Relationship between HLA genetic variations, COVID-19 vaccine antibody response, and risk of breakthrough outcomes

The rapid global distribution of COVID-19 vaccines, with over a billion doses administered, has been unprecedented. However, in comparison to most identified clinical determinants, the implications of individual genetic factors on antibody responses post-COVID-19 vaccination for breakthrough outcomes remain elusive. Here, we conducted a population-based study including 357,806 vaccinated participants with high-resolution HLA genotyping data, and a subset of 175,000 with antibody serology test results. We confirmed prior findings that single nucleotide polymorphisms associated with antibody response are predominantly located in the Major Histocompatibility Complex region, with the expansive HLA-DQB1*06 gene alleles linked to improved antibody responses. However, our results did not support the claim that this mutation alone can significantly reduce COVID-19 risk in the general population. In addition, we discovered and validated six HLA alleles (A*03:01, C*16:01, DQA1*01:02, DQA1*01:01, DRB3*01:01, and DPB1*10:01) that independently influence antibody responses and demonstrated a combined effect across HLA genes on the risk of breakthrough COVID-19 outcomes. Lastly, we estimated that COVID-19 vaccine-induced antibody positivity provides approximately 20% protection against infection and 50% protection against severity. These findings have immediate implications for functional studies on HLA molecules and can inform future personalised vaccination strategies.

Updated core competencies in pharmacoepidemiology to inform contemporary curricula and training for academia, government, and industry

PURPOSE

The first paper to specify the core content of pharmacoepidemiology as a profession was published by an ISPE (International Society for Pharmacoepidemiology) workgroup in 2012 (Jones JK et al. PDS 2012; 21[7]:677-689). Due to the broader and evolving scope of pharmacoepidemiology, ISPE considers it important to proactively identify, update and expand the list of core competencies to inform curricula of education programs; thus, better positioning pharmacoepidemiologists across academic, government (including regulatory), and industry positions. The aim of this project was to update the list of core competencies in pharmacoepidemiology.

METHODS

To ensure applicability of findings to multiple areas, a working group was established consisting of ISPE members with positions in academia, industry, government, and other settings. All competencies outlined by Jones et al. were extracted from the initial manuscript and presented to the working group for review. Expert-based judgments were collated and used to identify consensus. It was noted that some competencies could contribute to multiple groups and could be directly or indirectly related to a group.

RESULTS

Five core domains were proposed: (1) Epidemiology, (2) Clinical Pharmacology, (3) Regulatory Science, (4) Statistics and data science, and (5) Communication and other professional skills. In total, 55 individual competencies were proposed, of which 25 were new competencies. No competencies from the original work were dropped but aggregation or amendments were made where considered necessary.

CONCLUSIONS

While many core competencies in pharmacoepidemiology have remained the same over the past 10 years, there have also been several updates to reflect new and emerging concepts in the field.

Risk of Arterial and Venous Thrombotic Events Among Patients with COVID-19: A Multi-National Collaboration of Regulatory Agencies from Canada, Europe, and United States

Purpose

Few studies have examined how the absolute risk of thromboembolism with COVID-19 has evolved over time across different countries. Researchers from the European Medicines Agency, Health Canada, and the United States (US) Food and Drug Administration established a collaboration to evaluate the absolute risk of arterial (ATE) and venous thromboembolism (VTE) in the 90 days after diagnosis of COVID-19 in the ambulatory (eg, outpatient, emergency department, nursing facility) setting from seven countries across North America (Canada, US) and Europe (England, Germany, Italy, Netherlands, and Spain) within periods before and during COVID-19 vaccine availability.

Patients and Methods

We conducted cohort studies of patients initially diagnosed with COVID-19 in the ambulatory setting from the seven specified countries. Patients were followed for 90 days after COVID-19 diagnosis. The primary outcomes were ATE and VTE over 90 days from diagnosis date. We measured country-level estimates of 90-day absolute risk (with 95% confidence intervals) of ATE and VTE.

Results

The seven cohorts included 1,061,565 patients initially diagnosed with COVID-19 in the ambulatory setting before COVID-19 vaccines were available (through November 2020). The 90-day absolute risk of ATE during this period ranged from 0.11% (0.09-0.13%) in Canada to 1.01% (0.97-1.05%) in the US, and the 90-day absolute risk of VTE ranged from 0.23% (0.21-0.26%) in Canada to 0.84% (0.80-0.89%) in England. The seven cohorts included 3,544,062 patients with COVID-19 during vaccine availability (beginning December 2020). The 90-day absolute risk of ATE during this period ranged from 0.06% (0.06-0.07%) in England to 1.04% (1.01-1.06%) in the US, and the 90-day absolute risk of VTE ranged from 0.25% (0.24-0.26%) in England to 1.02% (0.99-1.04%) in the US.

Conclusion

There was heterogeneity by country in 90-day absolute risk of ATE and VTE after ambulatory COVID-19 diagnosis both before and during COVID-19 vaccine availability.

A feasibility assessment of real-world data capabilities for monitoring vaccine safety and effectiveness in China: Human papillomavirus vaccination in the Yinzhou district as a use case

BACKGROUND

Real-world data (RWD) are increasingly used to generate real-world evidence (RWE) of vaccine safety and effectiveness for regulatory purposes. Assessing feasibility of using RWD sources prior to implementing observational studies is recommended. As a use case, we described the process and findings of a feasibility assessment to identify reliable and relevant data sources for monitoring the safety and effectiveness of the AS04-HPV-16/18 human papillomavirus (HPV) vaccine in China.

METHODS

Iterative multi-step process: (1) targeted literature review and data source mapping; (2) expert opinion from national RWD experts; (3) survey to evaluate the identified data source operational infrastructure; and (4) continuous appraisal of published studies using the identified data source.

RESULTS

The Yinzhou Regional Health Information Platform (YRHIP) was identified as a data source of main interest, based on its large population coverage, high cervical cancer screening rates, and availability of adult electronic immunization records. Field meetings with national RWD experts confirmed its suitability for post-authorization vaccine studies. Survey results showed that exposure data and relevant safety and effectiveness endpoints were recorded and linkable at the individual level across the platform. Iterative appraisal of emerging evidence from the literature corroborated these findings.

CONCLUSIONS

This feasibility assessment indicates that the YRHIP has the capacity to capture demographic, exposure, outcome and other data required to generate RWE on HPV vaccine safety and effectiveness in China. Studies using the YRHIP to monitor the AS04-HPV-16/18 vaccine in routine use building on this feasibility assessment are ongoing.

Assessing heterogeneity of electronic health-care databases: A case study of background incidence rates of venous thromboembolism

PURPOSE

Heterogeneous results from multi-database studies have been observed, for example, in the context of generating background incidence rates (IRs) for adverse events of special interest for SARS-CoV-2 vaccines. In this study, we aimed to explore different between-database sources of heterogeneity influencing the estimated background IR of venous thromboembolism (VTE).

METHODS

Through forest plots and random-effects models, we performed a qualitative and quantitative assessment of heterogeneity of VTE background IR derived from 11 databases from 6 European countries, using age and gender stratified background IR for the years 2017-2019 estimated in two studies. Sensitivity analyses were performed to assess the impact of selection criteria on the variability of the reported IR.

RESULTS

A total of 54 257 284 subjects were included in this study. Age-gender pooled VTE IR varied from 5 to 421/100 000 person-years and IR increased with increasing age for both genders. Wide confidence intervals (CIs) demonstrated considerable within-data-source heterogeneity. Selecting databases with similar characteristics had only a minor impact on the variability as shown in forest plots and the magnitude of the I2 statistic, which remained large. Solely including databases with primary care and hospital data resulted in a noticeable decrease in heterogeneity.

CONCLUSIONS

Large variability in IR between data sources and within age group and gender strata warrants the need for stratification and limits the feasibility of a meaningful pooled estimate. A more detailed knowledge of the data characteristics, operationalisation of case definitions and cohort population might support an informed choice of the adequate databases to calculate reliable estimates.

MOnitoring human papillomavirus Vaccine effect on Infection and cErvical diseases (MOVIE): Protocol for a cohort study using electronic health records from Yinzhou, China

Cervical cancer is the fourth most common cancer in women, with a high disease burden worldwide. Human papillomavirus (HPV) vaccination reduces HPV-related infection and associated cervical lesions and cancers. Few studies have explored HPV vaccination impact in real-world settings in China. This study aims to monitor HPV vaccine uptake and its effects on HPV-related diseases, evaluating vaccine effectiveness in a real-world context and complementing clinical trial results. Electronic health records (EHRs) from 2010 to 2020 from the Yinzhou Regional Health Information Platform (YRHIP) will be queried/extracted to identify and monitor HPV vaccine uptake in females aged 9-45 years, and HPV-related screening and prevalence (i.e., cervical HPV infection, cervical intraepithelial neoplasia [CIN] grades 1-3, and cervical cancer) in a cohort of females aged 9-70 years. Cervical cancer screening guidelines and expert consultation will be used for intra-database validation, to determine the best algorithm for identifying HPV-related disease. Pre-launch (2010-2016) and post-launch (2018-2020) periods are predefined. A time trend analysis will be performed to describe the vaccination impact on disease prevalence and, if prerequisite conditions are met, vaccine effectiveness will be computed using logistic regression, adjusting for age, calendar year, history of screening and HPV infection. Cohort study design, outcomes validation, data linkage, and multi-step statistical analyses could provide valuable experience for designing other real-world studies in the future. The study outcomes can help inform policy-makers about uptake and HPV vaccination policy in girls and women in Yinzhou District, and provide insights on progress toward achieving goals set by the World Health Organization.

Comparative effectiveness of heterologous third dose vaccine schedules against severe covid-19 during omicron predominance in Nordic countries: population based cohort analyses

OBJECTIVE

To investigate the comparative vaccine effectiveness of heterologous booster schedules (ie, three vaccine doses) compared with primary schedules (two vaccine doses) and with homologous mRNA vaccine booster schedules (three vaccine doses) during a period of omicron predominance.

DESIGN

Population based cohort analyses.

SETTING

Denmark, Finland, Norway, and Sweden, 27 December 2020 to 31 December 2022.

PARTICIPANTS

All adults aged ≥18 years who had received at least a primary vaccination schedule of AZD1222 (Oxford-AstraZeneca) or monovalent SARS-CoV-2 wild type (ancestral) strain based mRNA vaccines BNT162b2 (Pfizer-BioNTech) or mRNA-1273 (Moderna), in any combination.

MAIN OUTCOME MEASURES

The main outcome measure was country combined risks of covid-19 related hospital admission and death with covid-19 and additional outcomes of covid-19 related admission to an intensive care unit and SARS-CoV-2 infection. During a period of omicron predominance, these outcomes were compared in those who received a heterologous booster versus primary schedule (matched analyses) and versus those who received a homologous mRNA vaccine booster (weighted analyses). Follow-up was for 75 days from day 14 after the booster dose; comparative vaccine effectiveness was calculated as 1-risk ratio.

RESULTS

Across the four Nordic countries, 1 086 418 participants had received a heterologous booster schedule of AZD1222+BNT162b2 or mRNA-1273 and 2 505 093 had received a heterologous booster schedule of BNT162b2+mRNA-1273. Compared with the primary schedule only (two doses), the vaccine effectiveness of heterologous booster schedules comprising AZD1222+BNT162b2 or mRNA-1273 and BNT162b2+mRNA-1273 was 82.7% (95% confidence interval 77.1% to 88.2%) and 81.5% (78.9% to 84.2%) for covid-19 related hospital admission and 95.9% (91.6% to 100.0%) and 87.5% (82.5% to 92.6%) for death with covid-19, respectively. Homologous mRNA booster schedules were similarly associated with increased protection against covid-19 related hospital admission (≥76.5%) and death with covid-19 (≥84.1%) compared with previous primary course vaccination only. When a heterologous booster schedule was compared with the homologous booster schedule, vaccine effectiveness was 27.2% (3.7% to 50.6%) for AZD1222+BNT162b2 or mRNA-1273 and 23.3% (15.8% to 30.8%) for BNT162b2+mRNA-1273 schedules against covid-19 related hospital admission and 21.7% (-8.3% to 51.7%) and 18.4% (-15.7% to 52.5%) against death with covid-19, respectively.

CONCLUSION

Heterologous booster schedules are associated with increased protection against severe, omicron related covid-19 outcomes compared with primary course schedules and homologous booster schedules.

Safety Monitoring of COVID-19 Vaccines: Perspective from the European Medicines Agency

Prior to deployment of coronavirus disease 2019 (COVID-19) vaccines in the European Union in 2021, a high vaccine uptake leading to an unprecedented volume of safety data from spontaneous reports and real-world evidence, was anticipated. The European Medicines Agency (EMA) implemented specific activities to ensure enhanced monitoring of emerging vaccine safety information, including intensive monitoring of reports of adverse events of special interest and the use of observed-to-expected analyses. The EMA also commissioned several independent observational studies using a large network of electronic healthcare databases and primary data collection via mobile and web-based applications. This preparedness was key for two high-profile safety signals: thrombosis with thrombocytopenia syndrome (TTS), a new clinical entity associated with adenovirus-vectored vaccines, and myocarditis/pericarditis with messenger RNA vaccines. With no existing case definition nor background rates, the signal of TTS posed particular challenges. Nevertheless, it was rapidly identified, evaluated, contextualized and the risk minimized thanks to close surveillance and an efficient use of available evidence, clinical expertise and flexible regulatory tools. The two signals illustrated the complementarity between spontaneous and real-world data, the former enabling rapid risk identification and communication, the latter enabling further characterization. The COVID-19 pandemic has tremendously enhanced the development of tools and methods to harness the unprecedented volume of safety data generated for the vaccines. Areas for further improvement include the need for better and harmonized data collection across Member States (e.g., stratified vaccine exposure) to support signal evaluation in all population groups, risk contextualization, and safety communication.

Comparative risk of thrombosis with thrombocytopenia syndrome or thromboembolic events associated with different covid-19 vaccines: international network cohort study from five European countries and the US

OBJECTIVE

To quantify the comparative risk of thrombosis with thrombocytopenia syndrome or thromboembolic events associated with use of adenovirus based covid-19 vaccines versus mRNA based covid-19 vaccines.

DESIGN

International network cohort study.

SETTING

Routinely collected health data from contributing datasets in France, Germany, the Netherlands, Spain, the UK, and the US.

PARTICIPANTS

Adults (age ≥18 years) registered at any contributing database and who received at least one dose of a covid-19 vaccine (ChAdOx1-S (Oxford-AstraZeneca), BNT162b2 (Pfizer-BioNTech), mRNA-1273 (Moderna), or Ad26.COV2.S (Janssen/Johnson & Johnson)), from December 2020 to mid-2021.

MAIN OUTCOME MEASURES

Thrombosis with thrombocytopenia syndrome or venous or arterial thromboembolic events within the 28 days after covid-19 vaccination. Incidence rate ratios were estimated after propensity scores matching and were calibrated using negative control outcomes. Estimates specific to the database were pooled by use of random effects meta-analyses.

RESULTS

Overall, 1 332 719 of 3 829 822 first dose ChAdOx1-S recipients were matched to 2 124 339 of 2 149 679 BNT162b2 recipients from Germany and the UK. Additionally, 762 517 of 772 678 people receiving Ad26.COV2.S were matched to 2 851 976 of 7 606 693 receiving BNT162b2 in Germany, Spain, and the US. All 628 164 Ad26.COV2.S recipients from the US were matched to 2 230 157 of 3 923 371 mRNA-1273 recipients. A total of 862 thrombocytopenia events were observed in the matched first dose ChAdOx1-S recipients from Germany and the UK, and 520 events after a first dose of BNT162b2. Comparing ChAdOx1-S with a first dose of BNT162b2 revealed an increased risk of thrombocytopenia (pooled calibrated incidence rate ratio 1.33 (95% confidence interval 1.18 to 1.50) and calibrated incidence rate difference of 1.18 (0.57 to 1.8) per 1000 person years). Additionally, a pooled calibrated incidence rate ratio of 2.26 (0.93 to 5.52) for venous thrombosis with thrombocytopenia syndrome was seen with Ad26.COV2.S compared with BNT162b2.

CONCLUSIONS

In this multinational study, a pooled 30% increased risk of thrombocytopenia after a first dose of the ChAdOx1-S vaccine was observed, as was a trend towards an increased risk of venous thrombosis with thrombocytopenia syndrome after Ad26.COV2.S compared with BNT162b2. Although rare, the observed risks after adenovirus based vaccines should be considered when planning further immunisation campaigns and future vaccine development.

Marketing Authorization Applications Made to the European Medicines Agency in 2018-2019: What was the Contribution of Real-World Evidence?

Information derived from routinely collected real‐world data has for a long time been used to support regulatory decision making on the safety of drugs and has more recently been used to support marketing authorization submissions to regulators. There is a lack of detailed information on the use and types of this real‐world evidence (RWE) as submitted to regulators. We used resources held by the European Medicines Agency (EMA) to describe the characteristics of RWE included in new marketing authorization applications (MAAs) and extensions of indication (EOIs) for already authorized products submitted to the EMA in 2018 and 2019. For MAAs, 63 of 158 products (39.9%) contained RWE with a total of 117 studies. For 31.7% of these products, the RWE submitted was derived from data collected before the planned authorization. The most common data sources were registries (60.3%) followed by hospital data (31.7%). RWE was mainly included to support safety (87.3%) and efficacy (49.2%) with cohort studies being the most frequently used study design (88.9%). For EOIs, 28 of 153 products (18.3%) contained RWE with a total of 36 studies. For 57.1% of these products, studies were conducted prior to the EOIs. RWE sources were mainly registries (35.6%) and hospital data (27.0%). RWE was typically used to support safety (82.1%) and efficacy (53.6%). Cohort studies were the most commonly used study design (87.6%). We conclude that there is widespread use of RWE to support evaluation of MAAs and EOIs submitted to the EMA and identify areas where further research is required.

A phase III randomized, open-label, non-inferiority clinical trial comparing liquid and lyophilized formulations of oral live attenuated human rotavirus vaccine (HRV) in Indian infants

The human rotavirus vaccine (HRV; Rotarix, GSK) is available as liquid (Liq) and lyophilized (Lyo) formulations, but only Lyo HRV is licensed in India. In this phase III, randomized, open-label trial (NCT02141204), healthy Indian infants aged 6–10 weeks received 2 doses (1 month apart) of either Liq HRV or Lyo HRV. Non-inferiority of Liq HRV compared to Lyo HRV was assessed in terms of geometric mean concentrations (GMCs) of anti-RV immunoglobulin A (IgA), 1-month post-second dose (primary objective). Reactogenicity/safety were also evaluated. Seroconversion was defined as anti-RV IgA antibody concentration ≥20 units [U]/mL in initially seronegative infants (anti-RV IgA antibody concentration <20 U/mL) or ≥2-fold increase compared with pre-vaccination concentration in initially seropositive infants. Of the 451 enrolled infants, 381 (189 in Liq HRV and 192 in Lyo HRV group) were included in the per-protocol set. The GMC ratio (Liq HRV/Lyo HRV) was 0.93 (95% confidence interval [CI]: 0.65–1.34), with the lower limit of the 95% CI reaching ≥0.5, the pre-specified statistical margin for non-inferiority. In the Liq HRV and Lyo HRV groups, 42.9% and 44.3% (baseline) and 71.4% and 73.4% (1-month post-second dose) of infants had anti-RV IgA antibody concentration ≥20 U/mL, and overall seroconversion rates were 54.5% and 50.0%. Incidences of solicited and unsolicited adverse events were similar between groups and no vaccine-related serious adverse events were reported. Liq HRV was non-inferior to Lyo HRV in terms of antibody GMCs and showed similar reactogenicity/safety profiles, supporting the use of Liq HRV in Indian infants.

What is the context?

Rotavirus is the most common cause of acute gastronenteritis and contributes to the high number of hospitalizations and deaths in young children worldwide.

Vaccination against rotavirus has led to a significant decrease in rotavirus-related infections.

The human rotavirus vaccine Rotarix (GSK) is currently used as a liquid or lyophilized formulation.

In clinical trials conducted in European and North American infants, the liquid vaccine showed ability to induce immune response and safety comparable to the lyophilized formulation.

Only the lyophilized vaccine is currently marketed in india.

What is new?

We compared the 2-dose liquid and lyophilized human rotavirus vaccines in indian infants in a phase III clinical trial:

The ability to induce immune response for thw liquid formulation was not inferior to that observed for the lyophilized vaccine.

The safety profiles of the 2 formulations were comparable.

Why is this important?

This study shows that the liquid human rotavirus vaccine can be administrated to infants from india.

Effectiveness of "Priorix" Against Measles and Mumps Diseases in Children Born After 2004 in the United Kingdom: A Retrospective Case-control Study Using the Clinical Practice Research Datalink GOLD Database

BACKGROUND

Evidence on vaccine effectiveness (VE) may encourage vaccination and help fight the reemergence of measles and mumps in Europe. However, limited data exist on real-life effectiveness of individual measles, mumps and rubella (MMR) vaccines. This study evaluated VE of GSK's MMR vaccine ("Priorix") against measles and mumps.

METHODS

This retrospective, case-control study used UK data from the Clinical Practice Research Datalink GOLD linked to the Hospital Episode Statistics database to identify children 1-13 years old diagnosed with measles or mumps from January 2006 to December 2018. Cases were matched to controls according to birth month/year and practice region. Cases were identified using clinical codes (without laboratory confirmation). "Priorix" exposure was identified using vaccine batch identifiers. Children exposed to other MMR vaccines were excluded. Adjusted VE was estimated for ≥1 vaccine dose in all children, and for 1 dose and ≥2 doses in children ≥4 years at diagnosis.

RESULTS

Overall, 299 measles cases matched with 1196 controls (87.6% <4 years old), and 243 mumps cases matched with 970 controls (74.2% <4 years old) were considered. VE for ≥1 dose in all children was 78.0% (97.5% confidence interval: 67.2%-85.3%) for measles and 66.7% (48.1%-78.6%) for mumps. In children ≥4 years old, VE after 1 dose was 74.6% (-21.7% to 94.7%) for measles and 82.3% (32.7%-95.3%) for mumps, and VE after ≥2 doses was 94.4% (79.7%-98.5%) for measles and 86.5% (64.0%-94.9%) for mumps.

CONCLUSIONS

"Priorix" is effective in preventing measles and mumps in real-life settings.

Suitability of databases in the Asia-Pacific for collaborative monitoring of vaccine safety

INTRODUCTION

Information regarding availability of electronic healthcare databases in the Asia-Pacific region is critical for planning vaccine safety assessments particularly, as COVID-19 vaccines are introduced. This study aimed to identify data sources in the region, potentially suitable for vaccine safety surveillance. This manuscript is endorsed by the International Society for Pharmacoepidemiology (ISPE).

METHODS

Nineteen countries targeted for database reporting were identified using published country lists and review articles. Surveillance capacity was assessed using two surveys: a 9-item introductory survey and a 51-item full survey. Survey questions related to database characteristics, covariate and health outcome variables, vaccine exposure characteristics, access and governance, and dataset linkage capability. Other questions collated research/regulatory applications of the data and local publications detailing database use for research.

RESULTS

Eleven databases containing vaccine-specific information were identified across 8 countries. Databases were largely national in coverage (8/11, 73%), encompassed all ages (9/11, 82%) with population size from 1.4 to 52 million persons. Vaccine exposure information varied particularly for standardized vaccine codes (5/11, 46%), brand (7/11, 64%) and manufacturer (5/11, 46%). Outcome data were integrated with vaccine data in 6 (55%) databases and available via linkage in 5 (46%) databases. Data approval processes varied, impacting on timeliness of data access.

CONCLUSIONS

Variation in vaccine data availability, complexities in data access including, governance and data release approval procedures, together with requirement for data linkage for outcome information, all contribute to the challenges in building a distributed network for vaccine safety assessment in the Asia-Pacific and globally. Common data models (CDMs) may help expedite vaccine safety research across the region.

Association between rotavirus gastroenteritis and intussusception: suggested evidence from a retrospective study in claims databases in the United States

The etiology of intussusception (IS), a serious gastrointestinal obstruction, remains unclear. Limited evidence suggests a role for viral infection. We investigated the risk of IS after rotavirus gastroenteritis (RV GE) in the first year of life. In this retrospective, self-controlled case series (SCCS), we assessed the risk of IS after RV GE using data from United States administrative claims databases. Incidence rate ratios (IRR) of IS were calculated for the 7- and 21-day risk periods after RV GE (main analysis) or after fracture (sensitivity analysis). A total of 290,912,068 subjects were screened; 42 presented claims for RV GE and IS, and 66 for fracture and IS. The IRRs of IS after RV GE were 79.6 (95% confidence interval, CI: 38.6-164.4) and 25.5 (95% CI: 13.2-49.2) in the 7- and 21-day risk periods. The sensitivity analysis showed an association between IS and fracture for both periods, suggesting potential confounding. Post-hoc analyses did not confirm the association between fracture and IS but suggested a potential association between RV GE and IS. A temporal association between RV GE and IS was detected using claims databases. Due to some limitations of the data sources, this association should be further investigated.

Regulatory and health technology assessment advice on postlicensing and postlaunch evidence generation is a foundation for lifecycle data collection for medicines

The understanding of the benefit risk profile, and relative effectiveness of a new medicinal product, are initially established in a circumscribed patient population through clinical trials. There may be uncertainties associated with the new medicinal product that cannot be, or do not need to be resolved before launch. Postlicensing or postlaunch evidence generation (PLEG) is a term for evidence generated after the licensure or launch of a medicinal product to address these remaining uncertainties. PLEG is thus part of the continuum of evidence development for a medicinal product, complementing earlier evidence, facilitating further elucidation of a product's benefit/risk profile, value proposition, and/or exploring broader aspects of disease management and provision of healthcare. PLEG plays a role in regulatory decision making, not only in the European Union but also in other jurisdictions including the USA and Japan. PLEG is also relevant for downstream decision‐making by health technology assessment bodies and payers. PLEG comprises studies of different designs, based on data collected in observational or experimental settings. Experience to date in the European Union has indicated a need for improvements in PLEG. Improvements in design and research efficiency of PLEG could be addressed through more systematic pursuance of Scientific Advice on PLEG with single or multiple decision makers. To date, limited information has been available on the rationale, process or timing for seeking PLEG advice from regulators or health technology assessment bodies. This article sets out to address these issues and to encourage further uptake of PLEG advice.

Observational studies of non-specific effects of Diphtheria-Tetanus-Pertussis vaccines in low-income countries: Assessing the potential impact of study characteristics, bias and confounding through meta-regression

INTRODUCTION

It has been suggested that some vaccines have effects beyond protection against the diseases they target, called non-specific effects (NSEs). In 2016, a systematic review by Higgins et al., commissioned by the WHO Strategic Advisory Group of Experts (SAGE) on immunization, estimated the relative risk (RR) of all-cause mortality after whole-cell Diphtheria-Tetanus-Pertussis (DTwP) vaccination to be 1.38 (95% CI: 0.92-2.08), and described these potential NSEs as inconsistent. However, the selection of studies for meta-analysis, based on their proneness to bias and confounding, was debated.

OBJECTIVE

To identify study characteristics and postulated risks of bias and confounding that might have impacted the RR of all-cause mortality after DTwP vaccination in observational studies conducted in low-income countries.

METHODS

Based on methodological considerations on study design and analysis, we systematically assessed all 17 DTwP studies from the Higgins et al. review for risk of selection bias, exposure and outcome misclassification, confounding and differential co-interventions. We used meta-regression to assess the impact of study characteristics and the postulated risks of bias and confounding on the RR estimates, and looked for outlying and influential risk estimates. Permutation tests were performed to control for false-positive findings.

RESULTS

The overall RR of all-cause mortality after DTwP vaccination including all but one outlying and influential study was 1.32 (95% CI: 0.83-2.08). Based on uni-variable meta-regression, we found that study location (p = 0.01), studies using the landmark approach (p = 0.015) and studies at high risk of exposure misclassification (p = 0.036) were significantly associated with increased RR estimates whereas studies at high risk of selection bias (p = 0.059) showed borderline significance. The results further suggest these effect modifiers are clustered in studies conducted in West-Africa.

CONCLUSION

The increased RR of all-cause mortality after DTwP might be confined to West-African countries and/or certain postulated risks of bias might have inflated these RRs.

Incidence of Invasive Cervical Cancer and Direct Costs Associated with its Management in Italy

Aim and background

Cervical cancer is the second most common cancer in European women aged 15–44 years. The aim of this study was to estimate the direct cost of managing invasive cervical cancer in Italy.

Methods

Data from the Italian Network of Cancer Registries were used to estimate the annual number of new cervical cancer cases. To assess the management costs, a typical management pathway for each FIGO (Fédération Internationale de Gynécologie et d'Obstétrique) cervical cancer stage was derived from published guidelines. Data from the Modena Cancer Registry were used to estimate the proportion of patients by FIGO stage. This algorithm was combined with tariffs for outpatient and inpatient procedures to obtain a mean cost for each FIGO stage.

Results

An estimated 2,927 new cases of cervical cancer occurred in Italy in 2005 (crude incidence 9.7/100,000; world age-standardized incidence 6.0/100,000). The estimated numbers of new cases by FIGO stage were: FIGO I, 1,927; FIGO II, 556; FIGO III, 259; and FIGO IV, 185. Costs for the most frequent procedures were estimated as: € 6,041 for radical hysterectomy or other surgery; € 4,901 for radio-chemotherapy; € 1,588 for brachytherapy; and € 3,795 for palliative chemotherapy. Mean management costs for incident cases (including 10 years of follow-up) were estimated at: FIGO I, € 6,024; FIGO II, € 10,572; FIGO III, € 11,367; FIGO IV, € 8707; and € 5,854 for the terminal phase (1 month). The total direct management cost was estimated at € 28.3 million per year.

Conclusions

This is one of the first studies to estimate the direct cost of treating patients newly diagnosed with invasive cervical cancer in Italy. Although according to current management pathways real treatment costs are likely to be underestimated, this information is necessary to design evidence-based vaccination policies able to harmonize primary and secondary prevention of cervical cancer.

Challenges in conducting post-authorisation safety studies (PASS): A vaccine manufacturer's view

Post-authorisation safety studies (PASS) of vaccines assess or quantify the risk of adverse events following immunisation that were not identified or could not be estimated pre-licensure. The aim of this perspective paper is to describe the authors' experience in the design and conduct of twelve PASS that contributed to the evaluation of the benefit-risk of vaccines in real-world settings. We describe challenges and learnings from selected PASS of rotavirus, malaria, influenza, human papillomavirus and measles-mumps-rubella-varicella vaccines that assessed or identified potential or theoretical risks, which may lead to changes to risk management plans and/or to label updates. Study settings include the use of large healthcare databases and de novo data collection. PASS methodology is influenced by the background incidence of the outcome of interest, vaccine uptake, availability and quality of data sources, identification of the at-risk population and of suitable comparators, availability of validated case definitions, and the frequent need for case ascertainment in large databases. Challenges include the requirement for valid exposure and outcome data, identification of, and access to, adequate data sources, and mitigating limitations including bias and confounding. Assessing feasibility is becoming a key step to confirm that study objectives can be met in a timely manner. PASS provide critical information for regulators, public health agencies, vaccine manufacturers and ultimately, individuals. Collaborative approaches and synergistic efforts between vaccine manufacturers and key stakeholders, such as regulatory and public health agencies, are needed to facilitate access to data, and to drive optimal study design and implementation, with the aim of generating robust evidence.

Importance of feasibility assessments before implementing non-interventional pharmacoepidemiologic studies of vaccines: lessons learned and recommendations for future studies

Purpose

Investigational and marketed vaccines are increasingly evaluated, and manufacturers are required to put in place mechanisms to monitor long‐term benefit–risk profiles. However, generating such evidence in real‐world settings remains challenging, especially when rare adverse events are assessed. Planning of an appropriate study design is key to conducting a valid study. The aim of this paper is to illustrate how feasibility assessments support the generation of robust pharmacoepidemiological data.

Methods

Following an initiative launched by the International Society for Pharmacoepidemiology in May 2014, a working group including members of the private and public sectors, was formed to assess the value of conducting feasibility assessments as a necessary step before embarking on larger‐scale post‐licensure studies. Based on five real‐life examples of feasibility assessments, lessons learned and recommendations were issued by the working group to support scientific reasoning and decision making when designing pharmacoepidemiologic vaccine studies.

Results

The working group developed a toolbox to provide a pragmatic approach to conducting feasibility assessments. The toolbox contains two main components: the scientific feasibility and the operational feasibility. Both components comprise a series of specific questions aimed at overcoming methodological and operational challenges.

Conclusions

A feasibility assessment should be formalized as a necessary step prior to the actual start of any pharmacoepidemiologic study. It should remain a technical evaluation and not a hypothesis testing. The feasibility assessment report may facilitate communication with regulatory agencies toward improving the quality of study protocols and supporting the endorsement of study objectives and methods addressing regulatory commitments. © 2016 The Authors. Pharmacoepidemiology and Drug Safety published by John Wiley & Sons Ltd.

Application of Probabilistic Multiple-Bias Analyses to a Cohort- and a Case-Control Study on the Association between Pandemrix™ and Narcolepsy

Background

An increase in narcolepsy cases was observed in Finland and Sweden towards the end of the 2009 H1N1 influenza pandemic. Preliminary observational studies suggested a temporal link with the pandemic influenza vaccine Pandemrix™, leading to a number of additional studies across Europe. Given the public health urgency, these studies used readily available retrospective data from various sources. The potential for bias in such settings was generally acknowledged. Although generally advocated by key opinion leaders and international health authorities, no systematic quantitative assessment of the potential joint impact of biases was undertaken in any of these studies.

Methods

We applied bias-level multiple-bias analyses to two of the published narcolepsy studies: a pediatric cohort study from Finland and a case-control study from France. In particular, we developed Monte Carlo simulation models to evaluate a potential cascade of biases, including confounding by age, by indication and by natural H1N1 infection, selection bias, disease- and exposure misclassification. All bias parameters were evidence-based to the extent possible.

Results

Given the assumptions used for confounding, selection bias and misclassification, the Finnish rate ratio of 13.78 (95% CI: 5.72–28.11) reduced to a median value of 6.06 (2.5^th- 97.5^th percentile: 2.49–15.1) and the French odds ratio of 5.43 (95% CI: 2.6–10.08) to 1.85 (2.5^th—97.5^th percentile: 0.85–4.08).

Conclusion

We illustrate multiple-bias analyses using two studies on the Pandemrix^™-narcolepsy association and advocate their use to better understand the robustness of study findings. Based on our multiple-bias models, the observed Pandemrix^™-narcolepsy association consistently persists in the Finnish study. For the French study, the results of our multiple-bias models were inconclusive.

Effect of the adjuvanted (AS03) A/H1N1 2009 pandemic influenza vaccine on the risk of rejection in solid organ transplant recipients in England: a self-controlled case series

OBJECTIVE

To assess the risk of solid organ transplant (SOT) rejection after vaccination with the adjuvanted (AS03) A/H1N1 2009 pandemic influenza vaccine Pandemrix.

DESIGN

Self-controlled case series (SCCS) in the UK Clinical Practice Research Datalink (CPRD) and its linked component of the Hospital Episodes Statistics (HES) inpatient database. Analyses were conducted using the SCCS method for censored, perturbed or curtailed post-event exposure.

PARTICIPANTS

Of the 184 transplant recipients having experienced at least one SOT rejection (liver, kidney, lung, heart or pancreas) during the study period from 1 October 2009 to 31 October 2010, 91 participants were included in the main analysis, of which 71 had been exposed to Pandemrix.

MAIN OUTCOME MEASURES

Occurrence of SOT rejection during risk (30 and 60 days after any Pandemrix dose) and control periods. Covariates in the CPRD included time since transplantation, seasonal influenza vaccination, bacterial and viral infections, previous SOT rejections and malignancies.

RESULTS

The relative incidence (RI) of rejection of any one of the five transplanted organs, adjusted for time since transplantation, was 1.05 (95% CI 0.52 to 2.14) and 0.80 (95% CI 0.42 to 1.50) within 30 and 60 days after vaccination, respectively. Similar estimates were observed for rejection of a kidney only, the most commonly transplanted organ (RI within 30 days after vaccination: 0.85 (95% CI 0.38 to 1.90)). Across various models and sensitivity analyses, RI estimates remained stable and within a consistent range around 1.0.

CONCLUSIONS

These results suggest a reassuring safety profile for Pandemrix with regard to the risk of rejection in SOT recipients in England and contribute to inform the benefit-risk of AS03-adjuvanted pandemic influenza vaccines in transplanted patients in the event of future pandemics.

TRIAL REGISTRATION NUMBER

NCT01715792.

Pandemrix™ and narcolepsy: A critical appraisal of the observational studies

A link between Pandemrix™ (AS03-adjuvanted H1N1 pandemic influenza vaccine, GSK Vaccines, Belgium) and narcolepsy was first suspected in 2010 in Sweden and Finland following a number of reports in children and adolescents. Initial scepticism about the reported association faded as additional countries reported similar findings, leading several regulatory authorities to restrict the use of Pandemrix™. The authors acknowledge that currently available data suggest an increased risk of narcolepsy following vaccination with Pandemrix™; however, from an epidemiologist's perspective, significant methodological limitations of the studies have not been fully addressed and raise questions about the reported risk estimates. We review the most important biases and confounders that potentially occurred in 12 European studies of the observed association between Pandemrix™ and narcolepsy, and call for further analyses and debate.

Safety of AS03-adjuvanted inactivated split virion A(H1N1)pdm09 and H5N1 influenza virus vaccines administered to adults: pooled analysis of 28 clinical trials

Clinical trials have shown that AS03-adjuvanted H5N1 and A(H1N1)pdm09 vaccines are highly immunogenic, although with an increased reactogenicity profile relative to non-adjuvanted vaccines in terms of the incidence of common injection site and systemic adverse events (AEs). We evaluated pooled safety data from 22,521 adults who had received an AS03-adjuvanted H5N1 or A(H1N1)pdm09 influenza or control vaccine with the purpose to identify medically-attended AEs (MAEs), including subsets of serious AEs (SAEs), potentially immune-mediated diseases (pIMDs), and AEs of special interest (AESI), and to explore a potential association of these AEs with the administration of an AS03-adjuvanted influenza vaccine. For participants who had received an AS03-adjuvanted vaccine, the relative risks (RRs) for experiencing a MAE or a SAE compared to control group (participants who had received a non-adjuvanted vaccine or saline placebo) were 1.0 (95% confidence interval [CI]: 0.9; 1.1) and 1.1 (95% CI: 0.9; 1.4), respectively. The overall RRs for experiencing an AESI or a pIMD (AS03-adjuvanted vaccine/control) were 1.2 (95% CI: 0.9; 1.6) and 1.7 (95% CI: 0.8; 3.8), respectively. Thirty-8 participants in the AS03-adjuvanted vaccine group had a pIMD reported after vaccine administration, yielding an incidence rate (IR) of 351.9 (95% CI: 249.1; 483.1) per 100,000 person-years. The estimated IRs in the AS03-adjuvanted vaccine group were greater than the literature reported rates for: facial paresis/VIIth nerve paralysis, celiac disease, thrombocytopenia and ulcerative colitis. These results do not support an association between AS03-adjuvanted H5N1 and A(H1N1)pdm09 vaccines and the AEs collected in the trials included in the analysis.

Acute Exacerbation and Respiratory InfectionS in COPD (AERIS): protocol for a prospective, observational cohort study

INTRODUCTION

The aetiology of acute exacerbations of chronic obstructive pulmonary disease (COPD) remains incompletely understood and strategies for treatment and prevention have not altered significantly for many years. Improved understanding of the role of respiratory pathogens in acute exacerbations of COPD (AECOPD) is required and the use of molecular microbiological techniques may lead to insights into host-pathogen interactions and the development of more targeted therapeutic approaches.

METHODS AND ANALYSES

Acute Exacerbation and Respiratory InfectionS in COPD (AERIS) is a longitudinal epidemiological study to assess how changes in the COPD airway microbiome contribute to the incidence and severity of AECOPD. Patients with COPD aged 40-85 are followed monthly for 2 years, and reviewed within 72 h of onset of symptoms of AECOPD. Exacerbations are detected using daily electronic diary cards. Blood, sputum, nasopharyngeal and urine samples are collected at prespecified timepoints. Molecular diagnostic and typing techniques are used to describe the dynamics of airway infection during AECOPD and stable disease, and associations with clinical outcome. This study aims to refine the case definition of AECOPD to reflect the possible microbiological aetiology. AERIS will assess the impact of AECOPD on health-related quality of life and healthcare resource utilisation, and the possible interactions between nutritional status, infection and immune responses.

ETHICS AND DISSEMINATION

AERIS is conducted in accordance with the Declaration of Helsinki and Good Clinical Practice, and has been approved by the institutional ethics and review board. All participants must provide written informed consent. The results obtained will be disseminated at international medical conferences and in peer-reviewed publications.

DISCUSSION

Few other studies have addressed the complexity of the microbiological and systemic components of COPD or employed real-time electronic tracking of symptoms to identify AECOPD and potential aetiological triggers.

RESULTS

Results of AERIS will increase our understanding of the contribution of pathogens to AECOPD, potentially leading to new targeted therapeutic and preventative interventions.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT01360398.

Impact of human papillomavirus-related genital diseases on quality of life and psychosocial wellbeing: results of an observational, health-related quality of life study in the UK

BACKGROUND

Data on the psychosocial burden of human papillomavirus (HPV)-related diseases other than cervical cancer are scarce. The objectives of this study were to measure and compare the psychosocial burden and the impact on health-related quality of life (HRQoL) of HPV-related lower genital tract diseases and genital warts (GW) using several generic and disease-specific instruments.

METHODS

Overall, 842 individuals with normal cervical cytology (n = 241), borderline nuclear abnormalities and/or mild dyskaryosis (n = 23), cervical intraepithelial neoplasia (CIN)1 (n = 84), CIN2/3 (n = 203), vulval intraepithelial neoplasia (VIN)2/3 (n = 43), GW (n = 186) and a history of GW (non-current) (n = 62) were included. The generic European Quality of Life Index Version 5D (EQ-5D) questionnaire was completed by patients with GW and VIN2/3. Sexual functioning was evaluated using the Change in Sexual Functioning Questionnaire (CSFQ). Psychosocial impact was measured in women using the HPV Impact Profile (HIP) questionnaire. HRQoL was assessed using a GW-specific questionnaire, the Cuestionario Especifico en Condilomas Acuminados (CECA) (completed by patients with GW and history of GW). For each instrument, scores were compared between groups using the Student's t-test. In addition, utility loss due to GW and VIN2/3 was evaluated by comparing mean EQ-5D scores weighted by age and sex with the UK general population normal values.

RESULTS

A significant psychosocial impact was found in women diagnosed with HPV-related genital diseases, particularly in those with GW. The health state of younger adults with GW was significantly impaired compared with UK normal values (mean EQ-5D index score 0.86 vs 0.94, p < 0.001 for 18-24-year-olds; 0.87 vs 0.93, p = 0.030 for 25-34-year-olds). VIN2/3 was found to have a significant negative impact on sexual functioning, and women with VIN2/3 had a highly impaired health state compared with women in the UK general population (weighted mean EQ-5D index score 0.72 vs 0.89, p < 0.001; weighted mean Visual Analogue Scale score 62 vs 85, p < 0.001).

CONCLUSIONS

HPV-related lower genital tract lesions and GW significantly impair psychosocial wellbeing and HRQoL. The psychosocial aspects of HPV-related diseases need to be considered when evaluating the potential benefit of HPV vaccination.

Meta-analysis of epidemiologic studies on cigarette smoking and liver cancer

BACKGROUND

Whereas the International Agency for Research on Cancer (IARC) Monograph concluded that the evidence for the relationship between cigarette smoking and liver cancer is sufficient, the US Surgeon General's report summarized the data as suggestive but not sufficient.

METHODS

A meta-analysis of previous epidemiologic studies may help to clarify the potential association. We identified 38 cohort studies and 58 case-control studies in a systematic literature search for studies on liver cancer and cigarette smoking. The meta-relative risk (mRR) of liver cancer and dose-response trends were calculated. Tests for heterogeneity, publication bias assessment and influence analyses were performed.

RESULTS

Compared with never smokers, the adjusted mRR was 1.51 [95% confidence interval (CI) 1.37-1.67] for current smokers and 1.12 (95% CI 0.78-1.60) for former smokers. The increased liver cancer risk among current smokers appeared to be consistent in strata of different regions, study designs, study sample sizes and publication periods.

CONCLUSION

The results of our meta-analysis show that tobacco smoking is associated with liver cancer development, which supports the conclusion by the IARC Monograph. This conclusion has an important public health message for areas with high smoking prevalence and high liver cancer incidence such as China.

Epidemiology and cost of treatment of genital warts in Spain

BACKGROUND

Genital warts (GW) are common and increasing in young people. Ninety percent of GW are due to Human Papillomavirus (HPV) types 6 and 11. The objective of this study was to assess the epidemiology and management costs associated with GW in Spain.

METHODS

A 1-year (2005) retrospective observational study was performed among a sample of gynaecologists, dermatologists and urologists in six autonomous regions in Spain. Men and women with newly diagnosed, recurrent or resistant GW were included. We estimated the incidence (new and recurrent cases) and prevalence (also including resistant cases) of GW. Healthcare resource use were collected and combined with unit costs to assess the mean cost of GW management per patient. These figures were extrapolated to the 14- to 64-year-old Spanish population to estimate the total cost of GW management from the Third Party Payer (TPP) and societal perspectives.

RESULTS

The overall annual incidence of GW was estimated at 160.4 cases per 100,000. Overall prevalence was calculated as 182.1 cases per 100,000, corresponding to 56 446 GW cases annually (14- to 64-year-old population). The mean management cost was 833 euros and 1056 euro per patient from the TPP and societal perspective, respectively. The overall annual cost was estimated at 47 million euros and 59.6 million euros, from the TPP and societal perspective, respectively.

CONCLUSION

This study provides a first overview of the burden of GW in Spain. A quadrivalent HPV vaccine that prevents HPV 6, 11, 16, 18 related diseases will have the potential to significantly decrease the socio-economic burden associated with GW in Spain.

Treatment patterns and associated costs for genital warts in Italy

OBJECTIVE

Genital warts are caused by human papillomavirus (HPV), principally types 6 and 11, and are highly contagious. This study assessed treatment patterns and costs of management of genital warts in Italy.

RESEARCH DESIGN AND METHODS

This was a retrospective, observational study conducted among gynaecologists, dermatologists, and specialists at sexually transmitted disease clinics in Italy. Resource-use data related to genital warts were collected for patients at risk in the age range 14-64 years examined during 2005. Unit costs were assigned to resource use to provide estimates of the direct, indirect and total costs per case of genital warts.

RESULTS

Twenty-eight investigators enrolled 341 patients aged 15-64 years, including 194 (56.9%), 81 (23.7%) and 66 (19.4%) patients with newly diagnosed, recurrent and resistant genital warts, respectively. Most patients (333/341; 97.7%) had at least one outpatient visit, while 43 (12.6%) patients were hospitalised, including 39 patients without an overnight stay (day-hospital cases, 11.4%). Self-applied medication was prescribed for 124 (36.4%) patients. Most outpatient cases (267/333; 80.2%) underwent an office-based procedure. Mean annual direct medical costs per patient, which were funded predominantly by the Italian National Health Service (there was some patient co-payment), were €242 for men and €332 for women. When productivity losses were included, mean total annual costs were €325 for men and €464 for women.

CONCLUSIONS

This is the first study of treatment patterns and costs for genital warts in Italy. Treatment patterns differ in some respects from those observed in other European countries, but costs generally appear similar. Despite the limitations of physician selection bias and over-representation of North Italy in the patient sample, the findings of this study may be useful in estimating the cost-effectiveness of introducing a quadrivalent HPV vaccination programme in Italy.

Farm exposure in utero may protect against asthma, hay fever and eczema

The aim of the present study was to assess which factors contribute to the lower prevalence of allergic diseases in farmers' children, and the importance of timing of exposure. In a cross-sectional questionnaire survey, asthma symptoms, hay fever and eczema were assessed, as well as current, early and prenatal farm-related exposures in 1,333 farmers' children and 566 reference children aged 5-17 yrs. Farmers' children had a lower incidence of asthma symptoms and eczema. Current and maternal exposure during pregnancy to animals and/or grain and hay reduced the risk of asthma symptoms, hay fever and eczema. The exposure-response association for maternal exposure was nonlinear for most outcomes. After mutual adjustment, the effects of prenatal exposure remained unchanged whereas current exposure remained protective only for asthma medication, asthma ever and hay fever. Exposure during the first 2 yrs was not associated with symptoms, after controlling for prenatal exposure. A combination of prenatal and current exposure was most strongly associated with wheeze (odds ratio (OR) 0.48, 95% confidence interval (CI) 0.28-0.80), asthma medication (OR 0.50, 95% CI 0.30-0.82), asthma ever (OR 0.50, 95% CI 0.33-0.76), hay fever (OR 0.47, 95% CI 0.30-0.73) and eczema (OR 0.46, 95% CI 0.30-0.70). Prenatal exposure may contribute to the low prevalence of asthma, hay fever and eczema in farmers' children, but continued exposure may be required to maintain optimal protection.

[From genomics to surveillance, prevention and control: new challenges for the African meningitis belt]

An international conference was held in Niamey, Niger, in November 2005. It aimed at reviewing the current situation in the meningitis belt. This region stretches from Senegal to Ethiopia and is characterized by high levels of seasonal endemicity with large epidemics of meningococcal meningitis occurring cyclically, generally caused by N. meningiditis serogroup A. WHO currently recommends a reactive strategy based on rapid detection of epidemics, intervention with antibiotics to treat cases and mass vaccination with a meningococcal polysaccharide vaccine to halt the outbreak. Epidemiological patterns of the disease in Africa have been changing with the occurrence of outbreaks outside the meningitis belt and with the emergence of serogroup W135, which first caused an epidemic among Hajj pilgrims in 2000 and then a large-scale meningitis outbreak in Burkina Faso in 2002. Consequently enhanced laboratory surveillance and confirmation of the strain responsible for the outbreak are required. New rapid dipstick tests have been developed through a collaboration between Institut Pasteur and CERMES. They are designed for bedside diagnosis and detect meningococcal antigens present in CSF using immunochromatography. The treatment of meningococcal meningitis during epidemics is based on short-course, long-acting oily chloramphenicol. An alternative is the use of ceftriaxone, which is equally effective and can be used in pregnant women and infants. A low-cost, monovalent serogroup A meningococcal conjugate vaccine for large-scale use in Africa is under development. In spite of the emergence of W135 strains in the meningitis belt, N. meningiditis A continues to be the principal strain isolated during the epidemic seasons and elimination of outbreaks of N. meningiditis serogroup A can still be considered as the primary objective of a preventive vaccination strategy.

Distinct patterns of evolution between respiratory syncytial virus subgroups A and B from New Zealand isolates collected over thirty-seven years

Respiratory syncytial virus (RSV) is the most important cause of viral lower respiratory tract infections in infants and children worldwide. In New Zealand, infants with RSV disease are hospitalized at a higher rate than other industrialized countries, without a proportionate increase in known risk factors. The molecular epidemiology of RSV in New Zealand has never been described. Therefore, we analyzed viral attachment glycoprotein (G) gene sequences from 106 RSV subgroup A isolates collected in New Zealand between 1967 and 2003, and 38 subgroup B viruses collected between 1984 and 2004. Subgroup A and B sequences were aligned separately, and compared to sequences of viruses isolated from other countries during a similar period. Genotyping and clustering analyses showed RSV in New Zealand is similar and temporally related to viruses found in other countries. By quantifying temporal clustering, we found subgroup B viruses clustered more strongly than subgroup A viruses. RSV B sequences displayed more variability in stop codon usage and predicted protein length, and had a higher degree of predicted O-glycosylation site changes than RSV A. The mutation rate calculated for the RSV B G gene was significantly higher than for RSV A. Together, these data reveal that RSV subgroups exhibit different patterns of evolution, with subgroup B viruses evolving faster than A.

Infections, medication use, and the prevalence of symptoms of asthma, rhinitis, and eczema in childhood

BACKGROUND

The "hygiene hypothesis" postulates that infections during infancy may protect against asthma and atopy. There is also some evidence that antibiotic and/or paracetamol use may increase the risk of asthma.

METHODS

The study measured the association between infections, and medication use early in life and the risk of asthma at age 6-7 years. It involved 1584 children who had been notified to public health services with serious infections at age 0-4 years, and 2539 children sampled from the general population. For both groups, postal questionnaires were completed by parents.

RESULTS

There was little difference in the prevalence of current wheezing between the childhood infections group (prevalence = 23.5%) and the general population group (prevalence = 24.3%). There was also little difference whether the major site of infection was gastrointestinal (prevalence = 24.1%), invasive (prevalence = 24.6%) or respiratory (prevalence = 21.1%). However, in both groups, there were associations with antibiotic (OR = 1.78, 95% CI 1.49 to 2.14) or paracetamol (OR = 1.38, 95% CI 1.04 to 1.83) use in the first year of life or recent paracetamol use (OR = 2.10, 95% CI 1.78 to 2.49) and current wheezing. There was a weak protective effect of childhood infections in children who had not used antibiotics in the first year of life (OR = 0.78, 95% CI 0.55 to 1.10).

CONCLUSIONS

These findings are consistent with other evidence that antibiotic use early in life may increase the risk of asthma. They are also consistent with some preliminary evidence associating paracetamol use with an increased risk of asthma. Any protective effect of notifiable childhood infections was weak.

Exon 5 polymorphisms in the O6-alkylguanine DNA alkyltransferase gene and lung cancer risk in non-smokers exposed to second-hand smoke

PURPOSE

The objective of the study was to examine the association of three exon 5 variants in the O(6)-alkylguanine DNA alkyltransferase (AGT) gene involved in the repair of the mutagenic DNA lesion O(6)-alkylguanine formed by nitrosamines, with lung cancer risk in never-smokers.

EXPERIMENTAL DESIGN

Exon 5 of the AGT gene was sequenced in genomic DNA from 136 cases and 133 hospital- or population-based controls for whom questionnaire information on second-hand smoke and diet was available to determine the frequencies of the Gly(160)Arg, Ile(143)Val, and Lys(178)Arg variant alleles.

RESULTS

No codon (160)Arg variant alleles were found in the study population. The codon (143)Val and (178)Arg variant alleles, present at allele frequencies of 0.07, showed 100% linkage. The odds ratio (OR) of lung cancer for these variant carriers was 2.05 [95% confidence interval (CI) 1.03-4.07]. The risk varied between the different lung cancer pathologies with an increased risk for adenocarcinoma (OR 2.67, 95% CI 1.21-5.87) or small cell carcinoma (OR 4.83, 95% CI 0.91-25.7) but not for squamous cell carcinoma (OR 1.07, 95% CI 0.27-4.18). Compared with individuals carrying the mutant alleles unexposed to second-hand smoke, the OR for exposed variant carriers was 1.95 (95% CI 0.53-1.15); a similar interaction, although not significative, was observed for low consumption of cruciferous vegetables and for green vegetables and tomatoes.

CONCLUSIONS

These results point toward a role of AGT polymorphisms in lung cancer susceptibility among never-smokers, in particular among subjects exposed to environmental carcinogens.