Childhood vaccinations and risk of asthma

Association Between Aluminum Exposure From Vaccines Before Age 24 Months and Persistent Asthma at Age 24 to 59 Months

OBJECTIVE

To assess the association between cumulative aluminum exposure from vaccines before age 24 months and persistent asthma at age 24 to 59 months.

METHODS

A retrospective cohort study was conducted in the Vaccine Safety Datalink (VSD). Vaccination histories were used to calculate cumulative vaccine-associated aluminum in milligrams (mg). The persistent asthma definition required one inpatient or 2 outpatient asthma encounters, and ≥2 long-term asthma control medication dispenses. Cox proportional hazard models were used to evaluate the association between aluminum exposure and asthma incidence, stratified by eczema presence/absence. Adjusted hazard ratios (aHR) and 95% confidence intervals (CI) per 1 mg increase in aluminum exposure were calculated, adjusted for birth month/year, sex, race/ethnicity, VSD site, prematurity, medical complexity, food allergy, severe bronchiolitis, and health care utilization.

RESULTS

The cohort comprised 326,991 children, among whom 14,337 (4.4%) had eczema. For children with and without eczema, the mean (standard deviation [SD]) vaccine-associated aluminum exposure was 4.07 mg (SD 0.60) and 3.98 mg (SD 0.72), respectively. Among children with and without eczema, 6.0% and 2.1%, respectively, developed persistent asthma. Among children with eczema, vaccine-associated aluminum was positively associated with persistent asthma (aHR 1.26 per 1 mg increase in aluminum, 95% CI 1.07, 1.49); a positive association was also detected among children without eczema (aHR 1.19, 95% CI 1.14, 1.25).

CONCLUSION

In a large observational study, a positive association was found between vaccine-related aluminum exposure and persistent asthma. While recognizing the small effect sizes identified and the potential for residual confounding, additional investigation of this hypothesis appears warranted.

Challenges in the Pharmacotherapeutic Management of Pediatric Asthma

Bronchial asthma is one of the most common chronic conditions in pediatric practice, with increasing prevalence hampered by poor socioeconomic impacts, leading to major public health issues. Considered as a complex heterogeneous syndrome, not a single disease, the management of the disease is a real challenge, impacting medical staff, patients and caregivers. Over the decades, a significant number of diagnostic and treatment regimen have been developed to achieve good standards, sustaining balanced control of the disease. This paper attempts a review on the establishment of new trends in the management of bronchial asthma in the pediatric age group.

Vaccines for measles, mumps, rubella, and varicella in children

BACKGROUND

Measles, mumps, rubella, and varicella (chickenpox) are serious diseases that can lead to serious complications, disability, and death. However, public debate over the safety of the trivalent MMR vaccine and the resultant drop in vaccination coverage in several countries persists, despite its almost universal use and accepted effectiveness. This is an update of a review published in 2005 and updated in 2012.

OBJECTIVES

To assess the effectiveness, safety, and long- and short-term adverse effects associated with the trivalent vaccine, containing measles, rubella, mumps strains (MMR), or concurrent administration of MMR vaccine and varicella vaccine (MMR+V), or tetravalent vaccine containing measles, rubella, mumps, and varicella strains (MMRV), given to children aged up to 15 years.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2019, Issue 5), which includes the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE (1966 to 2 May 2019), Embase (1974 to 2 May 2019), the WHO International Clinical Trials Registry Platform (2 May 2019), and ClinicalTrials.gov (2 May 2019).

SELECTION CRITERIA

We included randomised controlled trials (RCTs), controlled clinical trials (CCTs), prospective and retrospective cohort studies (PCS/RCS), case-control studies (CCS), interrupted time-series (ITS) studies, case cross-over (CCO) studies, case-only ecological method (COEM) studies, self-controlled case series (SCCS) studies, person-time cohort (PTC) studies, and case-coverage design/screening methods (CCD/SM) studies, assessing any combined MMR or MMRV / MMR+V vaccine given in any dose, preparation or time schedule compared with no intervention or placebo, on healthy children up to 15 years of age.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the methodological quality of the included studies. We grouped studies for quantitative analysis according to study design, vaccine type (MMR, MMRV, MMR+V), virus strain, and study settings. Outcomes of interest were cases of measles, mumps, rubella, and varicella, and harms. Certainty of evidence of was rated using GRADE.

MAIN RESULTS

We included 138 studies (23,480,668 participants). Fifty-one studies (10,248,159 children) assessed vaccine effectiveness and 87 studies (13,232,509 children) assessed the association between vaccines and a variety of harms. We included 74 new studies to this 2019 version of the review. Effectiveness Vaccine effectiveness in preventing measles was 95% after one dose (relative risk (RR) 0.05, 95% CI 0.02 to 0.13; 7 cohort studies; 12,039 children; moderate certainty evidence) and 96% after two doses (RR 0.04, 95% CI 0.01 to 0.28; 5 cohort studies; 21,604 children; moderate certainty evidence). The effectiveness in preventing cases among household contacts or preventing transmission to others the children were in contact with after one dose was 81% (RR 0.19, 95% CI 0.04 to 0.89; 3 cohort studies; 151 children; low certainty evidence), after two doses 85% (RR 0.15, 95% CI 0.03 to 0.75; 3 cohort studies; 378 children; low certainty evidence), and after three doses was 96% (RR 0.04, 95% CI 0.01 to 0.23; 2 cohort studies; 151 children; low certainty evidence). The effectiveness (at least one dose) in preventing measles after exposure (post-exposure prophylaxis) was 74% (RR 0.26, 95% CI 0.14 to 0.50; 2 cohort studies; 283 children; low certainty evidence). The effectiveness of Jeryl Lynn containing MMR vaccine in preventing mumps was 72% after one dose (RR 0.24, 95% CI 0.08 to 0.76; 6 cohort studies; 9915 children; moderate certainty evidence), 86% after two doses (RR 0.12, 95% CI 0.04 to 0.35; 5 cohort studies; 7792 children; moderate certainty evidence). Effectiveness in preventing cases among household contacts was 74% (RR 0.26, 95% CI 0.13 to 0.49; 3 cohort studies; 1036 children; moderate certainty evidence).  Vaccine effectiveness against rubella, using a vaccine with the BRD2 strain which is only used in China, is 89% (RR 0.11, 95% CI 0.03 to 0.42; 1 cohort study; 1621 children; moderate certainty evidence).  Vaccine effectiveness against varicella (any severity) after two doses in children aged 11 to 22 months is 95% in a 10 years follow-up (rate ratio (rr) 0.05, 95% CI 0.03 to 0.08; 1 RCT; 2279 children; high certainty evidence). Safety There is evidence supporting an association between aseptic meningitis and MMR vaccines containing Urabe and Leningrad-Zagreb mumps strains, but no evidence supporting this association for MMR vaccines containing Jeryl Lynn mumps strains (rr 1.30, 95% CI 0.66 to 2.56; low certainty evidence). The analyses provide evidence supporting an association between MMR/MMR+V/MMRV vaccines (Jeryl Lynn strain) and febrile seizures. Febrile seizures normally occur in 2% to 4% of healthy children at least once before the age of 5. The attributable risk febrile seizures vaccine-induced is estimated to be from 1 per 1700 to 1 per 1150 administered doses. The analyses provide evidence supporting an association between MMR vaccination and idiopathic thrombocytopaenic purpura (ITP). However, the risk of ITP after vaccination is smaller than after natural infection with these viruses. Natural infection of ITP occur in 5 cases per 100,000 (1 case per 20,000) per year. The attributable risk is estimated about 1 case of ITP per 40,000 administered MMR doses. There is no evidence of an association between MMR immunisation and encephalitis or encephalopathy (rate ratio 0.90, 95% CI 0.50 to 1.61; 2 observational studies; 1,071,088 children; low certainty evidence), and autistic spectrum disorders (rate ratio 0.93, 95% CI 0.85 to 1.01; 2 observational studies; 1,194,764 children; moderate certainty). There is insufficient evidence to determine the association between MMR immunisation and inflammatory bowel disease (odds ratio 1.42, 95% CI 0.93 to 2.16; 3 observational studies; 409 cases and 1416 controls; moderate certainty evidence). Additionally, there is no evidence supporting an association between MMR immunisation and cognitive delay, type 1 diabetes, asthma, dermatitis/eczema, hay fever, leukaemia, multiple sclerosis, gait disturbance, and bacterial or viral infections.  AUTHORS' CONCLUSIONS: Existing evidence on the safety and effectiveness of MMR/MMRV vaccines support their use for mass immunisation. Campaigns aimed at global eradication should assess epidemiological and socioeconomic situations of the countries as well as the capacity to achieve high vaccination coverage. More evidence is needed to assess whether the protective effect of MMR/MMRV could wane with time since immunisation.

Vaccine Hesitancy: Drivers and How the Allergy Community Can Help

Vaccine hesitancy-defined by the World Health Organization (WHO) as a "delay in acceptance or refusal of vaccines despite availability of vaccination services"-is not a recent phenomenon. Historical records indicate that vaccine hesitancy existed by the 18th century in Europe and even resulted in violent riots. The drivers of vaccine hesitancy have evolved over the last 200 years but not, perhaps, as much as one might expect. More problematic are the means by which concerns over vaccine hesitancy are communicated by a new landscape of digital communication, generating what has been described as an "infodemic" in which an overabundance of information-both factual and misinformation-contributes to hesitancy. In this review, we discuss the background and current drivers of vaccine hesitancy and the evidence base for strategies to combat this. We highlight the important role the allergy/immunology community could have in working to mitigate vaccine hesitancy, particularly with respect to the current coronavirus disease 2019 (COVID-19) pandemic.

Childhood vaccination and allergy: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

As the rise in prevalence of allergic diseases worldwide corresponds in time with increasing infant vaccination, it has been hypothesized that childhood vaccination may increase the risk of allergic disease. We aimed to synthesize the literature on the association between childhood vaccination and allergy.

DESIGN

We searched the electronic databases PubMed and EMBASE (January 1946-January 2018) using vaccination and allergy terms.

METHODS

Two authors selected papers according to the inclusion criteria. Pooled effects across studies were estimated using random-effects meta-analysis. Due to inadequate number of homogeneous publications on newer and underused vaccines, meta-analysis was limited to allergic outcomes following administration of (Bacillus Calmette-Guérin) BCG, measles or pertussis vaccination. The review was prospectively registered in the PROSPERO systematic review registry (NO: CRD42017071009).

RESULTS

A total of 35 publications based on cohort studies and 7 publications based on randomized controlled trials (RCTs) met the inclusion criteria. RCTs: From 2 studies, early vaccination with BCG vaccine was associated with a reduced risk of eczema (RR = 0.83; 95% CI = 0.73-0.93; I²  = 0%) but not food allergy or asthma. No association was found between pertussis vaccine and any allergic outcome based on a single RCT.

COHORT STUDIES

Childhood measles vaccination was associated with a reduced risk of eczema (RR = 0.65; 95% CI = 0.47-0.90, I²  = 0.0%), asthma (RR = 0.78; 95% CI = 0.62-0.98, I²  = 93.9%) and, with a similar, statistically non-significant reduction in sensitization (RR = 0.78; 95% CI = 0.61-1.01, I²  = 19.4%).

CONCLUSIONS

We found no evidence that childhood vaccination with commonly administered vaccines was associated with increased risk of later allergic disease. Our results from pooled analysis of both RCTs and cohort studies suggest that vaccination with BCG and measles vaccines were associated with a reduced risk of eczema.

Fact vs Fallacy: The Anti-Vaccine Discussion Reloaded

In the light of the COVID-19 pandemic, anti-vaccine sentiments have been on the rise, with a recent seminal study on the development of anti-vaccine views in social media even making its way into Nature Communications. Yet, with the current scientific consensus being in overwhelming agreement over the safety and efficacy of vaccines, many scientists lose their grasp on the fears, concerns, and arguments that the opposition may hold. This paper discusses and evaluates vaccine-hesitant individuals on a socioeconomic, historical, and philosophical landscape. It also provides an analysis of common argumentative patterns and the psychological impact that these arguments may have on undecided individuals. The discussion also explores why anti-vaccine sentiments are on the rise, and how members of the scientific and medical community require a more structured approach to communicating key arguments. This is particularly important if vaccination rates and herd immunity are to be sustained. No longer is it sufficient to win arguments based on a factual and scientific basis, but rather scientists and medical practitioners have to focus on conveying confidence and reassurance on both an informative and emotional level to those with doubts and fears.

Measles, mumps and rubella vs diphtheria-tetanus-acellular-pertussis-inactivated-polio-Haemophilus influenzae type b as the most recent vaccine and risk of early 'childhood asthma'

BACKGROUND AND OBJECTIVE

Live vaccines may have beneficial non-specific effects. We tested whether the live measles, mumps and rubella (MMR) vaccine compared with the non-live diphtheria-tetanus-acellular-pertussis-inactivated-polio-Haemophilus influenzae type b (DTaP-IPV-Hib) vaccine as the most recent vaccine was associated with less childhood asthma and fewer acute hospital contacts for childhood asthma among boys and girls.

METHODS

This study is a nationwide register-based cohort study of 338 761 Danish children born between 1999 and 2006. We compared (i) the incidence of first-registered childhood asthma based on hospital contacts and drug prescriptions and (ii) the incidence of severe asthma defined as acute hospital contacts for childhood asthma between the ages of 15 and 48 months among children whose last received vaccine was three doses of DTaP-IPV-Hib and then MMR with children whose last received vaccine was three doses of DTaP-IPV-Hib.

RESULTS

For boys, following the recommended vaccine schedule of MMR after DTaP-IPV-Hib3 compared with DTaP-IPV-Hib3 as the last received vaccine, MMR was associated with 8.1 (95% confidence interval 3.9-12.3) fewer childhood asthma cases per 1000 boys, corresponding to 10% (5-15%) reduction in the cumulative incidence of childhood asthma. MMR, when given last, was also associated with 16.3 (95% confidence interval 12.7-20.0) fewer acute hospital admissions for childhood asthma per 1000 boys, corresponding to a 27% (22-31%) reduction in the cumulative incidence. No associations were seen for girls.

CONCLUSION

MMR may have a protective effect against childhood asthma for boys. This calls for an understanding of whether non-specific effects of vaccines can be used to optimize our vaccine programmes.

Vaccines for measles, mumps, rubella, and varicella in children

BACKGROUND

Measles, mumps, rubella, and varicella (chickenpox) are serious diseases that can lead to serious complications, disability, and death. However, public debate over the safety of the trivalent MMR vaccine and the resultant drop in vaccination coverage in several countries persists, despite its almost universal use and accepted effectiveness. This is an update of a review published in 2005 and updated in 2012.

OBJECTIVES

To assess the effectiveness, safety, and long- and short-term adverse effects associated with the trivalent vaccine, containing measles, rubella, mumps strains (MMR), or concurrent administration of MMR vaccine and varicella vaccine (MMR+V), or tetravalent vaccine containing measles, rubella, mumps, and varicella strains (MMRV), given to children aged up to 15 years.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2019, Issue 5), which includes the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE (1966 to 2 May 2019), Embase (1974 to 2 May 2019), the WHO International Clinical Trials Registry Platform (2 May 2019), and ClinicalTrials.gov (2 May 2019).

SELECTION CRITERIA

We included randomised controlled trials (RCTs), controlled clinical trials (CCTs), prospective and retrospective cohort studies (PCS/RCS), case-control studies (CCS), interrupted time-series (ITS) studies, case cross-over (CCO) studies, case-only ecological method (COEM) studies, self-controlled case series (SCCS) studies, person-time cohort (PTC) studies, and case-coverage design/screening methods (CCD/SM) studies, assessing any combined MMR or MMRV / MMR+V vaccine given in any dose, preparation or time schedule compared with no intervention or placebo, on healthy children up to 15 years of age.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the methodological quality of the included studies. We grouped studies for quantitative analysis according to study design, vaccine type (MMR, MMRV, MMR+V), virus strain, and study settings. Outcomes of interest were cases of measles, mumps, rubella, and varicella, and harms. Certainty of evidence of was rated using GRADE.

MAIN RESULTS

We included 138 studies (23,480,668 participants). Fifty-one studies (10,248,159 children) assessed vaccine effectiveness and 87 studies (13,232,509 children) assessed the association between vaccines and a variety of harms. We included 74 new studies to this 2019 version of the review. Effectiveness Vaccine effectiveness in preventing measles was 95% after one dose (relative risk (RR) 0.05, 95% CI 0.02 to 0.13; 7 cohort studies; 12,039 children; moderate certainty evidence) and 96% after two doses (RR 0.04, 95% CI 0.01 to 0.28; 5 cohort studies; 21,604 children; moderate certainty evidence). The effectiveness in preventing cases among household contacts or preventing transmission to others the children were in contact with after one dose was 81% (RR 0.19, 95% CI 0.04 to 0.89; 3 cohort studies; 151 children; low certainty evidence), after two doses 85% (RR 0.15, 95% CI 0.03 to 0.75; 3 cohort studies; 378 children; low certainty evidence), and after three doses was 96% (RR 0.04, 95% CI 0.01 to 0.23; 2 cohort studies; 151 children; low certainty evidence). The effectiveness (at least one dose) in preventing measles after exposure (post-exposure prophylaxis) was 74% (RR 0.26, 95% CI 0.14 to 0.50; 2 cohort studies; 283 children; low certainty evidence). The effectiveness of Jeryl Lynn containing MMR vaccine in preventing mumps was 72% after one dose (RR 0.24, 95% CI 0.08 to 0.76; 6 cohort studies; 9915 children; moderate certainty evidence), 86% after two doses (RR 0.12, 95% CI 0.04 to 0.35; 5 cohort studies; 7792 children; moderate certainty evidence). Effectiveness in preventing cases among household contacts was 74% (RR 0.26, 95% CI 0.13 to 0.49; 3 cohort studies; 1036 children; moderate certainty evidence). Vaccine effectiveness against rubella is 89% (RR 0.11, 95% CI 0.03 to 0.42; 1 cohort study; 1621 children; moderate certainty evidence). Vaccine effectiveness against varicella (any severity) after two doses in children aged 11 to 22 months is 95% in a 10 years follow-up (rate ratio (rr) 0.05, 95% CI 0.03 to 0.08; 1 RCT; 2279 children; high certainty evidence). Safety There is evidence supporting an association between aseptic meningitis and MMR vaccines containing Urabe and Leningrad-Zagreb mumps strains, but no evidence supporting this association for MMR vaccines containing Jeryl Lynn mumps strains (rr 1.30, 95% CI 0.66 to 2.56; low certainty evidence). The analyses provide evidence supporting an association between MMR/MMR+V/MMRV vaccines (Jeryl Lynn strain) and febrile seizures. Febrile seizures normally occur in 2% to 4% of healthy children at least once before the age of 5. The attributable risk febrile seizures vaccine-induced is estimated to be from 1 per 1700 to 1 per 1150 administered doses. The analyses provide evidence supporting an association between MMR vaccination and idiopathic thrombocytopaenic purpura (ITP). However, the risk of ITP after vaccination is smaller than after natural infection with these viruses. Natural infection of ITP occur in 5 cases per 100,000 (1 case per 20,000) per year. The attributable risk is estimated about 1 case of ITP per 40,000 administered MMR doses. There is no evidence of an association between MMR immunisation and encephalitis or encephalopathy (rate ratio 0.90, 95% CI 0.50 to 1.61; 2 observational studies; 1,071,088 children; low certainty evidence), and autistic spectrum disorders (rate ratio 0.93, 95% CI 0.85 to 1.01; 2 observational studies; 1,194,764 children; moderate certainty). There is insufficient evidence to determine the association between MMR immunisation and inflammatory bowel disease (odds ratio 1.42, 95% CI 0.93 to 2.16; 3 observational studies; 409 cases and 1416 controls; moderate certainty evidence). Additionally, there is no evidence supporting an association between MMR immunisation and cognitive delay, type 1 diabetes, asthma, dermatitis/eczema, hay fever, leukaemia, multiple sclerosis, gait disturbance, and bacterial or viral infections.

AUTHORS' CONCLUSIONS

Existing evidence on the safety and effectiveness of MMR/MMRV vaccines support their use for mass immunisation. Campaigns aimed at global eradication should assess epidemiological and socioeconomic situations of the countries as well as the capacity to achieve high vaccination coverage. More evidence is needed to assess whether the protective effect of MMR/MMRV could wane with time since immunisation.

Incidence rates of health outcomes of interest among Chinese children exposed to selected vaccines in Yinzhou Electronic Health Records: A population-based retrospective cohort study

INTRODUCTION

Oral poliovirus vaccine (OPV) and diphtheria-tetanus-acellular pertussis vaccine (DTaP) are widely used in China while Haemophilus influenzae type b vaccines (Hib) and a DTaP, inactivated poliovirus (IPV) andHib polysaccharide conjugated to tetanus protein (PRP ~ T) combined vaccine (DTaP-IPV//PRP ~ T) have lower coverage. There are limited safety data on these vaccines in Chinese pediatric populations.

METHODS

To estimate incidence rates (IRs) of health outcomes of interest (HOIs) among children exposed to OPV, DTaP, Hib, and DTaP-IPV//PRP ~ T, we conducted a retrospective cohort study using a population-based electronic health record (EHR) database in Yinzhou district, Ningbo City. Children 0-2 years of age receiving at least one dose of these vaccines between January 1, 2012 and March 31, 2017 were included in the study. Yinzhou EHR database consisted of immunization records and healthcare data of children from hospitals and community health centers in the district. Eight HOIs (i.e., anaphylaxis, febrile seizures, all seizures, asthma, apnea, Kawasaki disease [KD], urticaria/angioedema, Guillain-Barré syndrome [GBS]) were identified using ICD-10 codes.

RESULTS

A total of 220,422 eligible children was identified. No cases of apnea, KD, and GBS were observed within 7 days post-vaccination. During 0-7 days post-vaccination for OPV, DTaP, Hib, and DTaP-IPV//PRP ~ T, the IRs of anaphylaxis, febrile seizures, all seizures, urticaria/angioedema and asthma ranged from 0.0 to 50.0, 0.0 to 99.9, 29.1 to 249.8, 297.8 to 949.1, and 992.7 to 2298.2 per 100,000 person-years, respectively, and 0.0 to 0.9, 0.0 to 1.9, 0.6 to 4.6, 5.6 to 17.5, and 18.7 to 42.3 per 100,000 doses, respectively.

CONCLUSION

IRs of some HOIs in our study were comparable with those in the literature while IRs of other HOIs were not due to differences in study design, post-vaccination risk periods assessed, and vaccine types. Future studies should consider medical chart review for validating HOIs obtained in the EHR.

Challenges in evaluating post-licensure vaccine safety: observations from the Centers for Disease Control and Prevention

Introduction: Vaccination is one of the most successful and cost-effective public health interventions. Although vaccines undergo extensive safety and efficacy evaluations prior to licensure, vaccine safety assessment post-licensure is essential for detecting rare and longer-term adverse events (AEs) and maintaining public confidence in vaccines and recommended immunization programs. Despite the proven effect of vaccines to save lives and prevent disease and overwhelming evidence of vaccines' safety and societal benefit, like any drug, no vaccine can be considered as completely safe and completely effective. New vaccines continue to be introduced and require rapid safety assessment post-licensure through pharmacovigilance reports as well as epidemiologic studies to investigate any potential safety signals.Areas covered: We discuss selected challenges for conducting pharmacovigilance and epidemiologic studies of AEs after vaccination in the United States using the post-licensure safety surveillance infrastructure of the Centers for Disease Control and Prevention (CDC).Expert opinion: The availability of specific post-licensure surveillance systems to monitor and study AEs after vaccination, such as the Vaccine Adverse Event Reporting System, the Vaccine Safety Datalink, and the Clinical Immunization Safety Assessment Project, each with its unique set of strengths and limitations, provide a harmonized and supportive approach to meet several of these barriers.

A cross-sectional study of the relationship between reported human papillomavirus vaccine exposure and the incidence of reported asthma in the United States

Objectives:

Asthma is a chronic disorder that affects persons of all ages impacting the quality of their lives. This cross-sectional hypothesis-testing study evaluated the relationship between human papillomavirus vaccine and the risk of an incident asthma diagnosis in a defined temporal period post-vaccination.

Methods:

The 2015–2016 National Health and Nutrition Examination Survey data were examined for a group of 60,934,237 weighted persons between 9 and 26 years old in Statistical Analysis Software.

Results:

Reported incident asthma significantly clustered in the year of reported human papillomavirus vaccination. When the data were separated by gender, the effects observed remained significant for males but not females.

Conclusion:

The results suggest that human papillomavirus vaccination resulted in an excess of 261,475 asthma cases with an estimated direct excess lifetime cost of such persons being US$42 billion. However, it is unclear what part of the vaccine and/or vaccine medium may have increased an individual’s susceptibility to an asthma episode, whether the asthma diagnosis represented one asthma episode or if it is chronic, and how much therapeutic support was needed (if any) and for how long, which would impact cost. Despite the negative findings in this study, routine vaccination is an important public health tool, and the results observed need to be viewed in this context.

Vaccination and Allergic Sensitization in Early Childhood - The ALADDIN Birth Cohort

BACKGROUND

The increasing incidence of allergic diseases highlights the importance of finding underlying mechanisms. Early vaccination has been suggested as one influential factor. However, it is difficult to find a study group with a large variation between subjects concerning compliance to the official vaccination program. The anthroposophic lifestyle is of interest in this context. Moreover, cohort studies show that children of families with this lifestyle run a lower risk of allergic sensitization and allergy-related disease.

METHODS

From the prospective birth cohort ALADDIN we included one group from the anthroposophic community, with restrictive attitudes concerning vaccinations, and two other groups of age-matched children with more conventional parental lifestyles. In all, 466 children were followed from birth to five years of age. Detailed vaccination data and blood samples were collected at six months, one, two, and five years. Information was also obtained on risk factors for allergy. The outcome variable, allergic sensitization was defined as allergen-specific serum IgE levels ≥ 0.35 kU_A/L.

FINDINGS

In a logistic regression model adjusted for socio-demographics and established allergy risk factors, vaccination at later age or having a lower number of injections or vaccines were associated with low OR for allergic sensitization during the first year of life. However, after adjustment for anthroposophic lifestyle, no statistically significant associations remained. The adjusted OR for sensitization at five years of age in children not receiving any vaccinations (n = 54) was 0.98 [95% CI 0.38-2.57].

INTERPRETATION

We found no support for an association between early childhood vaccination and subsequent allergic sensitization. Our findings do not support scepticism towards early childhood vaccination motivated by allergy risk.

Immunological considerations regarding parental concerns on pediatric immunizations

Despite the fundamental role of vaccines in the decline of infant mortality, parents may decide to decline vaccination for their own children. Many factors may influence this decision, such as the belief that the infant immune system is weakened by vaccines, and concerns have been raised about the number of vaccines and the early age at which they are administered. Studies focused on the infant immune system and its reaction to immunizations, summarized in this review, show that vaccines can overcome those suboptimal features of infant immune system that render them more at risk of infections and of their severe manifestations. In addition, many vaccines have been shown to improve heterologous innate and adaptive immunity resulting in lower mortality rates for fully vaccinated children. Thus, multiple vaccinations are necessary and not dangerous, as infants can respond to several antigens as well as when responding to single stimuli. Current immunization schedules have been developed and tested to avoid vaccine interference, improve benefits and reduce side effects compared to single administrations. The infant immune system is therefore capable, early after birth, of managing several antigenic challenges and exploits them to prompt its development.

Programmed vaccination may increase the prevalence of asthma and allergic diseases

BACKGROUND

The prevalence of asthma and allergic diseases has risen in recent decades. The etiology of asthma and allergic diseases has not been entirely elucidated.

OBJECTIVE

In this study, we investigated the possibility that programmed vaccination in China may have a potential role in asthma and allergic diseases.

METHODS

In this animal model, newborn BALB/c mice were randomly divided into three groups: vaccine plus ovalbumin (OVA), OVA, and control. The mice of vaccine plus OVA only group were inoculated with vaccines by following the National Vaccines Inoculation Program in China. Mice of vaccine plus OVA and OVA only groups were sensitized and challenged with OVA. Airway hyperresponsiveness was assessed by lung function and serum interleukin (IL) 4 and interferon (IFN) γ were measured.

RESULTS

The results of lung function showed that mice of the vaccine plus OVA group exhibited an increase in enhanced pause (Penh) compared with that in the OVA group at methacholine concentrations of 6.25 and 12.5 mg/mL (p < 0.05). Serum IL-4 in the vaccine plus OVA group was higher than that in the OVA group (p < 0.01). The serum IFN-γ level in the OVA group was lower than that in the control group (p < 0.01), and also lower than that in the vaccine plus OVA group (p < 0.05). The ratio of IFN-γ to IL-4 both in the OVA and vaccine plus OVA group was lower than that in the control group (p < 0.01).

CONCLUSIONS

Results of our study indicated that programmed vaccination in China may have a potential role in the prevalence of asthma and allergic diseases by inducing T-helper 2 cytokine expression and may be responsible for the increasing prevalence of asthma and allergic diseases in China.

Immunomodulation of TH2 biased immunity with mucosal administration of nanoemulsion adjuvant

TH2-biased immune responses are associated with inadequate protection against some pathogens and with cancer, colitis, asthma and allergy. Since most currently used vaccine adjuvants induce a TH2-biased response, this has led to interest in developing adjuvants capable of activating TH1 immunity and modulating existing TH2 responses. Immunotherapies to shift immune responses from TH2 to TH1 have generally required prolonged immunization protocols and have not induced effective TH1 responses. We have demonstrated that nanoscale emulsions (NE), a novel mucosal adjuvant, induce robust IgA and IgG antibody responses and TH1/TH17 cellular immunity resulting in protection against a variety of respiratory and mucosal infections. Because intranasal (i.n.) delivery of NE adjuvant consistently induces TH1/TH17 biased responses, we hypothesized that NE could be used as a therapeutic vaccine to redirect existing TH2 polarized immunity towards a more balanced TH1/TH2 profile. To test this, a TH2 immune response was established by intramuscular immunization of mice with alum-adjuvanted hepatitis B surface antigen (HBs), followed by a single subsequent i.n. immunization with NE-HBs. These animals exhibited increased TH1 associated immune responses and IL-17, and decreased TH2 cytokines (IL-4 and IL-5) and IgG1. NE immunization induced regulatory T cells and IL-10, and IL-10 was required for the suppression of TH2 immunity. These data demonstrate that NE-based vaccines can modulate existing TH2 immune responses to promote TH1/TH17 immunity and suggest the potential therapeutic use of NE vaccines for diseases associated with TH2 immunity.

Asthma and allergy in children with and without prior measles, mumps, and rubella vaccination

BACKGROUND

The existing literature on the association between measles vaccination and subsequent risk of allergic disease is inconclusive. The aim of this study was, therefore, to determine whether measles, mumps, and rubella (MMR) vaccination administered in early childhood was associated with asthma and allergic diseases at ages 5, 7 and 13 yrs in a birth cohort.

METHODS

In the Faroe Islands, 640 children were followed from birth. Follow-up examinations at ages 5, 7 and 13 yrs included a physical examination and a maternal questionnaire about the child's health. At age 7, total and grass-specific IgE was quantified in the child's serum, and at age 13, the children underwent skin prick tests (SPT). The child's vaccination card was reviewed at examinations.

RESULTS

At age 5, 533 of 555 children had been vaccinated for MMR. After confounder adjustment, we found early life MMR vaccination to be associated with a two-third reduction in the odds of asthma (OR: 0.33, 95% CI: 0.12; 0.90) and hypersensitivity/allergy (OR: 0.32, 95% CI: 0.11; 0.88) at age 5, and the substantially decreased odds of asthma were replicated at age 13 (OR: 0.22, 95% CI: 0.08; 0.56). At age 7, serum total IgE was reduced by 62.8% (CI 95%: -84.3%; -11.9%) in the vaccinated children. MMR vaccination was not significantly associated with allergic rhinoconjuctivitis symptoms, eczema, or SPT reactions at age 13.

CONCLUSIONS

MMR vaccination early in life may have a protective effect against allergy at least up to age 7 and against asthma through age 13 yrs.

The Vaccine Safety Datalink: successes and challenges monitoring vaccine safety

The Vaccine Safety Datalink (VSD) is a collaborative project between the Centers for Disease Control and Prevention (CDC) and 9 health care organizations. Established in 1990, VSD is a vital resource informing policy makers and the public about the safety of vaccines used in the United States. Large linked databases are used to identify and evaluate adverse events in over 9 million individuals annually. VSD generates rapid, important safety assessments for both routine vaccinations and emergency vaccination campaigns. VSD monitors safety of seasonal influenza vaccines in near-real time, and provided essential information on the safety of influenza A (H1N1) 2009 monovalent vaccine during the recent pandemic. VSD investigators have published important studies demonstrating that childhood vaccines are not associated with autism or other developmental disabilities. VSD prioritizes evaluation of new vaccines; searches for possible unusual health events after vaccination; monitors vaccine safety in pregnant women; and has pioneered development of biostatistical research methods.

A systematic review of validated methods to capture acute bronchospasm using administrative or claims data

PURPOSE

To identify and assess billing, procedural, or diagnosis code, or pharmacy claim-based algorithms used to identify acute bronchospasm in administrative and claims databases.

METHODS

We searched the MEDLINE database from 1991 to September 2012 using controlled vocabulary and key terms related to bronchospasm, wheeze and acute asthma. We also searched the reference lists of included studies. Two investigators independently assessed the full text of studies against pre-determined inclusion criteria. Two reviewers independently extracted data regarding participant and algorithm characteristics.

RESULTS

Our searches identified 677 citations of which 38 met our inclusion criteria. In these 38 studies, the most commonly used ICD-9 code was 493.x. Only 3 studies reported any validation methods for the identification of bronchospasm, wheeze or acute asthma in administrative and claims databases; all were among pediatric populations and only 2 offered any validation statistics. Some of the outcome definitions utilized were heterogeneous and included other disease based diagnoses, such as bronchiolitis and pneumonia, which are typically of an infectious etiology. One study offered the validation of algorithms utilizing Emergency Department triage chief complaint codes to diagnose acute asthma exacerbations with ICD-9 786.07 (wheezing) revealing the highest sensitivity (56%), specificity (97%), PPV (93.5%) and NPV (76%).

CONCLUSIONS

There is a paucity of studies reporting rigorous methods to validate algorithms for the identification of bronchospasm in administrative data. The scant validated data available are limited in their generalizability to broad-based populations.

IgE anti Hepatitis B virus surface antigen antibodies detected in serum from inner city asthmatic and non asthmatic children

Viral Hepatitis type B (HBV) is a public health concern, but has not been linked to asthma. Immunoglobulin (Ig) G is involved in HBV immune responses; less is known about IgE antibodies (Abs) against HBV in asthma. Given the importance of HBV, we sought to determine whether HBV vaccine contributes to asthma in children, by stimulating specific IgE production. Total IgE, IgE- or IgG-anti-HBVs Abs were studied in vaccinated pediatric asthmatics and non asthmatics. We found: (1) total IgE was higher in asthmatics; (2) total IgE did not correlate with IgE anti-HBVs; (3) IgE anti-HBVs did correlate with IgG-anti-HBVs in all subjects; (4)IgE- and IgG-HBVs Abs were similar in both groups; (5) IgE- or IgG anti-HBVs Abs did not correlate with age. Our findings indicate that HBV vaccination induces IgE responses in asthmatics and non asthmatics.

Vaccines for measles, mumps and rubella in children

BACKGROUND

Mumps, measles and rubella (MMR) are serious diseases that can lead to potentially fatal illness, disability and death. However, public debate over the safety of the trivalent MMR vaccine and the resultant drop in vaccination coverage in several countries persists, despite its almost universal use and accepted effectiveness.

OBJECTIVES

To assess the effectiveness and adverse effects associated with the MMR vaccine in children up to 15 years of age.

SEARCH METHODS

For this update we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 2), which includes the Cochrane Acute Respiratory Infections Group's Specialised Register, PubMed (July 2004 to May week 2, 2011) and Embase.com (July 2004 to May 2011).

SELECTION CRITERIA

We used comparative prospective or retrospective trials assessing the effects of the MMR vaccine compared to placebo, do nothing or a combination of measles, mumps and rubella antigens on healthy individuals up to 15 years of age.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed methodological quality of the included studies. One review author arbitrated in case of disagreement.

MAIN RESULTS

We included five randomised controlled trials (RCTs), one controlled clinical trial (CCT), 27 cohort studies, 17 case-control studies, five time-series trials, one case cross-over trial, two ecological studies, six self controlled case series studies involving in all about 14,700,000 children and assessing effectiveness and safety of MMR vaccine. Based on the available evidence, one MMR vaccine dose is at least 95% effective in preventing clinical measles and 92% effective in preventing secondary cases among household contacts.Effectiveness of at least one dose of MMR in preventing clinical mumps in children is estimated to be between 69% and 81% for the vaccine prepared with Jeryl Lynn mumps strain and between 70% and 75% for the vaccine containing the Urabe strain. Vaccination with MMR containing the Urabe strain has demonstrated to be 73% effective in preventing secondary mumps cases. Effectiveness of Jeryl Lynn containing MMR in preventing laboratory-confirmed mumps cases in children and adolescents was estimated to be between 64% to 66% for one dose and 83% to 88% for two vaccine doses. We did not identify any studies assessing the effectiveness of MMR in preventing rubella.The highest risk of association with aseptic meningitis was observed within the third week after immunisation with Urabe-containing MMR (risk ratio (RR) 14.28; 95% confidence interval (CI) from 7.93 to 25.71) and within the third (RR 22.5; 95% CI 11.8 to 42.9) or fifth (RR 15.6; 95% CI 10.3 to 24.2) weeks after immunisation with the vaccine prepared with the Leningrad-Zagreb strain. A significant risk of association with febrile seizures and MMR exposure during the two previous weeks (RR 1.10; 95% CI 1.05 to 1.15) was assessed in one large person-time cohort study involving 537,171 children aged between three months and five year of age. Increased risk of febrile seizure has also been observed in children aged between 12 to 23 months (relative incidence (RI) 4.09; 95% CI 3.1 to 5.33) and children aged 12 to 35 months (RI 5.68; 95% CI 2.31 to 13.97) within six to 11 days after exposure to MMR vaccine. An increased risk of thrombocytopenic purpura within six weeks after MMR immunisation in children aged 12 to 23 months was assessed in one case-control study (RR 6.3; 95% CI 1.3 to 30.1) and in one small self controlled case series (incidence rate ratio (IRR) 5.38; 95% CI 2.72 to 10.62). Increased risk of thrombocytopenic purpura within six weeks after MMR exposure was also assessed in one other case-control study involving 2311 children and adolescents between one month and 18 years (odds ratio (OR) 2.4; 95% CI 1.2 to 4.7). Exposure to the MMR vaccine was unlikely to be associated with autism, asthma, leukaemia, hay fever, type 1 diabetes, gait disturbance, Crohn's disease, demyelinating diseases, bacterial or viral infections.

AUTHORS' CONCLUSIONS

The design and reporting of safety outcomes in MMR vaccine studies, both pre- and post-marketing, are largely inadequate. The evidence of adverse events following immunisation with the MMR vaccine cannot be separated from its role in preventing the target diseases.

Cytokine levels and profiles in children related to sickle cell disease and asthma status

Atopic asthma in patients with sickle cell disease (SCD) is associated with an increased risk of acute chest syndrome (ACS). Cytokine-mediated inflammation might explain this association. Studies of cytokine profiles in patients with SCD have yielded conflicting data, but the possible influence of asthma status has not been examined. Our aim was to test the hypothesis that cytokine levels and profiles in SCD children reflected their asthma status. Samples from 155 Jamaican children (80 had SCD) and 64 British children (53 had SCD) who had their asthma status documented were analyzed for the presence and levels of interleukin 4 (IL-4) and interferon (IFN)-γ; they were also classified by their T helper cell (Th) cytokine profile. Jamaican children with SCD, when compared with Jamaican controls, were more likely to be diagnosed with asthma (P=0.001), more likely to be IL-4 positive (P<0.001), and more likely to be classified as having a Th-2 pattern (<0.001). In contrast, British children with SCD, when compared with the British controls, were less likely to have been diagnosed with asthma (P=0.04) and less likely to be classified as having a Th-2 pattern (P=0.006). Regression analysis demonstrated that amongst Jamaican children, SCD status, but not asthma status, ACS history, or gender, was predictive of IL-4 positivity and Th-2 status (P<0.001). In British children, none of those variables were significant predictors of IL-4 positivity or Th status. Cytokine profiles differed between Jamaican and British children. In the Jamaican children they reflected SCD, but not asthma or ACS status.

Early childhood infections and immunisation and the development of allergic disease in particular asthma in a high-risk cohort: A prospective study of allergy-prone children from birth to six years

The role of early childhood infections and immunisation in the development of allergic diseases remains controversial. To examine these associations, six hundred and twenty infants with first-degree relatives with allergic diseases were recruited into the Melbourne Atopy Cohort Study. Information on risk factors and outcomes was collected by interviewer administered questionnaire and was based on parental report and/or a physician's diagnosis. Risk factors examined included early childhood infections (including gastroenteritis, otitis media and lower respiratory tract infections) and immunisations in the first 2 yr of life. Outcomes were current asthma, allergic rhinitis and eczema at 6 yr of age. Univariate and multivariate regression analysis were used to estimate relative risk (RR) and assess confounding. By 6 yr, 79% of the original cohort remained in the study. Those with at least three episodes of gastroenteritis showed an increased risk (crude RR 2.36, 95%CI 1.41 3.95; adjusted RR 2.03 95%CI 1.50 2.75) for the later development of asthma at age 6. Of the scheduled immunisations, Sabin immunisation in the second year had a reduced risk of asthma at 6 yr (crude RR 0.60, 95%CI 0.37 0.98; adjusted RR 0.63 95%CI 0.39 1.02). Combined diphtheria and tetanus (CDT) immunisation in the first year had an increased risk of asthma at 6 yr (RR 1.76, 95%CI 1.11 2.78; adjusted RR 1.88 95%CI 1.28 2.77). Recurrent gastroenteritis in early childhood is associated with a later risk of asthma. This may reflect a cause and effect relationship, or exposure to common risk factors. In contrast, Sabin immunisation in the second year is associated with a decreased risk of asthma in later childhood. CDT immunisation in the first year may be a risk factor for asthma, but the need for CDT immunisation may also be a marker of increased risk of asthma in later childhood.

Asthma prevalence and exacerbations in children: is there an association with childhood vaccination?

Infections and vaccinations may have a potential role in the normal maturation of the immune system, in the development and balance of regulatory pathways, and in the development and exacerbations of asthma. Asthma exacerbations often result from respiratory viral infections, and, while vaccination towards common viral infections may reduce the occurrence of such exacerbations, there has been concern that vaccinations can increase the risk of asthma. Current studies show that childhood vaccines, including inactivated influenza vaccine, are generally safe. However, there is some concern regarding possible exacerbations in infants or children with frequent wheezing or persistent asthma who are given live-attenuated influenza vaccination. Although severe allergic adverse events attributable to vaccination are extremely rare, all serious allergic reactions should be further assessed to detect the likely causative vaccine component, such as egg protein or gelatin. The risks of not vaccinating children far outweigh the risks of allergy and asthma exacerbations. Therefore, childhood vaccination should remain an essential part of child health programs and should not be withheld, even from children with asthma or those predisposed to allergy.

Childhood immunization and atopic disease into middle-age--a prospective cohort study

The association between childhood immunizations and risk of atopic diseases is unclear. No study has examined possible associations between childhood immunizations and such diseases in middle age. The Tasmanian Longitudinal Health Study (TAHS) is a population based cohort study of respiratory disease. The TAHS participants were followed from 7 to 44 yrs of age. Immunizations during childhood were examined for any association with asthma and atopic disease at age 44 yrs. Multivariable regression models were used to estimate relative risks while adjusting for confounders. Cox regression was used to estimate the association between childhood immunizations and asthma developing after the age of 7 yrs. We found no association between any childhood immunization (Diphtheria, Tetanus, Pertussis, Polio, Smallpox) and asthma (ORs ranged from 0.87 to 1.17 p > 0.05), eczema (ORs ranged from 0.99 to 1.07 p > 0.05), food allergy (ORs ranged from 0.97 to 1.11 p > 0.05), or hay fever (ORs ranged from 1.02 to 1.05 p > 0.05) at age 44. Nor did we find any association between childhood immunizations and an increased risk of incident asthma after the age of 7 yrs (Diphtheria HR = 1.06, 95% CI 0.82, 1.36; Tetanus HR = 1.13, 95% CI 0.88, 1.44; Pertussis HR = 1.03, 95% CI 0.81, 1.30; Polio HR = 1.15, 95% CI 0.86, 1.54; Smallpox HR = 1.21, 95% CI 0.99, 1.48; DTP HR = 1.05, 95% CI 0.85, 1.30). Our analysis does not support any association between common childhood immunizations and risk of asthma and atopic disease in middle-age. Our findings should provide reassurance that in terms of life time risk of asthma and atopic disease, childhood immunization is safe.

Knowledge synthesis of benefits and adverse effects of measles vaccination: the Lasbela balance sheet

Background

In preparation for a cluster-randomized controlled trial of a community intervention to increase the demand for measles vaccination in Lasbela district of Pakistan, a balance sheet summarized published evidence on benefits and possible adverse effects of measles vaccination.

Methods

The balance sheet listed: 1) major health conditions associated with measles; 2) the risk among the unvaccinated who contract measles; 3) the risk among the vaccinated; 4) the risk difference between vaccinated and unvaccinated; and 5) the likely net gain from vaccination for each condition.

Results

Two models revealed very different projections of net gain from measles vaccine. A Lasbela-specific combination of low period prevalence of measles among the unvaccinated, medium vaccination coverage and low vaccine efficacy rate, as revealed by the baseline survey, resulted in less-than-expected gains attributable to vaccination. Modelled on estimates where the vaccine had greater efficacy, the gains from vaccination would be more substantial.

Conclusion

Specific local conditions probably explain the low rates among the unvaccinated while the high vaccine failure rate is likely due to weaknesses in the vaccination delivery system. Community perception of these realities may have had some role in household decisions about whether to vaccinate, although the major discouraging factor was inadequate access. The balance sheet may be useful as a communication tool in other circumstances, applied to up-to-date local evidence.

Virus vaccines and children with asthma

PURPOSE OF REVIEW

To describe what is currently known about the role of virus vaccines in the pathogenesis of asthma and atopy and summarize their role in the prevention of morbidity due to childhood asthma.

RECENT FINDINGS

The development of virus vaccines and their incorporation into infant and childhood immunization programmes over the last few decades of the twentieth century have been accompanied by a striking concomitant rise in the incidence of asthma and atopy. However, a causal relationship is not supported by the majority of observational studies. The role of childhood immunization against respiratory viruses in the reduction of morbidity from asthma is another important public health issue. Recent findings suggest that influenza is not strongly associated with exacerbations of asthma in children, despite recommendations that this group should be immunized against it.

SUMMARY

Current evidence suggests that virus vaccination is well tolerated and does not lead to an increased incidence of asthma or atopy in children receiving vaccines. Debate continues regarding the place of respiratory virus vaccination in the therapeutic armamentarium for children with asthma. In the case of influenza, there appears to be an absence of harm, but benefit seems to be limited to younger children.

Breastfeeding is an essential complement to vaccination

AIM

This article explores the role of breastfeeding in different aspects of vaccination in the first 6 months when infants are still developing: (1) pain management; (2) immunomodulation of infants' vaccine responses; (3) metabolism of thimerosal.

METHODS

Major databases were searched for studies that addressed outcomes of related issues.

RESULTS

Studies reveal that breastfeeding can: (1) help mothers and infants to cope with the stressful situations that accompany parenteral vaccines; (2) improve response to vaccines in the still maturing immunologic and enterohepatic systems of infants; (3) influence physiologic parameters that can change metabolism of ethylmercury derived from some vaccines.

CONCLUSION

Health promotion that supports vaccinations should also emphasize early initiation and maintenance of exclusive breastfeeding up until 6 months for maximum protection of the infants with a possible beneficial effect on the vaccine response. Paediatric professionals should inform mothers of the proven benefits of breastfeeding and its importance in complementing vaccination and lowering stress and the risk of untoward reactions on susceptible infants.

Allergic disease and atopic sensitization in children in relation to measles vaccination and measles infection

OBJECTIVE

Our aim was to investigate the role of measles vaccination and measles infection in the development of allergic disease and atopic sensitization.

METHODS

A total of 14 893 children were included from the cross-sectional, multicenter Prevention of Allergy-Risk Factors for Sensitization in Children Related to Farming and Anthroposophic Lifestyle study, conducted in 5 European countries (Austria, Germany, the Netherlands, Sweden, and Switzerland). The children were between 5 and 13 years of age and represented farm children, Steiner-school children, and 2 reference groups. Children attending Steiner schools often have an anthroposophic (holistic) lifestyle in which some immunizations are avoided or postponed. Parental questionnaires provided information on exposure and lifestyle factors as well as symptoms and diagnoses in the children. A sample of the children was invited for additional tests, and 4049 children provided a blood sample for immunoglobulin E analyses. Only children with complete information on measles vaccination and infection were included in the analyses (84%).

RESULTS

In the whole group of children, atopic sensitization was inversely associated with measles infection, and a similar tendency was seen for measles vaccination. To reduce risks of disease-related modification of exposure, children who reported symptoms of wheezing and/or eczema debuting during first year of life were excluded from some analyses. After this exclusion, inverse associations were observed between measles infection and "any allergic symptom" and "any diagnosis of allergy by a physician." However, no associations were found between measles vaccination and allergic disease.

CONCLUSION

Our data suggest that measles infection may protect against allergic disease in children.

Routine vaccination against pertussis and the risk of childhood asthma: a population-based cohort study

BACKGROUND

In industrialized countries vaccination coverage remains suboptimal, partly because of perception of an increased risk of asthma. Epidemiologic studies of the association between childhood vaccinations and asthma have provided conflicting results, possibly for methodologic reasons such as unreliable vaccination data, biased reporting, and reverse causation. A recent review stressed the need for additional, adequately controlled large-scale studies.

OBJECTIVE

Our goal was to determine if routine childhood vaccination against pertussis was associated with subsequent development of childhood wheezing disorders and asthma in a large population-based cohort study.

METHODS

In 6811 children from the general population born between 1993 and 1997 in Leicestershire, United Kingdom, respiratory symptom data from repeated questionnaire surveys up to 2003 were linked to independently collected vaccination data from the National Health Service database. We compared incident wheeze and asthma between children of different vaccination status (complete, partial, and no vaccination against pertussis) by computing hazard ratios. Analyses were based on 6048 children, 23 201 person-years of follow-up, and 2426 cases of new-onset wheeze.

RESULTS

There was no evidence for an increased risk of wheeze or asthma in children vaccinated against pertussis compared with nonvaccinated children. Adjusted hazard ratios comparing fully and partially vaccinated with nonvaccinated children were close to one for both incident wheeze and asthma.

CONCLUSION

This study provides no evidence of an association between vaccination against pertussis in infancy and an increased risk of later wheeze or asthma and does not support claims that vaccination against pertussis might significantly increase the risk of childhood asthma.

Measles-mumps-rubella vaccination and asthma-like disease in early childhood

The authors evaluated the association between receipt of measles-mumps-rubella (MMR) vaccine and asthma-like disease in early childhood in a Danish nationwide cohort study (N = 871,234). Two outcomes were included: hospitalizations with asthma diagnoses and use of anti-asthma medications (for a subset of the cohort only). Poisson regression was used to estimate rate ratios according to vaccination status. MMR-vaccinated children were less often hospitalized with an asthma diagnosis (rate ratio (RR) = 0.75, 95% confidence interval (CI): 0.73, 0.78) and used fewer courses of anti-asthma medication (RR = 0.92, 95% CI: 0.91, 0.92) than unvaccinated children. This "protective" effect of MMR vaccine was more pronounced for hospitalizations with severe asthma diagnoses (status asthmaticus: RR = 0.63, 95% CI: 0.49, 0.82) and use of medication that was highly specific for asthma (long-acting beta2-agonist inhalant: RR = 0.68, 95% CI: 0.63, 0.73). MMR vaccine was not negatively associated with anti-asthma medications often used for wheezing illnesses in early childhood (systemic beta2-agonist: RR = 1.02, 95% CI: 1.01, 1.02). These results are compatible not with an increased risk of asthma following MMR vaccination but rather with the hypothesis that MMR vaccination is associated with a reduced risk of asthma-like disease in young children.

Do different vaccination regimens for BCG and hepatitis B affect the development of allergic disorders in early childhood?

AIM

To determine whether age at bacilli Calmette-Guérin (BCG) and hepatitis B vaccination has an effect on the development of atopy and allergic disorders in early childhood.

METHODS

This was a cross-sectional study of 109 children aged between 24 and 36 months with respiratory system diseases. The study population was divided into two groups according to vaccination regimens: group 1, beginning hepatitis B vaccination at birth and receiving BCG vaccine at two months of age; group 2, receiving BCG vaccine at birth and beginning hepatitis B vaccination at two months of age. Atopic status was assessed by skin-prick tests (SPTs).

RESULTS

There was no statistically significant difference in atopy between two groups (p = 0.27). However, the prevalence of recurrent wheezing was higher in group 1 (36.4%) than group 2 (16.3%) (p = 0.04). Logistic regression analysis identified receiving BCG vaccine at birth and beginning hepatitis B vaccination at the age of two months were protective for recurrent wheezing (odds ratio 0.5; confidence interval: 0.3-0.8; p = 0.01).

CONCLUSION

We believe that the administration of BCG vaccine at birth and hepatitis B vaccine at two months may be protective against recurrent wheezing but doesn't prevent atopy.

Environmental factors and allergic disorders

Despite numerous studies on possible associations between environmental exposure and allergic disorders, any conclusions made remain a matter of controversy. We conducted a review of evidence in relation to environmental and nutritional determinants and wheeze, asthma, atopic dermatitis, and allergic rhinitis. Identified were 263 articles for analysis after consideration of 1093 papers that were published since 2000 and selected by electronic search of the PubMed database using keywords relevant to epidemiological studies. Most were cross-sectional and case-control studies. Several prospective cohort studies revealed inconsistent associations between various environmental factors and the risk of any allergic disorder. Therefore, the evidence was inadequate to infer the presence or absence of a causal relationship between various environmental exposures and allergic diseases. However, evidence is suggestive of positive associations of allergies with heredity. Because almost all the studies were performed in Western countries, the application of these findings to people in other countries, including Japan, may not be appropriate. Further epidemiological information gained from population-based prospective cohort studies, in particular among Japanese together with other Asians, is needed to assess causal relationships between various environmental factors and allergic diseases.

Is childhood vaccination associated with asthma? A meta-analysis of observational studies

BACKGROUND

The possible link between immunization and atopic diseases has been under intense debate in the last decade.

OBJECTIVE

The aim of this study was to systematically review the available evidence on the association of whole-cell pertussis and BCG vaccination with the risk of asthma in childhood and adolescence.

METHODS

The major medical electronic databases (Medline, National Library of Medicine Gateway, and Cochrane Library) were searched, and reference lists of the relevant publications were reviewed for relevant birth-cohort studies and randomized, controlled trials from 1966 to March 2006. Only studies that directly compared vaccinated and unvaccinated children, validated vaccination status by medical charts, and used preset criteria to define asthma were included. Data were abstracted by using a standardized protocol and computerized report form. Results were analyzed by applying a fixed-effect or random-effect model, according to the heterogeneity of the studies. Sensitivity analyses by scoring criteria were performed.

RESULTS

Seven studies of pertussis vaccination (with a total of 186,663 patients) and 5 studies of BCG vaccination (with a total of 41,479 patients) met our inclusion criteria. No statistically significant association was detected between either whole-cell pertussis or BCG vaccination and incidence rates of asthma during childhood and adolescence. This lack of a significant association proved to be robust on sensitivity analyses for BCG but not for pertussis vaccine.

CONCLUSIONS

Currently available data, based on observational studies, do not support an association, provocative or protective, between receipt of the BCG or whole-cell pertussis vaccine and risk of asthma in childhood and adolescence.

The complex link between immunization against childhood diseases and allergy

Vaccines can be at the origin of allergic manifestations in susceptible children. Such manifestations include: immediate-type hypersensitivity (anaphylactic shock, rash or angioedema) within 1 h after the injection; semi-late hypersensitivity (local inflammatory lesion such as the Arthus phenomenon) a few hours after the injection; and delayed-type hypersensitivity (abscess or eczema at the site of the injection). Furthermore, early-life vaccinations have been implicated in the modulation of the immune system as they could promote the development of allergy by avoiding infections. However, most population-based studies have not found an increased risk of allergies in vaccinated children. Due to methodological problems in conducting the studies, further investigations are needed to better understand the phenomenon.

Immunogenicity, efficacy, safety and effectiveness of pneumococcal conjugate vaccines (1998–2006)

In this paper we present an overview of the literature on efficacy and safety trials of the various pneumococcal conjugate vaccines on the market (PCV7) and in development (PCV9, PCV11 and allegedly PCV10 and PCV13), as well as of observations from post-licensure studies. Seven- (PCV7) and nine-valent PCV (PCV9) are reported to be sufficiently immunogenic after administration of a 3+1 schedule in infants in various RCTs. PncOMPC (PCV7 with a protein of N. meningitidis as a carrier) is less immunogenic, though this may have no repercussions for the protective efficacy against clinical disease. PCV7 is 82-97% efficacious against vaccine serotype (VT) IPD, 90% efficacious against (clinically diagnosed) pneumococcal pneumonia, and, like the 11-valent PCV, 57% efficacious against VT acute otitis media. Naturally, it would be of paramount public health interest if the same levels of efficacy and effectiveness could be achieved with fewer doses. Trials studying 2+1 vaccination schedules for PCV7 and PCV9 generally show that the percentage of infants achieving the protective cut-off set by the World Health Organization (WHO) 1 month after the last priming dose, is comparable to that found at the same time point in studies administering 3+1 schedules. PCVs are generally very well tolerated and safe, also when co-administered with other childhood vaccines. As more and more countries are using these vaccines routinely, post marketing surveillance studies will further establish the safety profile of PCVs.

Early BCG and pertussis vaccination and atopic diseases in 5- to 7-year-old preschool children from Augsburg, Germany: results from the MIRIAM study

The role of immunization in the development of atopic disorders is still under debate. One reason might be, that because of high vaccination coverage in most countries only few and selected children are not immunized, leading to unstable and often biased effect estimates. In Germany, the situation was different between 1985 and 1991: bacillus Calmette-Guérin (BCG) and pertussis vaccination were not officially recommended leading to high numbers of non-vaccinated children in the 1990s. We report on a cross-sectional study with 1673 participants among 5- to 7-year-old preschool children conducted in 1996. We found no hint that BCG vaccination or whole-cell pertussis (WCP) vaccination may lead to higher prevalences of asthma, allergic rhinitis, eczema or allergic sensitization at preschool age. None of the associations was significantly positive. WCP vaccination may be protective against asthma OR 0.55 (95% CI: 0.31-0.98) and against symptoms of eczema in boys.

Diphtheria, pertussis, poliomyelitis, tetanus, and Haemophilus influenzae type b vaccinations and risk of eczema and recurrent wheeze in the first year of life: the KOALA Birth Cohort Study

OBJECTIVES

Among potential etiologic factors for atopic manifestations, infant vaccinations have recently been discussed. We evaluated in a prospective design whether infants who were unvaccinated or vaccinated according to incomplete vaccination schedules in the first 6 months of age were at decreased risk for eczema and recurrent wheeze in the first year of life.

METHODS

Information on vaccinations against diphtheria, pertussis, poliomyelitis, tetanus; Haemophilus influenzae type b vaccine; and eczema and recurrent wheeze was collected by repeated questionnaires in 2764 families participating in the KOALA Birth Cohort Study in The Netherlands. A standard vaccination schedule referred to 3 diphtheria, pertussis, poliomyelitis, tetanus, and Haemophilus influenzae type b vaccinations in the first 6 months with the first given in months 1 to 3; an incomplete vaccination schedule was defined as any other vaccination schedule. Exclusion criteria were prematurity (gestational age <37 weeks) and congenital abnormalities related to immunity (such as Down syndrome). Multiple logistic regression models were fitted to adjust for confounding factors.

RESULTS

During the first year of life, the incidence of eczema was 23% (584 of 2537 infants) and of recurrent wheeze, the incidence was 8.5% (203 of 2402 infants). At age 6 months, 1969 (77%) of 2545 infants had been vaccinated according to a standard schedule, 393 (15%) vaccinated according to an incomplete schedule, and 182 (7%) never vaccinated. Compared with infants with standard vaccination schedules, infants with incomplete schedules did not differ significantly in eczema risk or recurrent wheeze. This was also true for infants who had never been vaccinated.

CONCLUSION

This study shows that the risk of eczema or recurrent wheeze at 1 year of age does not differ between infants with different vaccination status at the age of 6 months.

Do vaccines modify the prevalence of asthma and allergies?

Epidemiological studies suggest the hypothesis that the increase in asthma and allergies in the industrialized world can be explained by a decline in the number of infectious diseases occurring during childhood. In the context of this 'hygiene hypothesis', is immunization in early life a risk factor for promoting allergic diseases? The majority of studies, especially those conducted with more extensive populations, have not found an increased risk, and although 'not finding an increased risk' is not the same as 'the non-existence of any risk at all', it seems that the evidence is tipped in favor of the absence of risk. Conversely, although some surveys have described a protective effect of vaccination, the majority refuted this result. If there is any effect, it is probably a weak one.