Immunization and symptoms of atopic disease in children: results from the International Study of Asthma and Allergies in Childhood

Association between vaccination, viral antibodies, and asthma prevalence in the U.S.: insights from NHANES (1999-2020)

Objective

This investigation aimed to explore the differences in asthma prevalence among various demographic groups in the U.S., focusing on factors related to vaccination and viral antibodies.

Methods

The study analyzed data from 37,445 individuals collected through the National Health and Nutrition Examination Survey between 1998 and 2020. Employing weighted sampling methods, the analysis considered the stratification and clustering typical of the survey's design. It particularly examined how age, race, income, smoke, education, and gender factors influence both the prevalence and severity of asthma.

Results

This study aims to elucidate disparities in asthma prevalence across the U.S. population by examining the roles of demographic characteristics and factors related to vaccination and viral antibodies. It revealed a significant correlation between asthma prevalence and patient demographics, including age, gender, income, smoke, education, and race. We found that asthma patients were mostly found in participants with lower economic level (2.7 vs. 2.87). Non-Hispanic black women age exhibited a higher likelihood of asthma, at 17.7%, compared to non-Hispanic whites and Mexican Americans. Asthma prevalence peaks between the ages of 20 and 30 and has shown a rising trend over the years. Regarding vaccinations, hepatitis A, hepatitis B, pneumococcal, and HPV vaccines were associated with an increased risk of asthma. Conversely, patients testing positive for hepatitis A virus and core hepatitis B virus antibodies demonstrated a lower prevalence of asthma. Additionally, asthmatic patients showed lower average measles virus and rubella antibodies levels, at 0.53 and 3.32, respectively, compared to non-asthmatic individuals. Notably, asthma incidence was lower in herpesvirus I-positive patients (OR: 0.895, CI, 0.809%-0.991%), while herpesvirus II-positive patients displayed a higher incidence of asthma (OR: 1.102, CI, 0.974%-1.246%).

Conclusion

The study findings underscore the significant prevalence of asthma and its correlation with population demographics, vaccination rates, and serum viral antibodies. These results highlight the importance of implementing tailored public health interventions.

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.

Recommendations for Vaccination in Children with Atopic Dermatitis Treated with Dupilumab: A Consensus Meeting, 2020

Dupilumab is the only biologic therapy currently approved in Europe and the United States for severe atopic dermatitis in patients 6 years of age or older. Off-label use is rationalized in younger children with severe atopic dermatitis. Decisions about vaccination for children on dupilumab are complex and depend on both the child's current treatment and the type of vaccination required. To achieve consensus on recommendations for vaccination of pediatric patients with atopic dermatitis treated with or planning to start dupilumab, a review of the literature and a modified-Delphi process was conducted by a working group of 5 panelists with expertise in dermatology, immunology, infectious diseases and vaccination. Here, we provide seven recommendations for vaccination of pediatric patients with atopic dermatitis treated with or planning to start dupilumab. These recommendations serve to guide physicians' decisions about vaccination in children with atopic dermatitis treated with dupilumab. Furthermore, we highlight an unmet need for research to determine how significantly dupilumab affects cellular and humoral immune responses to vaccination with live attenuated and inactivated vaccines.

Vaccines do not cause atopic dermatitis: A systematic review and meta-analysis

BACKGROUND

Previous studies found conflicting results about the association of vaccinations and likelihood of atopic dermatitis (AD).

OBJECTIVES

To determine whether vaccinations increase the likelihood of AD.

METHODS

A systematic review was performed of all published studies in MEDLINE, EMBASE, LILACS, Scopus, and Web of Science databases. At least 2 reviewers conducted title/abstract, full-text review, and data extraction. Quality of evidence was assessed using the Newcastle-Ottawa Scale (NOS).

RESULTS

Forty-four studies met inclusion criteria; 37 had sufficient data for meta-analysis. There were no associations any vaccine regimen (random-effects logistic regression: odds ratio [95% confidence interval]: 0.961 [0.822-1.124]; n = 21 studies) BCG (0.927 [0.701-1.226]; n = 8), pertussis (0.790 [0.416-1.499]; n = 4), single (1.031 [0.920-1.155]; n = 17) or multiple vaccines (0.902 [0.608-1.338]; n = 7) with likelihood of AD. This remained true in studies with high-quality (NOS ≥ 7) (OR [95% CI]: 0.941 [0.793-1.117]; n = 13 studies) or low-quality (NOS < 7) (OR [95% CI]: 1.058 [0.669-1.674]; n = 8 studies).

LIMITATIONS

No randomized controlled trials.

CONCLUSIONS

No vaccine regimen was consistently associated with developing AD.

Analysis of health outcomes in vaccinated and unvaccinated children: Developmental delays, asthma, ear infections and gastrointestinal disorders

OBJECTIVE

The aim of this study was to compare the health of vaccinated versus unvaccinated pediatric populations.

METHODS

Using data from three medical practices in the United States with children born between November 2005 and June 2015, vaccinated children were compared to unvaccinated children during the first year of life for later incidence of developmental delays, asthma, ear infections and gastrointestinal disorders. All diagnoses utilized International Classification of Diseases-9 and International Classification of Diseases-10 codes through medical chart review. Subjects were a minimum of 3 years of age, stratified based on medical practice, year of birth and gender and compared using a logistic regression model.

RESULTS

Vaccination before 1 year of age was associated with increased odds of developmental delays (OR = 2.18, 95% CI 1.47-3.24), asthma (OR = 4.49, 95% CI 2.04-9.88) and ear infections (OR = 2.13, 95% CI 1.63-2.78). In a quartile analysis, subjects were grouped by number of vaccine doses received in the first year of life. Higher odds ratios were observed in Quartiles 3 and 4 (where more vaccine doses were received) for all four health conditions considered, as compared to Quartile 1. In a temporal analysis, developmental delays showed a linear increase as the age cut-offs increased from 6 to 12 to 18 to 24 months of age (ORs = 1.95, 2.18, 2.92 and 3.51, respectively). Slightly higher ORs were also observed for all four health conditions when time permitted for a diagnosis was extended from ⩾ 3 years of age to ⩾ 5 years of age.

CONCLUSION

In this study, which only allowed for the calculation of unadjusted observational associations, higher ORs were observed within the vaccinated versus unvaccinated group for developmental delays, asthma and ear infections. Further study is necessary to understand the full spectrum of health effects associated with childhood vaccination.

Whole-cell pertussis vaccine (DTwP) has no influence on allergic diseases and atopic sensitization in children

Introduction

Vaccine opponents indicate that the infant’s immune system is inadequately developed to handle multiple vaccines which may overwhelm the immune system, leading to allergic diseases.

Aim

To verify the association between the vaccine antigen overload derived from DTwP and the development of atopic sensitization and allergic diseases.

Material and methods

Data from an earlier established birth cohort in Krakow, followed up to the 6^th year of life were used. Allergic diseases such as eczema, hay fever and asthma were diagnosed by a physician and reported every half a year from the 1^st to 6^th year of life by the child’s parent. Skin prick tests (SPT) were performed in children at 5 years of age. The data on infants’ vaccination were extracted from the physician’s records. The status of vaccine antigen exposure was based on different types of vaccines against pertussis (DTwP or DTaP) in a primary course. Results were determined by multiple logistic regression, adjusted to potential confounders.

Results

The analyzed population consisted of 234 children: 53.4% – boys and 46.6% – girls. Infants up to the age of 8 months were vaccinated with the primary course against pertussis, with DTwP – 60.7%, DTaP – 32.9% and further 6.4% with a mixed course (DTwP + DTaP). There were no significant relationships between any of vaccination groups and allergic disease and allergen sensitivity in the multiple logistic regression model with adjustment to potential confounders.

Conclusions

The exposure to a large number of vaccine antigens derived from DTwP has no influence on the development of allergic diseases and atopic sensitization in children.

Role of primary and secondary prevention in atopic dermatitis

Atopic dermatitis (AD) is a serious epidemiological problem in industrialized countries. The incidence of AD has increased considerably over the last 30 years. Atopic dermatitis is a chronic, recurrent, inflammatory skin disease accompanied by strong itching. It is characterized by typical features depending on age. The parents of children suffering from AD must be prepared to change their lifestyle. They should avoid factors which can promote skin lesions and apply appropriate, regular skin care. The article describes primary prevention of AD as well as prophylactic measures to avoid skin eczema. It presents the role of infections, vaccinations, breastfeeding and the influence of domestic animals, house renovation and moulds on development of AD. The article also describes the significance of the epidermal barrier, skin colonization by microbial agents, pruritus, stress, food and inhalant allergy among people who suffer from AD.

The Role of Human Milk Immunomodulators in Protecting Against Viral Bronchiolitis and Development of Chronic Wheezing Illness

Infants who are breastfed are at an immunological advantage when compared with formula fed infants, evidenced by decreased incidence of infections and diminished propensity for long term conditions, including chronic wheeze and/or asthma. Exclusive breastfeeding reduces the duration of hospital admission, risk of respiratory failure and requirement for supplemental oxygen in infants hospitalised with bronchiolitis suggesting a potentially protective mechanism. This review examines the evidence and potential pathways for protection by immunomodulatory factors in human milk against the most common viral cause of bronchiolitis, respiratory syncytial virus (RSV), and subsequent recurrent wheeze in infants. Further investigations into the interplay between respiratory virus infections such as RSV and how they affect, and are affected by, human milk immunomodulators is necessary if we are to gain a true understanding of how breastfeeding protects many infants but not all against infections, and how this relates to long-term protection against conditions such as chronic wheezing illness or asthma.

Asthma in children and adolescents in Brazil: contribution of the International Study of Asthma and Allergies in Childhood (ISAAC)

Objective:

To assess asthma among Brazilian pediatric population applying the International Study of Asthma and Allergies in Childhood (ISAAC), an internationally standardized and validated protocol.

Data sources:

ISAAC was conceived to maximize the value of epidemiologic studies on asthma and allergic diseases, establishing a standardized method (self-applicable written questionnaire and/or video questionnaire) capable to facilitate the international collaboration. Designed to be carried out in three successive and dependent phases, the ISAAC gathered a casuistic hitherto unimaginable in the world and in Brazil. This review included data gathered from ISAAC official Brazilian centers and others who used this method.

Data synthesis:

At the end of the first phase, it has been documented that the prevalence of asthma among Brazilian schoolchildren was the eighth among all centers participating all over the world. Few centers participated in the second phase and investigated possible etiological factors, especially those suggested by the first phase, and brought forth many conjectures. The third phase, repeated seven years later, assessed the evolutionary trend of asthma and allergic diseases prevalence in centers that participated simultaneously in phases I and III and in other centers not involved in phase I.

Conclusions:

In Brazil, the ISAAC study showed that asthma is a disease of high prevalence and impact in children and adolescents and should be seen as a Public Health problem. Important regional variations, not well understood yet, and several risk factors were found, which makes us wonder: is there only one or many asthmas in Brazil?

Bacille Calmette-Guérin vaccination is associated with lower prevalence of allergic diseases in Indian children

BACKGROUND

Immunization with bacille Calmette-Guérin (BCG) has been shown to augment T helper (Th) 1 biased response and hence gives protection against developing allergies. However, results across the studies have been inconclusive and there is no Indian study verifying this association. We explored the link between BCG vaccination and prevalence of allergic diseases among school children of Chandigarh, North India.

METHODS

In a large cross-sectional study, children aged 7-14 years, with and without documentation and/or scar consistent with BCG vaccination, were examined over a period of 2 years and 5 months with the help of a questionnaire-based survey followed by skin-prick test (SPT).

RESULTS

A total of 10,028 children were included. The mean age was 11.04 ± 2.8 years and M/F ratio was 1.1:1. Among them, 77.7% had documentation of BCG vaccination, 17% had a BCG-like scar but no documentation and 5.3% had no scar/documentation. SPT was performed on 1614 (16%) children. In the BCG group (vaccination and/or scar) 16.7% were atopic (positive SPT) compared with 21.3% in no BCG (no vaccination/scar). The prevalence of allergic diseases among BCG(+) subjects was 10.1%. Among these, asthma was the commonest one (6.1%), followed by rhinitis (3.5%) and eczema (0.5%). There was significant negative correlation between BCG positivity, atopy (p = 0.037), and allergic diseases as a whole (p = 0.028), but on independent analysis the negative correlation was strongest with allergic rhinitis (p = 0.011).

CONCLUSION

BCG vaccination is associated with lower prevalence of allergic disorders in Indian children.

Clinical efficacy and laboratory improvement of bacillus calmette-guerin vaccination on adult atopic asthma: a cohort study

Background

Recent studies have shown that Bacillus Calmette-Guerin (BCG) vaccination is inversely related to asthma, a Th2 cell-associated with allergic disease, which BCG in humans induces Th1-cell immune responses and prevents airway remodeling.

Objective

To investigate whether thrice BCG vaccinations are clinically effective and could induce laboratory improvement compared with placebo on phase 1 (12 weeks) and single BCG vaccination on phase 2 of the study, then finding out whether the effect might last until 9 months after thrice vaccination and 9 months after single vaccination on adult atopic extrinsic asthma.

Methods

According to the Global Initiative for Asthma criteria, 40 mild to moderate persistent atopic asthma patients were randomly assigned in a double-blind fashion into groups that received intra-dermal injection of 0.1 mL of BCG (n = 20) or 0.1 mL of placebo (n = 20) on the first day. On the first phase, subjects on BCG vaccinations were given intradermal injections 3 times on the deltoid region every 4 weeks. On the second phase, at the 12th week, the placebo group was given BCG vaccination once, and this group became the single BCG group. The symptom score (SS) and drug score (DS), lung function, eosinophil blood count (EBC), total serum immunoglobulin E, interferon-γ (IFN-γ), interleukin 4, and transforming growth factor-β1 (TGF-β1) were examined on the first phase (before the treatment and at the 12th week) and on the second phase (on the sixth and ninth months after the third vaccination for thrice BCG group or after single BCG for control group) to monitor the efficacy.

Results

There were some improvements of asthma SS (P < 0.05) and DS (P < 0.05), forced expiratory volume in 1 second (P < 0.05), peak expiratory flow rate (P < 0.05), EBC (P > 0.05), IFN-γ (P < 0.05), and TGF-β1 (P < 0.05) on thrice BCG group compared with prevaccination and with placebo on the first phase and second phase of the study compared with single BCG (formerly placebo).

Conclusions

Based on the previous findings, we could confirm that thrice BCG vaccinations proved to be better than the placebo group and single vaccination. The efficacy of thrice BCG vaccinations on asthma was detected by the improvement of SS, DS, forced expiratory volume in 1 second, peak expiratory flow rate, EBC, IFN-γ, and TGF-β1 until 9 months from the last vaccination without any side effects.

Association of pertussis and measles infections and immunizations with asthma and allergic sensitization in ISAAC Phase Two

BACKGROUND

Pertussis and measles infection as well as vaccination have been suspected as possible mediating factors of allergic disease in childhood.

METHODS

Between 1995 and 2005 cross-sectional studies were performed in 29 centers in 21 countries. Parental questionnaires were used to collect information on allergic diseases and exposures. We analyzed data from 54,943 randomly selected schoolchildren aged 8-12 yr. A subgroup of 31,759 children was also skin prick tested (SPT) to common environmental allergens. Combined odds ratios were calculated by random effect models for meta-analysis.

RESULTS

Pertussis and measles vaccination were not significantly associated with any of the allergy outcomes or SPT positivity. However, pertussis infection was associated with wheeze (OR(ad) 1.68; 95% CI 1.44-1.97) and rhinoconjunctivitis (OR(ad) 1.63; 95% 1.33-2.00). Pertussis infection was also significantly associated with a higher prevalence of reported eczema during the past year in non-affluent countries. Measles infection was associated with a higher prevalence of wheeze (OR(ad) 1.26; 95% 1.10-1.43) and reported eczema (OR(ad) 1.22; 95% 1.08-1.39). No association with SPT positivity was found, suggesting that these associations are unlikely to be mediated by an allergic component.

CONCLUSIONS

Associations of pertussis and measles infection with symptoms of asthma, rhinoconjunctivitis and eczema were found in both affluent and non-affluent countries and are unlikely to be mediated by IgE.

How aluminum adjuvants could promote and enhance non-target IgE synthesis in a genetically-vulnerable sub-population

Aluminum-containing adjuvants increase the effectiveness of vaccination, but their ability to augment immune responsiveness also carries the risk of eliciting non-target responses, especially in genetically susceptible individuals. This study reviews the relevant actions of aluminum adjuvants and sources of genetic risk that can combine to adversely affect a vulnerable sub-population. Aluminum adjuvants promote oxidative stress and increase inflammasome activity, leading to the release of IL-1β, IL-18, and IL-33, but not the important regulatory cytokine IL-12. In addition, they stimulate macrophages to produce PGE₂, which also has a role in regulating immune responses. This aluminum-induced cytokine context leads to a T(H)2 immune response, characterized by the further release of IL-3, IL-4, IL-5, IL-9, IL-13, and IgE-potentiating factors such as sCD23. Genetic variants in cytokine genes, such as IL-4, IL-13, IL-33, and IL-18 influence the response to vaccines in children and are also associated with atopy. These genetic factors may therefore define a genetically-vulnerable sub-population, children with a family history of atopy, who may experience an exaggerated T(H)2 immune response to aluminum-containing vaccines. IL-4, sCD23, and IgE are common factors for both atopy and the immune-stimulating properties of aluminum adjuvants. IL-4 is critical in the production of IgE and total IgE up-regulation. IL-4 has also been reported to induce the production of sCD23 and trigger resting sIgM+, sIgD+ B-cells to switch to sIgE+ B-cells, making them targets for IgE-potentiating factors. Further, the actions of IgE-potentiating factors on sIgE+ B-cells are polyclonal and unrestricted, triggering their differentiation into IgE-forming plasma cells. These actions provide a mechanism for aluminum-adjuvant promotion and enhancement of non-target IgE in a genetically vulnerable sub-population. Identification of these individuals may decrease the risk of adverse events associated with the use of aluminum-containing vaccines.

Is the asthma epidemic still ascending?

Asthma is a phenotypically heterogeneous disorder of multifactorial origins that affects 300 million people suffering from asthma and more than 250,000 asthma-related deaths each year. Although treatment for asthma has improved, its prevalence continues to increase, particularly in low and middle income countries, or in some ethnic groups in which prevalence was previously low. Observed spatio-temporal variations in the increased prevalence of asthma depend on exposure to environmental factors. Recently, several arguments are also in favor of the involvement of host susceptibility and stress in the observed increase of asthma prevalence. Further investigations are warranted to better understand mechanisms underlying asthma increase or stagnation.

Can multiple doses of BCG vaccine protect against asthma?

OBJECTIVE

To compare BCG vaccination involving a single intradermal dose and that involving multiple doses, one given with the multiple puncture technique, in terms of the protective effect against the subsequent onset of asthma.

METHODS

A retrospective cohort study involving 2,311 individuals having received the BCG vaccine. The patients were classified according to the number of doses of BCG vaccine administered (one; two; or three or more). The minimum follow-up period in order to determine whether there was any protective effect of BCG vaccination regarding the diagnosis of asthma was 10 years.

RESULTS

The sample included 1,317 individuals (56.99%) who had received only one BCG dose, 644 (27.87%) who had received two doses, and 350 (15.14%) who had received three or more doses. The number of patients diagnosed with asthma among those who had received one dose, two doses and three or more doses was, respectively, 216 (16.40%), 107 (16.61%) and 50 (14.28%). There were no significant differences among the groups.

CONCLUSIONS

In the study sample, the prevalence of asthma among individuals having received multiple doses of the BCG vaccine was no different than that observed among those having received a single dose.

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.

Update on vaccination guidelines for allergic children

Children with allergic or atopic diseases require immunization just like non-atopic children. However, vaccination of such children requires some special considerations and precautions. Children may be allergic to specific vaccine constituents such as gelatin or egg. Children who have suffered an apparent allergic reaction to a vaccine should be evaluated by an allergist to determine the culprit allergen and to make recommendations regarding future vaccination. In rare circumstances, certain vaccines may cause acute exacerbations of allergic diseases, but the contention that vaccination causes allergic disease is not substantiated by any available evidence.

Which population level environmental factors are associated with asthma, rhinoconjunctivitis and eczema? Review of the ecological analyses of ISAAC Phase One

The International Study of Asthma and Allergies in Childhood (ISAAC) Phase One showed large worldwide variations in the prevalence of symptoms of asthma, rhinoconjunctivitis and eczema, up to 10 to 20 fold between countries. Ecological analyses were undertaken with ISAAC Phase One data to explore factors that may have contributed to these variations, and are summarised and reviewed here.In ISAAC Phase One the prevalence of symptoms in the past 12 months of asthma, rhinoconjunctivitis and eczema were estimated from studies in 463,801 children aged 13 - 14 years in 155 centres in 56 countries, and in 257,800 children aged 6-7 years in 91 centres in 38 countries. Ecological analyses were undertaken between symptom prevalence and the following: Gross National Product per capita (GNP), food intake, immunisation rates, tuberculosis notifications, climatic factors, tobacco consumption, pollen, antibiotic sales, paracetamol sales, and outdoor air pollution.Symptom prevalence of all three conditions was positively associated with GNP, trans fatty acids, paracetamol, and women smoking, and inversely associated with food of plant origin, pollen, immunisations, tuberculosis notifications, air pollution, and men smoking. The magnitude of these associations was small, but consistent in direction between conditions. There were mixed associations of climate and antibiotic sales with symptom prevalence.The potential causality of these associations warrant further investigation. Factors which prevent the development of these conditions, or where there is an absence of a positive correlation at a population level may be as important from the policy viewpoint as a focus on the positive risk factors. Interventions based on small associations may have the potential for a large public health benefit.

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.

Decreased risk for atopic disorder associated with highly hyperreactive tuberculin skin test reaction in children and adolescents

BACKGROUND

It is speculated that the exposure to Mycobacterium tuberculosis, either by infection or by Bacillus Calmette-Guérin vaccination, may inhibit the onset of atopy by the modification of immune profiles leading to a shift of T(H)1/T(H)2 balance to the T(H)1 side.

OBJECTIVE

One hundred eighty-six patients hyperreactive at tuberculin skin test (TST) were examined in order to investigate the prevalence of atopic disorder, particularly referring to the association between the size of the TST induration and the prevalence of sensitization and manifest atopic disorder.

METHODS

The study consisted of a family history record, patients' medical history assessment and clinical examination, skin prick test (SPT), serum total and allergen-specific IgE (sIgE) measurement and eosinophil count.

RESULTS

Atopic disorder was present in 49 (26.3%) patients tested. No significant difference between the groups based on the TST induration size (15-24 mm vs. > or =25 mm) was found for gender distribution, family atopy history, total IgE measurement, eosinophil count, positive SPT, and the presence of sIgE. A significant difference was found for the age median (14.0 years vs. 13.0 years), childhood atopy record, and manifest atopic disorder. No association between the size of the TST induration and the incidence of allergic sensitization was demonstrated. However, a significant inverse association between the size of the TST induration and manifest atopic disorder was demonstrated.

CONCLUSION

In patients highly hyperreactive at TST, the size of the induration is inversely associated with manifest atopic disorder.

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.

Early atopic disease and early childhood immunization--is there a link?

BACKGROUND

There are frequent concerns about early immunizations among the parents of children at heightened risk for atopy. The study assessed the effect of vaccine immunization before the first birthday on eczema severity and allergic sensitization in the second year of life.

METHODS

A total of 2184 infants, aged 1-2 years, with established atopic dermatitis and a family history of allergy, from 97 study centres in 10 European countries, South Africa and Australia were included. Exposure to vaccines (diphtheria, tetanus, pertussis, polio, Haemophilus influenzae Type B, hepatitis B, mumps, measles, rubella, varicella, BCG, meningococci and pneumococci) and immunization dates were recorded from immunization cards. Immunoglobulin E (IgE) was determined by RAST and eczema severity was assessed by scoring atopic dermatitis (SCORAD).

RESULTS

Immunization against any target was not associated with an increased risk of allergic sensitization to food or inhalant allergens. Varicella immunization (only 0.7% immunized) was inversely associated with total IgE > 30 kU/l (OR 0.27; 95% CI 0.08-0.87) and eczema severity (OR 0.34; 95% CI 0.12-0.93). Pertussis immunization (only 1.7% nonimmunized) was inversely associated with eczema severity (OR 0.30; 95% CI 0.10-0.89). Cumulative received vaccine doses were inversely associated with eczema severity (P = 0.0107). The immunization coverage of infants before and after the onset of atopic dermatitis was similar.

CONCLUSION

In children at heightened risk for atopy, common childhood immunization in the first year is not associated with an increased risk of more severe eczema or allergic sensitization. Parents of atopic children should be encouraged to fully immunize their children.

Potential health effects from non-specific stimulation of the immune function in early age: the example of BCG vaccination

There is increasing, but still inconsistent evidence that vaccinations and childhood infections may play a role in the normal maturation of the immune system, and in the development and balance of immune regulatory pathways, both of which might impact health later in life. This review covers the epidemiological evidence regarding the role of Bacillus Calmette-Guérin (BCG) vaccination on the following inflammatory or autoimmune diseases: asthma and allergic diseases, Crohn's disease (CD), insulin-dependent diabetes mellitus (IDDM), and specific cancers. The literature is more comprehensive for asthma and allergic diseases, with 16 studies reporting the absence of an association while seven rather suggest a protective effect of BCG. We found insufficient evidence on CD to conclude at this point. Overall, the evidence for IDDM based on four studies leans towards no association, although some effects were observed in population subsets. Five epidemiological investigations provide evidence on a possible link with cancer incidence or mortality at various sites, with indications of both increased and decreased risks. Given the potential public health implications, it is imperative to acquire a better understanding of how BCG vaccination could influence the development of such chronic health conditions in the population.

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.

Prevalence and associated factors of allergic rhinitis and atopic dermatitis in children

Allergic disorders are the chronic diseases of greatest pediatric morbidity, affecting over 25 % of the pediatric population. Indeed, this situation has been referred to as an "allergic epidemic". In comparison with asthma, atopic dermatitis and allergic rhinitis have been less extensively investigated, although this does not mean that they should be regarded as minor disorders but rather as alterations that affect the quality of life of the patients and their families, which generate considerable direct and indirect costs. Despite an important research effort, the reason for this allergic epidemic is not well known. These are multifactor disorders without a single causal agent, in which the most important component is the genetic predisposition of the patient (atopy), modulated by environmental factors, exposure to allergens, infections and irritants, among others. A confounding element is the fact that the concept of allergic diseases encompasses phenotypes of rhinitis, atopic dermatitis or asthma in which no IgE-mediated atopic mechanism is demonstrated, and which can manifest in a way similar to true allergic phenotypes. Differentiation between the two is difficult to establish on the basis of self-administered questionnaires alone, in the absence of a precise etiological diagnosis. The present article reviews the numerous factors suggested to be responsible for the increase in allergic diseases recorded in the last few decades, and for the differences in prevalence observed among centres. For most of these factors the results published in the literature are contradictory, in some cases due to a lack of control of the associated interacting or confounding factors. Consensus exists for only some of these causal factors, such as the established parallelism between the increase in allergic diseases and the reduction in infectious processes on one hand, and the increase in particles generated by diesel fuel combustion on the other. In addition, the implicated factors could act differently (and in some cases even antagonically) upon atopy and on the different disease phenotypes, thereby complicating the study of these interactions even further.

Delay in diphtheria, pertussis, tetanus vaccination is associated with a reduced risk of childhood asthma

BACKGROUND

Early childhood immunizations have been viewed as promoters of asthma development by stimulating a T(H)2-type immune response or decreasing microbial pressure, which shifts the balance between T(H)1 and T(H)2 immunity.

OBJECTIVE

Differing time schedules for childhood immunizations may explain the discrepant findings of an association with asthma reported in observational studies. This research was undertaken to determine whether timing of diphtheria, pertussis, tetanus (DPT) immunization has an effect on the development of childhood asthma by age 7 years.

METHODS

This was a retrospective longitudinal study of a cohort of children born in Manitoba in 1995. The complete immunization and health care records of cohort children from birth until age 7 years were available for analysis. The adjusted odds ratio for asthma at age 7 years according to timing of DPT immunization was computed from multivariable logistic regression.

RESULTS

Among 11, 531 children who received at least 4 doses of DPT, the risk of asthma was reduced to (1/2) in children whose first dose of DPT was delayed by more than 2 months. The likelihood of asthma in children with delays in all 3 doses was 0.39 (95% CI, 0.18-0.86).

CONCLUSION

We found a negative association between delay in administration of the first dose of whole-cell DPT immunization in childhood and the development of asthma; the association was greater with delays in all of the first 3 doses. The mechanism for this phenomenon requires further research.

Tuberculin reactivity and allergic disorders in schoolchildren, Okinawa, Japan

BACKGROUND

Bacillus Calmette-Guérin (BCG) vaccination triggers a T-helper type 1 response. Whether BCG vaccination and positive tuberculin reactivity are preventive against allergic disorders remains controversial.

OBJECTIVE

The current cross-sectional study investigated the relationship of BCG vaccination and tuberculin reactivity with the prevalence of allergic disorders using data from the Ryukyus Child Health Study (RYUCHS).

METHODS

Subjects were 5717 schoolchildren aged 8-11 years in Okinawa, Japan. The RYUCHS collected information on symptoms of allergic disorders and potential confounding factors. The outcomes were based on diagnostic criteria from the International Study of Asthma and Allergies in Childhood. Data on BCG vaccination and tuberculin tests were obtained from school records. Allowance was made for grade, sex, sibship size, smoking in the household, paternal and maternal history of asthma, atopic eczema, and allergic rhinitis, and paternal and maternal educational level.

RESULTS

No measurable relationship was found between BCG vaccination in infants and the prevalence of allergic disorders. Among 5567 BCG-vaccinated children, positive tuberculin reactivity (induration >/=10 mm) in the first grade was independently associated with a decreased prevalence of wheeze, asthma, and atopic eczema: the multivariate odds ratios for wheeze, asthma, and atopic eczema were 0.80 (95% confidence interval [CI], 0.67-0.94), 0.78 (95% CI, 0.64-0.95), and 0.77 (95% CI, 0.62-0.95), respectively. The inverse associations were more pronounced in children with a negative parental allergic history than in those with a positive parental allergic history. There was no significant relationship between tuberculin reactivity and allergic rhinoconjunctivitis.

CONCLUSIONS

The findings suggest that positive tuberculin reactivity may be inversely associated with the prevalence of wheeze, asthma, and atopic eczema, but not allergic rhinoconjunctivitis, especially among Japanese children without a parental allergic history.

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.

Association between children's household living conditions and eczema in the Polokwane area, South Africa

The aim of the study was to determine the 12-month prevalence of eczema symptoms (ES), the prevalence of ever having had eczema (EE), and potential risk factors among 6-7-year-old children within a 60km radius of Polokwane city centre, Limpopo Province, South Africa. This study applied the International Study of Asthma and Allergies in Childhood (ISAAC) Phase III protocol. It was conducted during August 2004 (winter) and February 2005 (summer). Among the 2437 participants, the 12-month prevalence of ES (17%) was much lower than the prevalence of EE (38%). The multivariate logistic regression model revealed that the likelihood of having ES was significantly increased by 43% in rural areas, and by 54% when exposed to environmental tobacco smoke (ETS) at home. The model also revealed that the likelihood of EE significantly increased with ETS exposure at home (37%), and by the use of coal, paraffin, gas and/or electricity for cooking (28%). Living in a formal house significantly decreased the likelihood of EE by 23%. Eczema appears to be a substantial public health problem in the Polokwane area. It is hoped that future studies will scrutinize these results in more detail, to inform and influence policy decisions, and form a basis for a health-promotion intervention in the community.

Adverse events following immunization: perception and evidence

PURPOSE OF REVIEW

The aim of this article is to highlight the evidence on new and ongoing vaccine safety concerns in the light of several vaccines recently licensed and others made available and recommended more widely.

RECENT FINDINGS

There is increasingly convincing epidemiologic and laboratory evidence against a causal relation of several alleged adverse events following immunization. The scientific framework to detect and investigate adverse events following immunization is increasingly robust.

SUMMARY

Currently available vaccines are safe in immunocompetent individuals and there is no evidence to deviate from current immunization schedules.

Worldwide trends in the prevalence of asthma symptoms: phase III of the International Study of Asthma and Allergies in Childhood (ISAAC)

BACKGROUND

Phase I of the International Study of Asthma and Allergies in Childhood (ISAAC) was designed to allow worldwide comparisons of the prevalence of asthma symptoms. In phase III the phase I survey was repeated in order to assess changes over time.

METHODS

The phase I survey was repeated after an interval of 5-10 years in 106 centres in 56 countries in children aged 13-14 years (n = 304,679) and in 66 centres in 37 countries in children aged 6-7 years (n = 193,404).

RESULTS

The mean symptom prevalence of current wheeze in the last 12 months changed slightly from 13.2% to 13.7% in the 13-14 year age group (mean increase of 0.06% per year) and from 11.1% to 11.6% in the 6-7 year age group (mean increase of 0.13% per year). There was also little change in the mean symptom prevalence of severe asthma or the symptom prevalence measured with the asthma video questionnaire. However, the time trends in asthma symptom prevalence showed different regional patterns. In Western Europe, current wheeze decreased by 0.07% per year in children aged 13-14 years but increased by 0.20% per year in children aged 6-7 years. The corresponding findings per year for the other regions in children aged 13-14 years and 6-7 years, respectively, were: Oceania (-0.39% and -0.21%); Latin America (+0.32% and +0.07%); Northern and Eastern Europe (+0.26% and +0.05%); Africa (+0.16% and +0.10%); North America (+0.12% and +0.32%); Eastern Mediterranean (-0.10% and +0.79%); Asia-Pacific (+0.07% and -0.06%); and the Indian subcontinent (+0.02% and +0.06%). There was a particularly marked reduction in current asthma symptom prevalence in English language countries (-0.51% and -0.09%). Similar patterns were observed for symptoms of severe asthma. However, the percentage of children reported to have had asthma at some time in their lives increased by 0.28% per year in the 13-14 year age group and by 0.18% per year in the 6-7 year age group.

CONCLUSIONS

These findings indicate that international differences in asthma symptom prevalence have reduced, particularly in the 13-14 year age group, with decreases in prevalence in English speaking countries and Western Europe and increases in prevalence in regions where prevalence was previously low. Although there was little change in the overall prevalence of current wheeze, the percentage of children reported to have had asthma increased significantly, possibly reflecting greater awareness of this condition and/or changes in diagnostic practice. The increases in asthma symptom prevalence in Africa, Latin America and parts of Asia indicate that the global burden of asthma is continuing to rise, but the global prevalence differences are lessening.

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.

Ecological association between childhood asthma and availability of indoor chlorinated swimming pools in Europe

BACKGROUND

It has been hypothesised that the rise in childhood asthma in the developed world could result at least in part from the increasing exposure of children to toxic chlorination products in the air of indoor swimming pools.

OBJECTIVES

Ecological study to evaluate whether this hypothesis can explain the geographical variation in the prevalence of asthma and other atopic diseases in Europe.

METHODS

The relationships between the prevalences of wheezing by written or video questionnaire, of ever asthma, hay fever, rhinitis, and atopic eczema as reported by the International Study of Asthma and Allergies in Childhood (ISAAC), and the number of indoor chlorinated swimming pools per inhabitant in the studied centres were examined. Associations with geoclimatic variables, the gross domestic product (GDP) per capita, and several other lifestyle indicators were also evaluated.

RESULTS

Among children aged 13-14 years, the prevalence of wheezing by written questionnaire, of wheezing by video questionnaire, and of ever asthma across Europe increased respectively by 3.39% (95% CI 1.96 to 4.81), 0.96% (95% CI 0.28 to 1.64), and 2.73% (95% CI 1.94 to 3.52), with an increase of one indoor chlorinated pool per 100 000 inhabitants. Similar increases were found when analysing separately centres in Western or Northern Europe and for ever asthma in Southern Europe. In children aged 6-7 years (33 centres), the prevalence of ever asthma also increased with swimming pool availability (1.47%; 95% CI 0.21 to 2.74). These consistent associations were not found with other atopic diseases and were independent of the influence of altitude, climate, and GDP per capita.

CONCLUSIONS

The prevalence of childhood asthma and availability of indoor swimming pools in Europe are linked through associations that are consistent with the hypothesis implicating pool chlorine in the rise of childhood asthma in industrialised countries.

Vaccines, antibiotics, and atopy

PURPOSE

Early exposure to vaccines and antibiotics may increase the risk of developing atopy by protecting against infectious agents and reducing duration and severity of infections (the hygiene hypothesis). It may also shift the developing immune system towards a more allergic response. We assess possible associations in young allergy clinic patients.

METHODS

We conducted a case-control study of 6- to 16-year-old new allergy clinic patients who were skin tested for inhalant allergens during 1987-2001 and enrolled in KPNW since birth (n = 1074). Atopic cases had positive tests for at least one inhalant allergen. Non-atopic controls had negative tests for all inhalant allergens. Using logistic regression analysis, we estimated atopy odds ratios for vaccine and antibiotic exposure variables and associations between vaccine and antibiotic exposures during the first 2 years of life and subsequent new allergy diagnoses.

RESULTS

Atopy was not significantly associated with numbers of vaccine and antigen doses, or number of different antigens during the first 2 years of life. Number of antibiotic prescriptions was negatively associated with atopy risk. Neither exposure was significantly associated with risk of new allergy diagnoses in atopic children.

CONCLUSIONS

Atopy development appears to be unrelated to early vaccine exposure. Frequency of antibiotic prescriptions during early life, a proxy for infection frequency, appears to protect against allergic sensitization. Neither vaccines nor antibiotics appear to induce subsequent allergic reactions in atopic children.

Is childhood immunisation associated with atopic disease from age 7 to 32 years?

BACKGROUND

There is ongoing conjecture over whether childhood immunisation leads to an increased risk of developing atopic diseases.

OBJECTIVE

To examine associations between childhood immunisation and the risk of atopic disease.

METHOD

Immunisation histories of 8443 Tasmanian children born in 1961 obtained from school medical records were linked to the Tasmanian Asthma Study. Associations between immunisation status and atopic diseases were examined while adjusting for possible confounders using multiple logistic regression.

RESULTS

Diphtheria immunisation was weakly associated with an increased risk of asthma by age 7 years (odds ratio (OR) 1.3, 95% confidence interval (CI) 1.1 to 1.7), but there was no evidence of any association for four other vaccinations studied. An increased risk of eczema by age 7 years was associated with immunisation against diphtheria (OR 1.5, 95% CI 1.1 to 2.1), tetanus (OR 1.5, 95% CI, 1.1 to 2.0), pertussis (OR 1.5, 95% CI 1.1 to 1.9) and polio (OR 1.4, 95% CI 1.0 to 1.9) but not small pox. Similar but slightly weaker patterns of association were observed between the risk of food allergies and immunisation against diphtheria (OR 1.5, 95% CI 1.0 to 2.1), pertussis (OR 1.4, 95% CI 1.1 to 1.9), polio (OR 1.4, 95% CI 1.00 to 2.1) and tetanus (OR 1.30 95% CI 0.99 to 1.70), but not with small pox. There was no evidence of associations between immunisation history and hay fever, or incidence of later-onset atopic outcomes.

CONCLUSIONS

The few effects seen in this study are small and age-dependent, and nearly all our findings support numerous previous studies of no effect of vaccines on asthma. Based on these findings, the fear of their child developing atopic disease should not deter parents from immunising their children, especially when weighed against the benefits.

Worldwide time trends in the prevalence of symptoms of asthma, allergic rhinoconjunctivitis, and eczema in childhood: ISAAC Phases One and Three repeat multicountry cross-sectional surveys

BACKGROUND

Data for trends in prevalence of asthma, allergic rhinoconjunctivitis, and eczema over time are scarce. We repeated the International Study of Asthma and Allergies in Childhood (ISAAC) at least 5 years after Phase One, to examine changes in the prevalence of symptoms of these disorders.

METHODS

For the ISAAC Phase Three study, between 2002 and 2003, we did a cross-sectional questionnaire survey of 193,404 children aged 6-7 years from 66 centres in 37 countries, and 304,679 children aged 13-14 years from 106 centres in 56 countries, chosen from a random sample of schools in a defined geographical area.

FINDINGS

Phase Three was completed a mean of 7 years after Phase One. Most centres showed a change in prevalence of 1 or more SE for at least one disorder, with increases being twice as common as decreases, and increases being more common in the 6-7 year age-group than in the 13-14 year age-group, and at most levels of mean prevalence. An exception was asthma symptoms in the older age-group, in which decreases were more common at high prevalence. For both age-groups, more centres showed increases in all three disorders more often than showing decreases, but most centres had mixed changes.

INTERPRETATION

The rise in prevalence of symptoms in many centres is concerning, but the absence of increases in prevalence of asthma symptoms for centres with existing high prevalence in the older age-group is reassuring. The divergent trends in prevalence of symptoms of allergic diseases form the basis for further research into the causes of such disorders.

Fever, use of antibiotics, and acute gastroenteritis during infancy as risk factors for the development of asthma in Korean school-age children

OBJECTIVE

The hygiene hypothesis postulates that infections early in life might influence the development of asthma later in childhood. However, this hypothesis is controversial. The objective of this study was to determine whether there is a relationship between infection-related risk factors during infancy and development of asthma later in childhood.

METHODS

Data were obtained by a nationwide, population-based, cross-sectional study of 26,400 children, 7 to 12 years of age. Parents completed a questionnaire on symptoms of and risk factors for asthma, including the number of fever episodes, acute gastroenteritis, use of antibiotics, and immunization during infancy. The presence of asthma was defined by parental report of "wheeze in the last 12 months" or "asthma ever." Data were analyzed by logistic regression analysis.

RESULTS

The occurrence of fever during infancy was weakly associated with the development of asthma (P < 0.05). A higher frequency of episodes of fever was associated with a higher risk of development of asthma. The relationship between antibiotic use during infancy and development of asthma was also significant (P < 0.0001). The adjusted odds ratios of childhood asthma increased in proportion to the number of antibiotic courses during infancy. A history of acute gastroenteritis during infancy increased the risk of developing asthma in later life (P < 0.001). In contrast, immunization in infancy was not related to development of asthma in childhood (P > 0.05).

CONCLUSIONS

These data suggest that the development of childhood asthma is associated with episodes of fever, antibiotic use, and acute gastroenteritis during infancy.

[Treatment of locally advanced prostate cancer]

The management of clinically locally advanced prostate carcinoma (cT3) remains a controversial issue. The clinical stage cT3 consists of a mixture of overstaged T2 carcinomas but also contains lymph node-positive cases. Treatment options consist of radical prostatectomy, external beam radiotherapy, hormonal deprivation (early or delayed) and the so-called watchful waiting. In many cases multimodal therapy is used. Radical prostatectomy in the clinical stage T3 can achieve acceptable tumour-specific survival rates if patients are well selected. In this way, tumour-specific survival rates can be reached for pT3 patients which closely approach those of pT2 cases. In lymph node-positive cases after radical prostatectomy adjuvant hormonal treatment can prolong survival, but not in lymph node-negative cases. A benefit of adjuvant radiotherapy after radical prostatectomy has not been proven. Although it can postpone or prevent biochemical recurrence, it does not prolong overall survival. Treatment of stage cT3 by external beam radiotherapy alone results in unfavourable tumour-specific survival rates. In these cases definite improvement can be achieved by adjuvant androgen deprivation with LHRH analogues. If in case of severe comorbidity or advanced age primary hormonal treatment is chosen, early vs deferred treatment seems to prolong survival marginally.

Ecological correlation among prevalence of asthma symptoms, rhinoconjunctivitis and atopic eczema with notifications of tuberculosis and measles in the Brazilian population

This study aims to assess the relationship among incidence of tuberculosis and measles, in the general population, within the year of birth and the prevalence of asthma, rhinoconjunctivitis and atopic eczema in teenagers from different Brazilian cities enrolled in the International Study of Asthma and Allergies in Childhood (ISAAC) phases I and III. Positive answers to the questions: 'Have you had wheezing or whistling in the chest in the past 12 months?', 'In the past 12 months, has this nose problem been accompanied by itchy-watery eyes?' and 'Has this itchy rash at any time affected any of the following places: the folds of the elbows, behind the knees, in front of the ankles, under the buttocks, or around the neck, ears or eyes?' identified the teenagers with asthma, rhinoconjunctivitis, and atopic eczema, respectively. The incidence of tuberculosis and measles, in the general population, observed in the year of birth of the enrolled teenagers (1981/82 and 1988/89) were obtained from governmental agencies: National Foundation of Health (FUNASA) and Brazilian Institute of Geography and Statistics (IBGE). They were compared with the prevalence of asthma, rhinoconjunctivitis and atopic eczema reported in both ISAAC phases I and III. Although we observed reduction of the incidence of tuberculosis and measles in the general population in all cities, the prevalence of asthma, rhinoconjunctivitis and atopic eczema remained stable in most of the centers. In Pernambuco and Paraná, there has been a significant increase in the prevalence of rhinoconjunctivitis. These data do not corroborate the findings of an inverse relationship between the prevalence of atopic diseases and the decreasing incidence of tuberculosis and measles.

Negative attitude of highly educated parents and health care workers towards future vaccinations in the Dutch childhood vaccination program

BACKGROUND

It is unknown whether further expansion of the Dutch childhood vaccination program with other vaccines will be accepted and whom should be targeted in educational strategies.

AIM

To determine attitudes of parents towards possible future vaccinations for their children and the behavioural determinants associated with a negative attitude.

DESIGN

Questionnaire study.

METHODS

Parents of children aged between 3 months and 5 years of day-care centres were asked to fill out a questionnaire. Determinants of a negative attitude to comply with possible future vaccinations against example diseases such as pneumonia or influenza, hepatitis B, TBC, smallpox and SARS were assessed using polytomous logistic regression analysis.

RESULTS

Of the 283 respondents, 123 (43%) reported a positive attitude towards all vaccinations, 129 (46%) reported to have a positive attitude to have their child vaccinated against some diseases and 31 (11%) had no intention to comply with any new vaccination. Determinants of a fully negative attitude were a high education of the parent (odds ratio [OR] 3.3, 95% confidence interval [95% CI]: 1.3-8.6), being a health care worker (OR 4.2, 95% CI: 1.4-12.6), absence of religion (OR 2.6, 95% CI: 1.0-6.7), perception of vaccine ineffectiveness (OR 6.9, 95% CI: 2.5-18.9) and the perception that vaccinations cause asthma or allergies (OR 82.4, 95% CI: 8.9-766.8).

CONCLUSION

Modifiable determinants for a negative attitude to comply with new vaccinations are mainly based on lack of specific knowledge. These barriers to vaccinations might be overcome by improving health education in the vaccination program, especially when targeted at educated parents and health care workers.

The influence of childhood infections and vaccination on the development of atopy: A systematic review of the direct epidemiological evidence

BACKGROUND

The 'hygiene hypothesis' has been used to justify a belief common among homeopaths, that the suppression of childhood infections and immunisation may lead to the development of chronic atopic diseases.

OBJECTIVES

To analyse the influence of childhood infections and immunisation on the development of atopy.

METHODS

Qualitative systematic review of direct epidemiological evidence (Medline 1993-2004) concerning the influence of childhood infections and immunisation on the development of atopy and discussion based on homeopathy.

CONCLUSIONS

(1) Childhood infections do not protect against atopy; on the contrary, they increase the risk of allergic diseases, in agreement to Hahnemann's observations, which included epidemic diseases among the factors capable of stimulating the development of chronic diseases. (2) Vaccination is not a risk factor for atopy, notwithstanding the allergenic effect of some vaccines.

BCG immunization at birth and atopic diseases in a homogeneous population of Spanish schoolchildren

BACKGROUND

The role of immunization with bacillus Calmette-Guérin (BCG) in the prevalence of asthma, hay fever and atopic dermatitis is not definitely established and seems to be influenced by ethnic background. The aim of this study was to analyze the relationship between this immunization and the prevalence of those diseases in a homogeneous population of Spanish schoolchildren.

METHODS

The International Study of Asthma and Allergies in Childhood (ISAAC) core and environmental questionnaires were used in four different centers of the Spanish North Atlantic coast. Bilbao, San Sebastián and Asturias have a universal BCG immunization policy during the first days of life, whereas La Coruña discontinued this practice in 1989. Except for this center, immunization coverage was above 90%. A random sample of schools of Asturias or all schools in the city district (rest of centers) with children 6 and 7 years old was surveyed.

RESULTS

The participation rate was above 70%. After excluding those children born outside Spain, the numbers were 6,762 immunized and 2,828 nonimmunized. After adjusting for gender, age, smoking habits of the father and mother, truck traffic near the household, older and younger siblings and having a cat or a dog during the first year of the child's life, the adjusted ORs of the BCG-immunized children suffering from asthma, hay fever and atopic dermatitis were respectively 0.87 (95% CI 0.76-1.00), 0.87 (0.75-1.01) and 0.89 (0.76-1.05).

CONCLUSIONS

BCG immunization offers a weak but significant protection against asthma and hay fever in Spanish schoolchildren.

Atopic dermatitis and the 'hygiene hypothesis': too clean to be true?

BACKGROUND

The so-called 'hygiene hypothesis' postulates an inverse relationship between atopic dermatitis (AD) and an environment that leads to increased pathogen exposure.

OBJECTIVES

We sought to systematically identify, summarize and critically appraise: (i) the epidemiological evidence to suggest that environmental exposures that lead to an increase in microbial burden reduce the risk of AD; (ii) whether any specific infections have been shown to reduce AD risk; (iii) whether there is a link between immunizations, use of antibiotics and AD risk; and (iv) to comment on the new therapeutic approaches in AD that have evolved out of the 'hygiene hypothesis'.

METHODS

We searched Medline from 1966 until August 2004 to identify relevant studies for inclusion. Differences in study design and populations did not allow formal meta-analysis. Studies were therefore described qualitatively.

RESULTS

We identified 64 studies that were relevant to our review, 27 (42%) of which were of prospective design. There was prospective evidence to support an inverse relationship between AD and endotoxins, early day care and animal exposure. Two well-designed cohort studies have found a positive association between infections in early life and AD, and measles vaccination and AD. Antibiotic use was consistently associated with an increase in AD risk even into the antenatal period, although a few studies did not reach conventional statistical significance. A few small randomized controlled trials have suggested that probiotics can reduce AD severity and that probiotics may also be able to prevent AD to some degree.

CONCLUSIONS

Although population-based studies have suggested a consistent inverse relationship between AD and increasing family size, this does not seem to be explained by a straightforward increased exposure to a single environmental pathogen. The effect seen with early day care, endotoxin and animal exposure may be due to a nonpathogenic microbial stimulus of a chronic or recurrent nature. This would also explain the risk increase associated with antibiotic use. Caution should prevail in the prescribing of antibiotics early in life, especially in children with a family history of AD. Larger well-designed pragmatic trials on probiotics and the prevention and treatment of AD are now needed to inform whether such interventions should be used in routine clinical practice.

Another explanation for the low allergy rate in the rural Alpine foothills

A low allergy rate in coal and wood heated homes has been described in the small villages in the Alpine foothills and subsequently found to be associated with the farming environment. This was interpreted within the framework of the hygiene hypothesis but there are also alternative explanations. Lower air pollution could be one reason, which is, however, unlikely since the differences between the Bavarian countryside and the Munich municipal area were only weak. There could be genetic differences between the urban and rural population by previous isolation or by self-selection. The potential drop-out of allergy genes, however, will also not explain the absent increase of allergies in two generations. More likely, other lifestyle factors are important. Dietary habits are different in farmers and a less frequent vitamin D supplementation of newborns (otherwise expected to be allergy promoting) has been shown recently. The underlying cause for the "non-allergic farm child" remains speculative until the transfer of any farm-associated factor is leading to a similar risk reduction in the general population.