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Vaccine Jul 2016Protein-polysaccharide conjugate vaccines such as Haemophilus influenzae type b (Hib), meningococcal, and pneumococcal vaccine, induce immunological memory and longer... (Meta-Analysis)
Meta-Analysis Review
The impact of administration of conjugate vaccines containing cross reacting material on Haemophilus influenzae type b antibody responses in infants: A systematic review and meta-analysis of randomised controlled trials.
BACKGROUND
Protein-polysaccharide conjugate vaccines such as Haemophilus influenzae type b (Hib), meningococcal, and pneumococcal vaccine, induce immunological memory and longer lasting protection than plain polysaccharide vaccines. The most common proteins used as carriers are tetanus toxoid (TT) and cross reacting material-197 (CRM), a mutant form of diphtheria toxoid. CRM conjugate vaccines have been reported to suppress antibody responses to co-administered Hib-TT vaccine.
METHODS
We conducted a systematic review and meta-analysis of randomised controlled trials in which infants were randomised to receive meningococcal or pneumococcal conjugate vaccines along with Hib-TT. Trials of licensed vaccines with different carrier proteins were included for group C meningococcal (MenC), quadrivalent ACWY meningococcal (MenACWY), and pneumococcal vaccines.
RESULTS
Twenty-three trials were included in the meta-analyses. Overall, administration of MenC-CRM in a 2 or 3 dose schedule resulted in a 45% reduction in Hib antibody concentrations (GMR 0.55, 95% CI 0.49-0.62). MenACWY-CRM boosted Hib antibody responses by 22% (GMR 1.22, 95% CI 1.06-1.41) whilst pneumococcal CRM conjugate vaccines had no impact on Hib antibody responses (GMR 0.91, 95% CI 0.68-1.22).
CONCLUSIONS
The effect of CRM protein-polysaccharide conjugate vaccines on Hib antibody responses varies greatly between vaccines. Co-administration of a CRM conjugate vaccine can produce either positive or negative effects on Hib antibody responses. These inconsistencies suggest that CRM itself may not be the main driver of variability in Hib responses, and challenge current perspectives on this issue.
Topics: Antibodies, Bacterial; Antibody Formation; Bacterial Proteins; Cross Reactions; Haemophilus influenzae type b; Humans; Infant; Meningococcal Vaccines; Neisseria meningitidis, Serogroup C; Pneumococcal Vaccines; Randomized Controlled Trials as Topic; Vaccines, Conjugate
PubMed: 27349840
DOI: 10.1016/j.vaccine.2016.06.038 -
The Cochrane Database of Systematic... Feb 2016People affected with sickle cell disease are at high risk of infection from Haemophilus influenzae type b. Before the implementation of Haemophilus influenzae type b... (Review)
Review
BACKGROUND
People affected with sickle cell disease are at high risk of infection from Haemophilus influenzae type b. Before the implementation of Haemophilus influenzae type b conjugate vaccination in high-income countries, this was responsible for a high mortality rate in children under five years of age. In African countries, where coverage of this vaccination is still extremely low, Haemophilus influenzae type b remains one of the most common cause of bacteraemias in children with sickle cell disease. The increased uptake of this conjugate vaccination may substantially improve the survival of children with sickle cell disease.
OBJECTIVES
The primary objective was to determine whether Haemophilus influenzae type b conjugate vaccines reduce mortality and morbidity in children and adults with sickle cell disease.The secondary objectives were to assess the following in children and adults with sickle cell disease: the immunogenicity of Haemophilus influenzae type b conjugate vaccines; the safety of these vaccines; and any variation in effect according to type of vaccine, mode of administration (separately or in combination with other vaccines), number of doses, and age at first dose.
SEARCH METHODS
We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also contacted relevant pharmaceutical companies to identify unpublished trials.Date of last search: 23 November 2015.
SELECTION CRITERIA
All randomised and quasi-randomised controlled trials comparing Haemophilus influenzae type b conjugate vaccines with placebo or no treatment, or comparing different types of Haemophilus influenzae type b conjugate vaccines in people with sickle cell disease.
DATA COLLECTION AND ANALYSIS
No trials of Haemophilus influenzae type b conjugate vaccines in people with sickle cell disease were found.
MAIN RESULTS
There is an absence of evidence from randomised controlled trials relating to the subject of this review.
AUTHORS' CONCLUSIONS
There has been a dramatic decrease in the incidence of invasive Haemophilus influenzae type b infections observed in the post-vaccination era in people with sickle cell disease living in high-income countries. Therefore, despite the absence of evidence from randomised controlled trials, it is expected that Haemophilus influenzae type b conjugate vaccines may be useful in children affected with sickle cell disease, especially in African countries where there is a high prevalence of the disease. The implementation of childhood immunisation schedules, including universal Haemophilus influenzae type b conjugate vaccination, may substantially improve the survival of children with sickle cell disease living in low-income countries. We currently lack data to evaluate the potential effect of Haemophilus influenzae type b vaccination among unvaccinated adults with sickle cell disease. Further research should assess the optimal Hib immunisation schedule in children and adults with sickle cell disease.
Topics: Anemia, Sickle Cell; Bacterial Capsules; Haemophilus Infections; Haemophilus Vaccines; Haemophilus influenzae type b; Humans; Vaccines, Conjugate
PubMed: 26881484
DOI: 10.1002/14651858.CD011199.pub2 -
Southern Medical Journal Jan 2016Vaccines are among the greatest achievements in biomedicine and public health. Yet for a variety of reasons, some vaccine-preventable illnesses have experienced... (Review)
Review
Vaccines are among the greatest achievements in biomedicine and public health. Yet for a variety of reasons, some vaccine-preventable illnesses have experienced resurgences during the last decade. As such, there is a particular need for pediatric providers to be aware of the newest guidelines for vaccination administration to provide consistent and evidence-based recommendations and thoughtful reassurance to families. We aimed to enhance providers' understanding of pediatric vaccinations by highlighting recent changes in vaccination guidelines and addressing common knowledge gaps. This is not a comprehensive list or systematic review of vaccination recommendations. Rather, we present a collection of new developments and misconceptions we have found particularly relevant in our own experience in providing vaccination education at a training institution.
Topics: Acetaminophen; Adolescent; Bacterial Infections; Child; Child, Preschool; Family; Female; Guidelines as Topic; Haemophilus influenzae type b; Heterotaxy Syndrome; Humans; Immunity, Herd; Infant; Male; Tetanus; Tetanus Toxoid; Uterine Cervical Neoplasms; Vaccination; Vaccines, Combined; Whooping Cough
PubMed: 26741872
DOI: 10.14423/SMJ.0000000000000399 -
Chinese Medical Journal Oct 2015Noncystic fibrosis (non-CF) bronchiectasis remains as a common health problem in Asia. Pathogens' distribution in airways of patients with non-CF bronchiectasis is... (Review)
Review
OBJECTIVE
Noncystic fibrosis (non-CF) bronchiectasis remains as a common health problem in Asia. Pathogens' distribution in airways of patients with non-CF bronchiectasis is important for doctors to make right decision.
DATA SOURCES
We performed this systematic review on the English language literatures from 1966 to July 2014, using various search terms included "pathogens" or "bacteria" or "microbiology" and "bronchiectasis" or "non-cystic fibrosis bronchiectasis" or "non-CF bronchiectasis" or "NCFB."
STUDY SELECTION
We included studies of patients with the confirmed non-CF bronchiectasis for which culture methods were required to sputum or bronchoalveolar lavage fluid (BALF). Weighted mean isolation rates for Haemophilus influenzae, Pseudomonas aeruginosa, Streptococcus pneumoniae, Stapylococcus aureus, Moxarella catarrhails were compared according to different methodology.
RESULTS
The total mean bacterial culture positive rates were 63%. For studies using sputum samples, the mean positive culture rates were 74%. For studies using BALF alone or BALF and sputum, it was 48%. The distributions of main bacterial strains were 29% for H. influenzae, 28% for P. aeruginosa, 11% for S. pneumoniae, 12% for S. aureus, and 8% for M. catarrhails with methodology of sputum. Meanwhile, the bacterial distributions were 37% for H. influenzae, 8% for P. aeruginosa, 14% for S. pneumoniae, 5% for S. aureus, and 10% for M. catarrhails with methodology of BALF alone or BALF and sputum. Analysis of the effect of different methodology on the isolation rates revealed some statistically significant differences.
CONCLUSIONS
H. influenzae accounted for the highest percentage in different methodology. Our results suggested that the total positive culture rates and the proportion of P. aeruginosa from sputum and BALF specimens had significant differences, which can be used in further appropriate recommendations for the treatment of non-CF bronchiectasis.
Topics: Bronchiectasis; Bronchoalveolar Lavage Fluid; Haemophilus influenzae; Humans; Pseudomonas aeruginosa; Sputum
PubMed: 26481748
DOI: 10.4103/0366-6999.167360 -
The Cochrane Database of Systematic... Jun 2015Infections during pregnancy confers increased risk of maternal and perinatal morbidity and mortality. However, the case for advocating Haemophilus influenzae type B... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Infections during pregnancy confers increased risk of maternal and perinatal morbidity and mortality. However, the case for advocating Haemophilus influenzae type B (Hib) and viral Influenza vaccinations in pregnancy is still debatable.
OBJECTIVES
To assess the impact of Hib and viral Influenza vaccinations during pregnancy on maternal, neonatal and infant health outcomes compared to placebo/control.
SEARCH METHODS
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (29 January 2015) and reference lists of retrieved studies.
SELECTION CRITERIA
All randomised controlled clinical trials (including cluster-randomised trials) and quasi-randomised trials evaluating Hib or viral influenza vaccination during pregnancy compared with no vaccination or placebo.
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed trials for inclusion, risk of bias and extracted data. Data were checked for accuracy.
MAIN RESULTS
Two trials were included this review. One (involving 213 women and 213 neonates) evaluated the impact of Hib vaccination during pregnancy and the other study (involving 2116 women and 2049 neonates) evaluated the impact of viral influenza vaccination during pregnancy. Overall, the HiB vaccination trial was judged to be at 'high risk of bias' due to inadequate randomisation while the other trial was judged to be at 'low risk of bias'. Hib vaccination during pregnancy versus placeboOne trial involving 213 women and 213 neonates evaluating the impact of Hib vaccination during pregnancy was included under this comparison. The study did not report on any of this review's prespecified primary outcomes (including mortality, respiratory tract infection and sepsis) or secondary outcomes (including adverse events) except preterm delivery. There was no clear difference between the Hib vaccination and placebo control groups in terms of preterm delivery (risk ratio (RR) 1.28, 95% confidence interval (CI) 0.12 to 13.86, one study, 213 participants), fetal distress (RR 1.23, 95% CI 0.67 to 2.26, one study, 213 infants), intubation (RR 1.03, 95% CI 0.55 to 1.95, one study, 213 infants) and neonatal jaundice (RR 1.01, 95% CI 0.52 to 1.97, one study, 213 infants). We could not grade the evidence for quality due to lack of outcome data. Viral influenza vaccination during pregnancy versus placeboOne trial involving 2116 women and 2049 infants evaluating the impact of trivalent inactivated influenza vaccine (IIV3) during pregnancy was included under this comparison.There was no clear difference between the viral influenza and placebo control group in terms of most of this review's primary outcomes: maternal death (RR 4.96, 95% CI 0.24 to 103.24, moderate quality evidence), infant death up to 175 days after birth (RR 0.71, 95% CI 0.37 to 1.37, moderate quality evidence), perinatal death (stillbirth and death in the first week of life) (RR 1.32, 95% CI 0.73 to 2.38, moderate quality evidence), influenza-like illness in women (RR 0.96, 95% CI 0.79 to 1.16) or their babies (RR 1.02, 95% CI 0.94 to 1.09), any respiratory illness in women (RR 0.97, 95% CI 0.91 to 1.04, high quality evidence) or their babies (RR 1.01, 95% CI 0.95 to 1.07, high quality evidence). There were also no clear differences between vaccination and placebo control groups in terms of maternal hospitalisation for any infection (RR 2.27, 95% CI 0.94 to 5.49; 2116 women, moderate quality evidence), and neonatal hospitalisation for sepsis (RR 1.60, 95% CI 0.73 to 3.50; 2049 infants, moderate quality evidence). However, viral influenza vaccination during pregnancy was associated with a reduction in reverse-transcriptase-polymerase-chain-reaction (RT-PCR) confirmed influenza among infants (RR 0.51, 95% CI 0.30 to 0.88, one study, 2049 infants) and women (RR 0.50, 95% CI 0.29 to 0.86, one study, 2116 women).In terms of this review's secondary outcomes, there were no clear differences in terms of the impact on pregnancy outcomes (miscarriage, preterm labour and stillbirth), hospitalisation for respiratory infection among women and infants. Similarly, there was no difference between the viral influenza vaccine and placebo control groups in terms of any adverse systemic reactions.
AUTHORS' CONCLUSIONS
There is limited evidence (from one small trial at a high risk of bias) on the effectiveness on Hib during pregnancy for improving maternal, neonatal and infant health outcomes.Evidence from one large high quality trial on the effectiveness of viral influenza vaccine during pregnancy suggests reduced RT-PCR confirmed influenza among women and their babies, suggesting the potential of this strategy for scale up but further evidence from varying contexts is required.Further trials for both Hib and viral influenza vaccines with appropriate study designs and suitable comparison groups are required. There are currently two 'ongoing' studies - these will be incorporated into the review in future updates.
Topics: Adolescent; Adult; Female; Haemophilus influenzae type b; Humans; Infant, Newborn; Influenza Vaccines; Influenza, Human; Pregnancy; Pregnancy Complications, Infectious; Pregnancy Outcome; Randomized Controlled Trials as Topic; Vaccination; Vaccines, Inactivated
PubMed: 26059051
DOI: 10.1002/14651858.CD009982.pub2 -
The Cochrane Database of Systematic... Sep 2014Chronic bronchitis and chronic obstructive pulmonary disease (COPD) are serious conditions in which patients are predisposed to viral and bacterial infections resulting... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Chronic bronchitis and chronic obstructive pulmonary disease (COPD) are serious conditions in which patients are predisposed to viral and bacterial infections resulting in potentially fatal acute exacerbations. COPD is defined as a lung disease characterised by obstruction to lung airflow that interferes with normal breathing. Antibiotic therapy has not been particularly useful in eradicating bacteria such as non-typeable Haemophilus influenzae (NTHi) because they are naturally occurring flora of the upper respiratory tract in many people. However, they can cause opportunistic infection. An oral NTHi vaccine has been developed to protect against recurrent infective acute exacerbations in chronic bronchitis.
OBJECTIVES
To assess the effectiveness of an oral, whole-cell, non-typeable H. influenzae (NTHi) vaccine in protecting against recurrent episodes of acute exacerbations of chronic bronchitis and COPD in adults. To assess the effectiveness of NTHi vaccine in reducing NTHi colonising the respiratory tract during recurrent episodes of acute exacerbations of COPD.
SEARCH METHODS
We searched the following databases: CENTRAL (2014, Issue 6), MEDLINE (1946 to July week 3, 2014), EMBASE (1974 to July 2014), CINAHL (1981 to July 2014), LILACS (1982 to July 2014) and Web of Science (1955 to July 2014). We also searched trials registries and contacted authors of trials requesting unpublished data.
SELECTION CRITERIA
We included randomised controlled trials comparing the effects of an oral monobacterial NTHi vaccine in adults with recurrent acute exacerbations of chronic bronchitis or COPD when there was overt matching of the vaccine and placebo groups on clinical grounds. The selection criteria considered populations aged less than 65 years and those older than 65 years.
DATA COLLECTION AND ANALYSIS
Two authors independently assessed trial quality and extracted data from original records and publications for incidence and severity of bronchitis episodes and carriage rate of NTHi measured in the upper respiratory tract, as well as data relevant to other primary and secondary outcomes.
MAIN RESULTS
We identified six placebo-controlled randomised controlled trials with a total of 557 participants. They investigated the efficacy of enteric-coated, killed preparations of H. influenzae in populations prone to recurrent acute exacerbations of chronic bronchitis or COPD. The vaccine preparation and immunisation regime in all trials consisted of at least three courses of formalin-killed H. influenzae in enteric-coated tablets taken at intervals (for example, days 0, 28 and 56). Each course generally consisted of two tablets taken after breakfast over three consecutive days. In all cases the placebo groups took enteric-coated tablets containing glucose. Risk of bias was moderate across the studies, namely due to the lack of information provided about methods and inadequate presentation of results.Meta-analysis of the oral NTHi vaccine showed a small, non-statistically significant reduction in the incidence of acute exacerbations of chronic bronchitis or COPD by 2.048% (risk ratio (RR) 0.97, 95% confidence interval (CI) 0.84 to 1.12, P value = 0.68). There was no significant difference in mortality rate between the vaccine and placebo groups (odds ratio (OR) 1.62, 95% CI 0.63 to 4.12, P value = 0.31).We were unable to meta-analyse the carriage levels of NTHi in participants as each trial reported this result using different units and tools of measurement. Four trials showed no significant difference in carriage levels, while two trials showed a significant decrease in carriage levels in the vaccinated group compared with placebo.Four trials assessed severity of exacerbations measured by requirement for antibiotics. Three of these trials were comparable and when meta-analysed showed a statistically significant 80% increase in antibiotic courses per person in the placebo group (RR 1.81, 95% CI 1.35 to 2.44, P value < 0.0001). There was no significant difference between the groups with regards to hospital admission rates (OR 0.96, 95% CI 0.13 to 7.04, P value = 0.97). Adverse events were reported in all six trials with a point estimate suggestive that they occurred more frequently in the vaccine group, however, this result was not statistically significant (RR 1.43, 95% CI 0.70 to 2.92, P value = 0.87). Quality of life was not meta-analysed but was reported in two trials, with results at six months showing an improvement in quality of life in the vaccinated group (scoring at least two points better than placebo).
AUTHORS' CONCLUSIONS
Analyses demonstrate that NTHi oral vaccination of patients with recurrent exacerbations of chronic bronchitis or COPD does not yield a significant reduction in the number and severity of exacerbations. Evidence is mixed and the individual trials that show a significant benefit of the vaccine are too small to advocate widespread oral vaccination of people with COPD.
Topics: Administration, Oral; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Bronchitis, Chronic; Disease Progression; Haemophilus Vaccines; Haemophilus influenzae; Humans; Middle Aged; Pulmonary Disease, Chronic Obstructive; Randomized Controlled Trials as Topic; Secondary Prevention
PubMed: 25201571
DOI: 10.1002/14651858.CD010010.pub2 -
American Journal of Orthopedics (Belle... May 2014Necrotizing fasciitis is a rare bacterial infection with an incidence of approximately 0.4 cases per 100,000 population. Although the majority of cases of necrotizing... (Review)
Review
Necrotizing fasciitis is a rare bacterial infection with an incidence of approximately 0.4 cases per 100,000 population. Although the majority of cases of necrotizing fasciitis are polymicrobial, a systematic review of the literature found only 7 reports of Haemophilus influenzae as the causal agent, and only 1 incidence of H influenzae causing the infection in a healthy adult. This report documents the unusual case of necrotizing fasciitis in a healthy adult with a history of smoking as her only risk factor. The patient presented with a seemingly innocuous low-grade Lisfranc injury. Our case illustrates the importance of early diagnosis and aggressive surgical management and medical treatment of necrotizing fasciitis.
Topics: Adult; Anti-Bacterial Agents; Debridement; Fasciitis, Necrotizing; Female; Foot Injuries; Haemophilus Infections; Haemophilus influenzae; Humans; Lower Extremity; Reoperation; Skin Transplantation
PubMed: 24839630
DOI: No ID Found -
PloS One 2014Community-acquired pneumonia (CAP) is one of the most important causes of morbidity and mortality worldwide. Etiological data for Cambodia is scarce. We aimed to... (Review)
Review
Etiologies and resistance profiles of bacterial community-acquired pneumonia in Cambodian and neighboring countries' health care settings: a systematic review (1995 to 2012).
OBJECTIVES
Community-acquired pneumonia (CAP) is one of the most important causes of morbidity and mortality worldwide. Etiological data for Cambodia is scarce. We aimed to describe the main etiological agents causing CAP, and their resistance patterns in Cambodia and the greater Mekong region.
METHODS
A review of bacterial etiologies of CAP and antimicrobial resistance in Cambodia and neighboring countries was conducted via: (1) a systematic review of published literature in all NCBI databases using Pubmed, Google scholar, EMBASE, the World Health Organization and the Cambodian Ministry of Health libraries; (2) a review of unpublished data from Cambodia provided by national and international stakeholders working at different tiers of the healthcare system.
RESULTS
Twenty three articles and five data sources reported etiologies for 5919 CAP patients diagnosed between May 1995 and December 2012, including 1421 (24.0%), 3571 (60.3%) and 927 (15.7%) from Cambodia, Thailand and Vietnam, respectively. Streptococcus pneumoniae and Haemophilus influenzae were the most common pathogens ranking among the five most prevalent in 12 and 10 studies, respectively. Gram-negative bacteria such as Burkholderia pseudomallei and Klebsiella pneumoniae were also frequently diagnosed, particularly in bacteremic CAP in Thai adults and Cambodian children. In Thailand and Vietnam, Mycoplasma pneumoniae and Chlamydia pneumoniae were frequently identified in settings using indirect laboratory testing.
CONCLUSIONS
Based on this analysis, CAP data in Cambodia seems to present etiological and resistance profiles comparable to those of neighboring countries. Findings have been shared with the national authorities upon the revision of the national therapeutic guidelines and were disseminated using a specially created website.
Topics: Burkholderia pseudomallei; Cambodia; Chlamydophila pneumoniae; Community-Acquired Infections; Drug Resistance, Bacterial; Haemophilus influenzae; Humans; Klebsiella pneumoniae; Mycoplasma pneumoniae; Pneumonia, Bacterial; Prevalence; Streptococcus pneumoniae
PubMed: 24626053
DOI: 10.1371/journal.pone.0089637 -
BMC Public Health 2013Two of the most prevalent causes of severe bacterial meningitis in children, Haemophilus influenzae type B (Hib) and Streptococcus pneumoniae, are preventable by... (Review)
Review
BACKGROUND
Two of the most prevalent causes of severe bacterial meningitis in children, Haemophilus influenzae type B (Hib) and Streptococcus pneumoniae, are preventable by existing vaccines increasingly available in developing countries. Our objective was to estimate the dose-specific effect of Hib and pneumococcal conjugate vaccines (PCV) on childhood meningitis mortality in low-income countries for use in the Lives Saved Tool (LiST).
METHODS
We systematically searched and reviewed published vaccine efficacy trials and observational studies reporting the effect of Hib or PCV vaccines on organism-specific meningitis, bacterial meningitis and all-cause meningitis incidence and mortality among children less than five years old in low- and middle-income countries. Data collection and quality assessments were performed using standardized guidelines. For outcomes available across multiple studies (≥ 2) and approximating meningitis mortality, we pooled estimates reporting dose-specific effects using random effects meta-analytic methods, then combined these with meningitis etiology data to determine the preventable fraction of childhood meningitis mortality for inclusion in LiST.
RESULTS
We identified 18 studies of Hib conjugate vaccines reporting relevant meningitis morbidity and mortality outcomes (2 randomized controlled trials [RCTs], 16 observational studies) but few provided dose-specific effects. A meta-analysis of four case-control studies examined the dose-specific effect of Hib conjugate vaccines on Hib meningitis morbidity (1 dose: RR=0.64, 95% CI 0.38-1.06; 2 doses: RR=0.09, 95% CI 0.03-0.27; 3 doses: RR=0.06, 95% CI 0.02-0.22), consistent with results from single RCTs. Pooled estimates of two RCTs provided evidence for the effect of three doses of PCV on vaccine-serotype meningitis morbidity (RR=0.16, 95% CI 0.02-1.20). We considered these outcomes of severe disease as proxy estimates for meningitis mortality and combined the estimates of protective effects with meningitis etiology data to provide an estimate of the preventable fraction of childhood meningitis mortality with three doses of Hib (38-43%) and pneumococcal conjugate vaccines (28-35%) for use in LiST.
CONCLUSIONS
Few RCTs or vaccine effectiveness studies evaluated the dose-specific impact of Hib and PCV vaccines on childhood meningitis mortality, necessitating use of proxy measures to estimate population impact in LiST. Our analysis indicates that approximately three-quarters of meningitis deaths are preventable with existing Hib and PCV vaccines.
Topics: Bacterial Capsules; Child; Child Welfare; Child, Preschool; Developing Countries; Haemophilus Vaccines; Haemophilus influenzae type b; Humans; Incidence; Meningitis, Bacterial; Meningitis, Haemophilus; Pneumococcal Vaccines; Vaccines, Conjugate
PubMed: 24564188
DOI: 10.1186/1471-2458-13-S3-S21 -
The Pediatric Infectious Disease Journal Nov 2013The optimal schedule and the need for a booster dose are unclear for Haemophilus influenzae type b (Hib) conjugate vaccines. We systematically reviewed relative effects... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The optimal schedule and the need for a booster dose are unclear for Haemophilus influenzae type b (Hib) conjugate vaccines. We systematically reviewed relative effects of Hib vaccine schedules.
METHODS
We searched 21 databases to May 2010 or June 2012 and selected randomized controlled trials or quasi-randomized controlled trials that compared different Hib schedules (3 primary doses with no booster dose [3p+0], 3p+1 and 2p+1) or different intervals in primary schedules and between primary and booster schedules. Outcomes were clinical efficacy, nasopharyngeal carriage and immunological response. Results were combined in random-effects meta-analysis.
RESULTS
Twenty trials from 15 countries were included; 16 used vaccines conjugated to tetanus toxoid (polyribosylribitol phosphate conjugated to tetanus toxoid). No trials assessed clinical or carriage outcomes. Twenty trials examined immunological outcomes and found few relevant differences. Comparing polyribosylribitol phosphate conjugated to tetanus toxoid 3p+0 with 2p+0, there was no difference in seropositivity at the 1.0 μg/mL threshold by 6 months after the last primary dose (combined risk difference -0.02; 95% confidence interval: -0.10, 0.06). Only small differences were seen between schedules starting at different ages, with different intervals between primary doses, or with different intervals between primary and booster doses. Individuals receiving a booster were more likely to be seropositive than those at the same age who did not.
CONCLUSIONS
There is no clear evidence from trials that any 2p+1, 3p+0 or 3p+1 schedule of Hib conjugate vaccine is likely to provide better protection against Hib disease than other schedules. Until more data become available, scheduling is likely to be determined by epidemiological and programmatic considerations in individual settings.
Topics: Haemophilus Infections; Haemophilus Vaccines; Haemophilus influenzae type b; Humans; Immunization Schedule; Infant; Infant, Newborn; Randomized Controlled Trials as Topic; Vaccines, Conjugate
PubMed: 24145955
DOI: 10.1097/INF.0b013e31829f0a7e