture + selective treatment." A hypothetical cohort of 100 000 children who were 3 to 36 months of age and had a fever of >/=39 degrees C and no source of infection was modeled for each strategy. Our main outcome measures were cases of meningitis prevented, life-years saved compared with "no work-up," total cost (1999 dollars), and incremental CE ratios.

RESULTS

When compared with "no work-up," the strategy of "CBC + selective blood culture and treatment" using a white blood cell (WBC) cutoff of 15 x 10(9)/L prevents 48 cases of meningitis, saves 86 life-years per 100 000 patients, and is less costly at the current rate of bacteremia (1.5%). Using the strategy of "CBC + selective blood culture and treatment" with a lower WBC cutoff of 10 x 10(9)/L costs an additional $72 300 per life-year saved. If the rate of bacteremia declines to 0.5%, then the incremental CE ratio of "clinical judgment" compared with "no work-up" is $38 000 per life-year saved; however, strategies that include empiric testing or treatment result in CE ratios greater than $300 000 per life-year saved.

CONCLUSIONS

"CBC + selective blood culture and treatment" using a WBC cutoff of 15 x 10(9)/L is cost-effective at the current rate of pneumococcal bacteremia. If the rate of occult bacteremia falls below 0.5% with widespread use of the conjugate pneumococcal vaccine, then strategies that use empiric testing and treatment should be eliminated.

Efficacy of pneumococcal conjugate vaccines and their effect on carriage and antimicrobial resistance

Pneumococcal conjugate vaccines have shown a high degree of success in preventing pneumococcal bacteraemia in children. They also reduce the acquisition of carriage of vaccine serotypes in the nasopharynx, and reduce otitis media caused by those serotypes. Non-vaccine serotypes, which can colonise vaccinated infants, are associated with otitis media in these children and lower the overall effectiveness of the vaccine to this disorder. Longer term studies, however, could show that immunised children develop immunity to a broad range of pneumococcal serotypes at a younger age than non-immunised children. Preliminary data suggest that these vaccines could reduce the burden of radiologically confirmed pneumonia. Pneumococcal conjugate vaccines interrupt the transmission of antibiotic-resistant pneumococci and thus decrease the burden of antibiotic resistance in immunised children and in their contacts. Studies are underway to assess conjugate vaccine efficacy against invasive disease, pneumonia, and all-cause mortality in developing countries, and to assess the potential use of these vaccines in adults.

Neonatal jaundice, animal-induced injuries, and immunizations

The authors describe recent developments in three areas of pediatrics commonly encountered by the office practitioner. First, clinical assessment of jaundice remains critically important as "early discharge" of newborns continues. Practitioners constantly balance clinical realities with an evidence-based approach in the management and follow-up of neonatal hyperbilirubinemia. Second, given the frequent exposure of children to animals, a thorough understanding of animal bites, pet-borne infections, and rabies prophylaxis is essential for every pediatrician. Finally, immunization status remains one of our leading health indicators. Recent changes in the routine immunization schedule and a renewed emphasis on vaccine safety provide insight into the future direction of vaccinology.

Cost-effectiveness analysis of an intranasal influenza vaccine for the prevention of influenza in healthy children

OBJECTIVE

Intranasal influenza vaccine has proven clinical efficacy and may be better tolerated by young children and their families than an injectable vaccine. This study determined the potential cost-effectiveness (CE) of an intranasal influenza vaccine among healthy children.

METHODS

We conducted a CE analysis of data collected between 1996 and 1998 during a prospective 2-year efficacy trial of intranasal influenza vaccine, supplemented with data from the literature. The CE analysis included both direct and indirect costs. We enrolled 1602 healthy children aged 15 to 71 months in year 1, 1358 of whom were enrolled in year 2. One or 2 doses of intranasal influenza vaccine or placebo were administered to measure the cost per febrile influenza-like illness (ILI) day avoided.

RESULTS

During the 2-year study period, vaccinated children had an average of 1.2 fewer ILI fever days/child than unvaccinated children. In an individual-based vaccine delivery scenario with vaccine given twice in the first year and once each year thereafter at an assumed base case total cost of $20 for the vaccine and its administration (ie, per dose), CE was approximately $30/febrile ILI day avoided. CE ranged from $10 to $69/febrile ILI day avoided at $10 to $40/dose, respectively. In a group-based delivery scenario, vaccination was cost saving compared with placebo and remained so if vaccine cost was <$28 (the break-even price per dose). In the individual-based scenario, vaccination was cost saving if vaccine cost was <$5. In this scenario, nearly half of lost productivity in the vaccine group was attributable to vaccine visits, which overshadowed the relatively modest savings in ILI-associated costs averted.

CONCLUSIONS

Routine use of intranasal influenza vaccine among healthy children may be cost-effective and may be maximized by using group-based vaccination approaches. cost-effectiveness, influenza, vaccine, children.

Pneumococcal vaccination: current and future issues

Infection with Streptococcus pneumoniae remains a major global health burden meaning the development of effective vaccines is urgently needed. The current 23-valent polysaccharide vaccine has been shown to prevent pneumococcal pneumonia in immunocompetent young adults, but not in elderly persons. However, in prevention of invasive pneumococcal disease, the vaccine is efficacious in the elderly and may also be effective in some groups of immunocompromised patients. The polysaccharide vaccine is, therefore, recommended in all older (> or = 55-65 yrs of age) adults and in young children (>2 yrs of age) who have a high risk for pneumococcal disease. Revaccination can be safely performed and is recommended 5 yrs after the first dose. In children <2 yrs of age, the new polysaccharide-protein conjugate vaccines, including 7-11 serotypes, seem to be effective in the prevention of invasive disease, severe pneumonia and serotype-specific (and vaccine-related types) otitis media. The low serotype coverage, need for repeated doses, and high price, may decrease the usefulness of the new conjugates. However, the included serotypes correspond to those most often associated with penicillin resistance and vaccination is, therefore, a possible tool in limiting the spread of antibiotic-resistant pneumococci.

Bacteriology of acute otitis media in a cohort of Finnish children followed for the first two years of life

BACKGROUND

Timely information on the bacteriology of primary, noncomplicated acute otitis media (AOM) may today be needed more than ever, because of the increasing antimicrobial resistance of its major bacterial causes and because of the potential of new pneumococcal and other bacterial vaccines for prevention of AOM.

METHODS

The study followed 329 children from 2 to 24 months of age at scheduled healthy visits and sick visits at the study clinic. Whenever AOM was diagnosed during the follow-up, myringotomy was performed and middle ear fluid was aspirated for bacterial culture.

RESULTS

At least one middle ear fluid sample was available from 772 AOM events; Streptococcus pneumoniae (Pnc) was isolated in 201 (26%), Moraxella catarrhalis (Mc) in 177 (23%) and Haemophilus influenzae (Hi) in 174 events (23%). The incidence of Pnc AOM peaked at 12 months of age, whereas the incidence of Mc AOM showed the first peak at 6 months and Hi AOM at 20 months. Pnc AOM showed less prominent seasonality in occurrence than Mc and Hi AOM. Hi was a rare cause of the first 2 AOM episodes (13%) but became increasingly common from the third episode on (32% on average).

CONCLUSIONS

Pnc, Mc and Hi were almost equally common findings in AOM. Pnc seems to be the most pathogenic of these three, the role of Mc is increasing and Hi is clearly associated with recurrent AOM.

A new conjugate vaccine against pneumococcal disease

Streptococcus pneumoniae (pneumococcus) is a major cause of morbidity and mortality, particularly among infants and children. Pneumococcal 7-valent conjugate vaccine (PNCRM7) is the first conjugate vaccine known to prevent most invasive pneumococcal disease in infants and children. PNCRM7, which has a favorable safety profile, provides protection against invasive disease caused by antibiotic-resistant strains of S. pneumoniae, and the vaccine has demonstrated a significant impact on otitis media recurrence. Routine immunization with this vaccine should substantially reduce morbidity and mortality and improve the quality of life for infants, children, and their families.

The prevention of pneumococcal disease by vaccines: promises and challenges

This article reviews the epidemiology of pneumococcal disease and the current data on pneumococcal vaccine efficacy, discusses promising new data regarding development of new protein-conjugate pneumococcal vaccines, and addresses controversies surrounding the widespread population use of these vaccines. Armed with these data, physicians, nurses, third party payers, and health care systems should develop systems and eliminate unintentional barriers so as to achieve widespread use of these life-saving vaccines. As history has demonstrated to us, control of pneumococcal disease is highly unlikely to occur from heavy investments in newer and ever more expensive antibiotics, as opposed to better methods of preventing disease through the rational and widespread population use of vaccines.

Pneumococcal conjugate vaccine

Pneumococcal infections account for a significant proportion of bacterial infections in infants and children. The growing threat from pneumococci resistant to penicillin and other antimicrobials has led to increased pressure for the development of an effective vaccine. The only vaccine available until recently, a purified polysaccharide vaccine, is limited in that it fails to induce adequate and long-lasting immunity in infants under 2 years of age, the age group most at risk from this disease. Polysaccharide antigens conjugated to certain proteins induce effective immunity with a rapid response to subsequent infection or antigen challenge. The success of the protein-conjugated haemophilus influenzae vaccine supports the strategy of protein-conjugated polysaccharide vaccines. Currently, published trials of conjugated pneumococcal vaccines have shown the effectiveness and safety of these vaccines. Conjugate vaccines also provide protection against otitis media and may eliminate nasopharyngeal carriage of this organism. Widespread use of this vaccine is both cost effective and safe.

Streptococcus pneumoniae: new tools for an old pathogen

The pneumococcus is one of the longest-known pathogens. It has been instrumental to our understanding of biology in many ways, such as in the discovery of the Gram strain and the identification of nucleic acid as the hereditary material. Despite major advances in our understanding of pneumococcal pathogenesis, the need for vaccines and antibiotics to combat this pathogen is still vital. Genomics is beginning to uncover new virulence factors to advance this process, and it is enabling the development of DNA chip technology, which will permit the analysis of gene expression in specific tissues and in virulence regulatory circuits.

Conjugate pneumococcal vaccines for non-indigenous children in Australia

Childhood pneumococcal disease is associated with substantial morbidity and mortality, but total disease burden is more difficult to measure than for invasive disease caused by Haemophilus influenzae type b (Hib). A safe, effective seven-valent conjugate pneumococcal vaccine will be available in Australia by early 2001, and will certainly be indicated for high-risk groups and purchased in the private sector, as was Hib vaccine. The status of this vaccine on the Australian Standard Vaccination Schedule will require more detailed consideration of the burden and serotype distribution of pneumococcal disease in Australian children and the vaccine's likely cost-effectiveness. Postmarketing surveillance will be particularly important.

Impact of Antimicrobial Resistance on the Treatment of Invasive Pneumococcal Infections

Infectious diseases, such as pneumococcal pneumonia, which were almost invariably lethal in the pre-antibiotic era, caused radically less mortality with the advent of antimicrobial chemotherapy. However, the use, misuse, and abuse of these agents have led to the emergence of antimicrobial resistance. In the past, pneumococci were all exquisitely sensitive to penicillin G. By the late 1960s, penicillin-nonsusceptible Streptococcus pneumoniae (PNSP) was being described. Since then, this problem has achieved epidemic proportions in many areas of the world, including the United States. Many experts no longer consider penicillin an acceptable therapy for patients suspected of having invasive pneumococcal disease, especially if the central nervous system (CNS) is involved. Recommendations for therapy are based on theoretical concerns, in vitro susceptibility testing, animal data, and a few, scattered reports of penicillin failure in patients with invasive disease.

Changing Epidemiology of Bacterial Meningitis in the United States

Bacterial meningitis is an important cause of morbidity and mortality in the United States and throughout the world. Over the past 20 years, there have been significant changes in the epidemiology of bacterial meningitis. The most important change is the decrease in the frequency of Haemophilus influenzae type b as the most common etiologic agent of bacterial meningitis, since the H. influenzae type b conjugate vaccine was introduced. Streptococcccus pneumoniae is now the major cause of bacterial meningitis in the US and bacterial meningitis is now a disease predominantly of adults, rather than of infants and children. Emergence of antimicrobial resistance in S. pneumoniae has also altered the approach to antimicrobial therapy in patients with pneumococcal meningitis, indicating the need to use preventive strategies to reduce the frequency of this serious infection. Recent licensure of the heptavalent pneumococcal conjugate vaccine will likely decrease the overall incidence of pneumococcal meningitis.

American Academy of Pediatrics. Committee on Infectious Diseases. Technical report: prevention of pneumococcal infections, including the use of pneumococcal conjugate and polysaccharide vaccines and antibiotic prophylaxis

Pneumococcal infections are the most common invasive bacterial infections in children in the United States. The incidence of invasive pneumococcal infections peaks in children younger than 2 years, reaching rates of 228/100,000 in children 6 to 12 months old. Children with functional or anatomic asplenia (including sickle cell disease [SCD]) and children with human immunodeficiency virus infection have pneumococcal infection rates 20- to 100-fold higher than those of healthy children during the first 5 years of life. Others at high risk of pneumococcal infections include children with congenital immunodeficiency; chronic cardiopulmonary disease; children receiving immunosuppressive chemotherapy; children with immunosuppressive neoplastic diseases; children with chronic renal insufficiency, including nephrotic syndrome; children with diabetes; and children with cerebrospinal fluid leaks. Children of Native American (American Indian and Alaska Native) or African American descent also have higher rates of invasive pneumococcal disease. Outbreaks of pneumococcal infection have occurred with increased frequency in children attending out-of-home care. Among these children, nasopharyngeal colonization rates of 60% have been observed, along with pneumococci resistant to multiple antibiotics. The administration of antibiotics to children involved in outbreaks of pneumococcal disease has had an inconsistent effect on nasopharyngeal carriage. In contrast, continuous penicillin prophylaxis in children younger than 5 years with SCD has been successful in reducing rates of pneumococcal disease by 84%. Pneumococcal polysaccharide vaccines have been recommended since 1985 for children older than 2 years who are at high risk of invasive disease, but these vaccines were not recommended for younger children and infants because of poor antibody response before 2 years of age. In contrast, pneumococcal conjugate vaccines (Prevnar) induce proposed protective antibody responses (>.15 microg/mL) in >90% of infants after 3 doses given at 2, 4, and 6 months of age. After priming doses, significant booster responses (ie, immunologic memory) are apparent when additional doses are given at 12 to 15 months of age. In efficacy trials, infant immunization with Prevnar decreased invasive infections by >93% and consolidative pneumonia by 73%, and it was associated with a 7% decrease in otitis media and a 20% decrease in tympanostomy tube placement. Adverse events after the administration of Prevnar have been limited to areas of local swelling or erythema of 1 to 2 cm and some increase in the incidence of postimmunization fever when it is given with other childhood vaccines. Based on data in phase 3 efficacy and safety trials, the US Food and Drug Administration has provided an indication for the use of Prevnar in children younger than 24 months.

Neonatal jaundice, animal-induced injuries, and immunizations

The authors describe current investigation and most recent developments in three areas of pediatrics commonly faced by the office practitioner. The impetus of earlier newborn discharge places increased emphasis on pediatricians to accurately predict clinically significant jaundice. A better understanding of the pathophysiology of breastfeeding and breast milk jaundice, and the realization that Gilbert's syndrome may play a greater role in neonatal jaundice, only help confirm that the story of neonatal jaundice is still unfolding. Animal (particularly canine) bite injuries continue to be the most common animal-induced injuries, and a thorough review of appropriate antibiotic treatment and rabies prophylaxis guidelines are essential for the pediatric practitioner. During the past year, several major changes involving the use of rotavirus, pneumococcal, polio, meningococcal, and hepatitis A vaccines have taken place, which will have marked impact not only on pediatric office practice, but also on society as a whole.