Didier Giet

Immunogenicity Profile of a 3.75-μg Hemagglutinin Pandemic rH5N1 Split Virion AS03A-Adjuvanted Vaccine in Elderly Persons: A Randomized Trial

Background. Elderly persons often experience a reduced immune response to influenza vaccination. We evaluated the usual dose of AS03A-adjuvanted H5N1 pandemic vaccine (3.75 μg hemagglutinin of A/Vietnam/1194/2004-like strain) compared with a double dose in an elderly population. Methods. This phase 2, open-label study (NCT00397215; http://www.clinicaltrials.gov) randomized participants (age, ≥61 years) to receive, on days 0 and 21: (1) a single dose of AS03A-adjuvanted vaccine (n = 152), (2) a single dose of nonadjuvanted vaccine (n = 54), (3) a double dose of AS03A-adjuvanted vaccine (n = 145), or (4) a double dose of nonadjuvanted vaccine (n = 44). The primary end point was hemagglutination inhibition (HI) and neutralizing antibody response against vaccine antigen (according-to-protocol cohort). Results. Day 42 geometric mean titers for HI antibodies were 126.8 and 237.3 for single and double doses of the AS03A-adjuvanted vaccine, respectively. Corresponding values for neutralizing antibodies were 447.3 and 595.8. Although the immune response was higher with the double dose, European Committee for Human Medicinal Products criteria for seroconversion and seroprotection rates were achieved in both AS03A-adjuvanted groups. Antigen-specific CD4 T cell responses were elicited. Immune response persistence at 6 months was high. Immune response in the non-adjuvanted groups was considerably less. Conclusions. The AS03A-adjuvanted H5N1 vaccine can be administered elderly persons at the same dose and schedule as in younger adults.

Lifestyle Behaviours and Plasma Vitamin C and β-Carotene Levels from the ELAN Population (Liège, Belgium)

Several factors, including fruit and vegetables intakes, have been shown to significantly influence the plasma concentrations of the two antioxidants vitamin C and β-carotene. Deficiency levels of 6 mg/L (34.2 μM) for vitamin C and of 0.22 mg/L (0.4 μM) for β-carotene have been suggested below which cardiovascular risk might be increased. The present study performed on 897 presumably healthy subjects aged 40–60 years aimed to examine how modifiable lifestyle factors may be related to vitamin C and/or β-carotene deficiency. Gender, smoking, lack of regular physical activity and of daily fruit consumption (≥2/day), and social status (in particular, unemployment) were found to be significant risk factors for vitamin C deficiency. For β-carotene deficiency, the same factors were identified except social status; moreover, overweight and OC use in women were also found to have a deleterious effect. For non exposed subjects, the probability of developing vitamin C deficiency was 4% in men and 2.4% in women. This probability increased to 66.3% for men and to 44.3% for women (and even to 50.4% under OC use), when all risk factors were present. For β-carotene deficiency, the corresponding probabilities were equal to 29.7% in men and 13.7% in women (no risk factor present), and to 86.1% for men and 69.9% (91.6% for OC use) for women (all factors present), respectively.

Influenza outbreak in a well-vaccinated nursing home population in Belgium.

Abstract Elderly people in nursing home communities are vulnerable to contagious infections, including the influenza virus. Systematic anti-influenza vaccination is an important preventive measure; however, vaccination does not provide absolute protection. We report an outbreak of influenza A infection in a well-vaccinated nursing home population. Several factors can facilitate the occurrence of this type of outbreak. This report mainly addresses the discrepancy between the circulating viral strain and strains present in the recommended vaccine.

The ecology of health care in a Belgian area

Abstract Introduction: Focusing on the monthly prevalence of health problems and recourse to different levels of care of the population is an interesting approach to demonstrate the respective roles of different levels of health care. In the present study, the ecology of health care was studied in the region of Liège, Belgium. Method: A survey questioning people about their health problems was conducted in 2009 in two communes of the province of Liège. For each health problem, ‘health care’ was defined as contact with any qualified care provider. For each consultation, three elements were recorded: the profession of the health care provider; the place where the care was provided and the kind of health care received. Results: A total of 537 people were interviewed. The monthly prevalence of people who experienced a health problem during the previous month was 85·1%. The monthly prevalence of people who turned to a health care provider at least once during the month was 62·2%. The proportion of people turning to doctors, primarily local doctors, for a simple consultation was important (49·2%). Discussion: Our results are highly comparable with those of other studies. Recourse to a doctor is high (49%), which probably reflects the broad accessibility of health care in Belgium and maybe its overuse. Additional questions on the current and future organisation of the Belgian health care system are debated.

Long-term outcome of the humoral and cellular immune response of an H5N1 adjuvanted influenza vaccine in elderly persons: 2-year follow-up of a randomised open-label study

BackgroundOlder individuals often have a reduced immune response to influenza vaccination, which might be improved by administering a higher vaccine dose. We compared the immune response to two single doses of the AS03A-adjuvanted H5N1 pandemic vaccine (3.75 μg hemagglutinin of A/Vietnam/1194/2004) with that of two double vaccine doses (7.5 μg hemagglutinin) in adults aged ≥61 years. Here we report the 2-year persistence of the humoral and cellular immune response.MethodsIn this phase II, open-label study, healthy participants aged 61 to 88 years (median 68 years) were randomised (3:1:3:1) to receive two single doses of the AS03A-adjuvanted vaccine (1xH5N1-AS) or the non-adjuvanted vaccine (1xH5N1), or two double doses of the AS03A-adjuvanted vaccine (2xH5N1-AS) or the non-adjuvanted vaccine (2xH5N1), 21 days apart. Serum haemagglutination inhibition antibodies and cellular immune responses against A/Vietnam/1194/2004 were measured in all groups at months 12 and 24; neutralising antibodies were assessed in a subset of the adjuvanted groups. Serious adverse events and adverse events of specific interest were recorded.ResultsAt month 24, haemagglutination inhibition antibody seroprotection rates were 37.2% (95% CI 27.0% to 48.3%) for 1xH5N1-AS, 30.9% (95% CI 21.1% to 42.1%) for 2xH5N1-AS, 16.2% (95% CI 6.2% to 32.0%) for 1xH5N1, and 8.3% (95% CI 1.0% to 27.0%) for 2xH5N1. Haemagglutination inhibition antibody geometric mean titres were 17.6 (95% CI 13.7 to 22.5) for 1xH5N1-AS, 18.4 (95% CI 14.2 to 23.8) for 2xH5N1-AS, 12.3 (95% CI 8.9 to 16.9) for 1xH5N1 and 9.8 (95% CI 6.7 to 14.4) for 2xH5N1. The median frequency of antigen-specific CD4+ T cells per 106 T cells (25th quartile; 75th quartile) was 852 (482; 1477) for 1xH5N1-AS, 1147 (662; 1698) for 2xH5N1-AS, 556 (343; 749) for 1x-H5N1 and 673 (465; 1497) for 2xH5N1. Neutralising antibody geometric mean titres were 391.0 (95% CI 295.5 to 517.5) in the 1xH5N1-AS group and 382.8 (95% CI 317.4 to 461.6) in the 2xH5N1-AS group.ConclusionsAntibody levels declined substantially in all groups. Seroprotection rates, geometric mean titres for haemagglutination inhibition antibodies, and CD4+ T-cell responses tended to be higher in the AS03A-adjuvanted groups. There was no clear benefit, in terms of long-term persistence of the immune response, of doubling the dose of the adjuvanted vaccine. No safety concern was observed up to 24 months post-primary vaccination.Trial registrationNCT00397215 (7 November 2006).

Retrospective analysis of a suburban out-of-hours clinic in Belgium

Abstract Introduction: In many countries, out-of-hours medical care is under scrutiny. The aim of this article is to study the activities recorded by the first out-of-hours clinic that has been opened, as a pilot study, in two Walloon communes. Material and method: A retrospective analysis of anonymized data was conducted for 2009. Coding of diagnoses was conducted using the International Classification of Primary Care (ICPC-2). Results: A total of 3949 contacts were recorded in 2009 with the out-of-hours clinic, 3294 related to inhabitants of the two communes covered, which was equivalent to 13% of the total population in question. Compared to 7·2% of contacts between midnight and 8 a.m., 82·9% of contacts took place between 8 a.m. and 9 p.m., and 91·6% of contacts were handled locally, with only 8·4% resulting in hospitalization. In addition, 52% of contacts were with patients aged between 25 and 65; 29·9% of contacts were with paediatric patients (<15 years). Patients over the age of 65 made up 18% of contacts. The most common pathologies were respiratory (R). Analysis of flu diagnoses identified two epidemic peaks. Discussion: The suburban out-of-hours clinic studied fulfilled an important role in managing the demand for health care. The large majority of health problems were resolved locally, and the inhabitants did not need to go to hospital. Appointments between midnight and 8 a.m. were in the minority, which points towards adjusting the organization of the out-of-hours service during the night. The geriatric population is not highly over-represented contrary to what might be expected considering its largest number of pathologies. The on-call doctor’s skills profile should take account of the populations and morbidities encountered. Out-of-hours clinics could possibly play a sentinel role in terms of flu epidemics. Conclusion: This study describes a pilot suburban out-of-hours clinic which met three of recommendations set by the KCE in its report on out-of-hours care in general medicine: the organization of an out-of-hours clinic with logistical support, the use of a single telephone number and merging out-of-hours areas. While debate exists on the management of out-of-hours care, this study provides evidence on the role of the physician during these hours.

La littératie en santé, un levier pour des systèmes de soins plus équitables ? Des outils pour armer les professionnels et impliquer les institutions

This article briefly recalls why low levels of health literacy should be considered to constitute a public health issue. It then proposes the concept of health literacy as a possible lever to help health care systems to more effectively take social health inequalities into account. Finally, it provides concrete tools for field workers, both clinicians and quality of care managers, and emphasises the importance of an organizational approach to health literacy.

Quatre ans d’application de la loi de dépénalisation de l’euthanasie en Belgique

Legislation decriminalizing euthanasia came into effect in Belgium in 2002. Its application is monitored by a federal Commission, which submitted 2 reports to the Parliament, one covering the first 15 months of application and the other the years 2004 and 2005. This article analyzes and comments on the contents of these 2 documents, which provide interesting information on the medical practice of euthanasia in Belgium.