Research team

Expertise

dr Theeten conducted clinical trials with candidate vaccines against different diseases (hepatitis A and B, adult diphtheria‐tetanus‐pertussis booster, human papilloma virus, meningococcal C), as well as seroprevalence studies (based on immuno-assay; antibodies) on vaccine‐preventable diseases on a national level (in cooperation with the IPH) and vaccination coverage studies in Flanders. As a post-doctoral researcher, she continues supervising vaccination coverage and seroporevalence studies. Those require quantitative data collection and analysis, statistics and modeling techniques. She was funded by the Flemish Research Fund for a 3-year fellowship to look at cytomegalovirus infection and its association with immunosenescence (immuno-assays on humoral and cellular immunity level), and has promoted doctoral research on intradermal vaccination in infants (immuno-assay, imaging and quantitative analysis).. Currently she coordinates a project to monitor pneumococcal carriage in infants in Belgium (sample collection in a random selection of daycare centers and trough physicians; culture-based as well as molecular analysis, quantitative data analysis).

Assessment of the nasopharyngeal carriage of Streptococcus pneumoniae and other common pathogens in infants (6-30 months) with acute otitis media and in healthy infants (6-30 months) attending day-care centres in Belgium 01/10/2018 - 14/09/2020

Abstract

General use of vaccines against Streptococcus pneumoniae (S. pneumoniae) in infants has led to a decrease in the presence of the serotypes against which the vaccine was developed. It is a pathogen of which more than 90 different serotypes exist, of whom 10 to 13 are covered by the current vaccines. In order to gain a clear understanding of the S. pneumoniae serotypes carried by infants, and the impact of the vaccine used in the vaccination program, the current study was set up. As early as the first months of our lives S. pneumoniae is present in the nasal cavity and in the pharynx, mostly only temporary and innocuous, yet in some cases, in infants it may lead to infections such as otitis, pneumonia or meningitis. Since the presence of S. pneumoniae is more abundant in some circumstances, the current study focuses on infants between the age of 6 and 30 months either healthy and residing in day-care centres or suffering from an acute middle ear infection. Over a 4 year period, a swab will be taken from the nasal cavity of these infants (700 in first year, 900 in subsequent years, 6800 in total) to investigate presence, density and type of S. pneumoniae carriage, if any, as well as its resistance against antibiotics. The presence of some other pathogens that can cause airway or ear infections will be investigated too. The findings of this study will be extremely valuable to guide decisions on vaccine development, vaccine program, and recommendations on antibiotic treatment.

Researcher(s)

Research team(s)

Project type(s)

  • Research Project

Assessment of multi-serotype nasopharyngeal carriage of Streptococcus pneumoniae in infants (6-30 months) in Belgium: taking hidden carriage of pathogenic serotypes into account. 01/01/2018 - 31/12/2020

Abstract

General use of vaccines against Streptococcus pneumoniae (S. pneumoniae) in infants has led to a decrease in the presence of the serotypes against which the vaccine was developed. More than 90 different serotypes of this bacterium exist, of whom the 10 to 13 most pathogenic ones are covered by the current vaccines. As early as the first months of our lives S. pneumoniae is present in the nasal cavity and in the pharynx, mostly temporary and innocuous, yet in some cases, it may lead to infections such as otitis, pneumonia or meningitis. In order to gain a clear understanding of the S. pneumoniae serotypes carried by infants, and the impact of the vaccine used in the vaccination program, a carriage study was set up that is running 3 years from 2016 onward. The carriage study focuses on infants between the age of 6 and 30 months since the presence of S. pneumoniae is more abundant at this age. Swabs are taken from their nasal cavity to investigate presence and dominant type of S. pneumoniae carriage. To detect and monitor hidden carriage of vaccine serotypes or other pathogenic serotypes that can be present next to the dominant serotype, additional laboratory testing will be performed on a subsample of the collected swabs in the first and third year (245 each). The findings of this study will be extremely valuable to enhance insight in transmission of S pneumoniae and to guide decisions on vaccine development, vaccine program, and recommendations on antibiotic treatment.

Researcher(s)

Research team(s)

Project type(s)

  • Research Project

Assessment of the nasopharyngeal carriage of Streptococcus pneumoniae and other common pathogens in infants (6-30 months) with acute otitis media and in healthy infants (6-30 months) attending day-care centres in Belgium. 01/10/2016 - 30/09/2018

Abstract

General use of vaccines against Streptococcus pneumoniae (S. pneumoniae) in infants has led to a decrease in the presence of the serotypes against which the vaccine was developed. It is a pathogen of which more than 90 different serotypes exist, of whom 10 to 13 are covered by the current vaccines. In order to gain a clear understanding of the S. pneumoniae serotypes carried by infants, and the impact of the vaccine used in the vaccination program, the current study was set up. As early as the first months of our lives S. pneumoniae is present in the nasal cavity and in the pharynx, mostly only temporary and innocuous, yet in some cases, in infants it may lead to infections such as otitis, pneumonia or meningitis. Since the presence of S. pneumoniae is more abundant in some circumstances, the current study focuses on infants between the age of 6 and 30 months either healthy and residing in day-care centres or suffering from an acute middle ear infection. Over a 4 year period, a swab will be taken from the nasal cavity of these infants (700 in first year, 900 in subsequent years, 6800 in total) to investigate presence, density and type of S. pneumoniae carriage, if any, as well as its resistance against antibiotics. The presence of some other pathogens that can cause airway or ear infections will be investigated too. The findings of this study will be extremely valuable to guide decisions on vaccine development, vaccine program, and recommendations on antibiotic treatment.

Researcher(s)

Research team(s)

    Project type(s)

    • Research Project

    Vaccination coverage in Flanders, 2016 13/11/2015 - 31/12/2016

    Abstract

    This is a survey to assess vaccination coverage in infants (18-24 months), adolescents and mothers during pregnancy in Flanders. At home interviews to collect data on vaccination status and reasons for non-vaccination as well as attitudes towards vaccination are performed in a two-stage cluster sample of 875 infants, 1250 adolescents and 625 mothers who delivered less than three monts before. Vaccination data found at home are completed with vaccination data from physicians and Vaccinnet, the central registry. This study is a collaboration between CEV(UAntwerp) and KULeuven (LUVAC), and ordered by the Flemish government.

    Researcher(s)

    Research team(s)

      Project type(s)

      • Research Project

      Medical-technical research into intradermal injection in children and adolescents (PIDIC). 01/07/2014 - 30/06/2019

      Abstract

      To date fundamental knowledge is lacking regarding anatomical and physiological characteristics of the skin and skin thickness in children aged 0 to 18 years. Which results in the absence of applicable devices for accurate intradermal injections in this population. This doctoral MedTech research project aims to gather the anatomical and physiological characteristics of children and adolescents aged 0 to 18 years. First research will be done to gather anatomical and physiological characteristics of the skin of children and adolescents (WP 1). High-Frequency Ultrasound will be used to visualise the skin of children and measure thickness of the two outer skin layers. Both forearm and deltoid region will be evaluated as possible injection sites. Secondly the needle parameters will be investigated in an animal model (WP 2). Three species will be incorporated: mice, rats and piglets. Third, device prototypes will be tested in living piglets to evaluate for injection depth and distribution of the injected fluid. Lastly prototypes will be part of a clinical trial with vaccine antigen in children to evaluate for acceptability (pain perception and safety aspect) and immunogenicity. With this research, Novosanis, aims to development of a new device platform for intradermal injection.

      Researcher(s)

      Research team(s)

      Project type(s)

      • Research Project

      Cytomegalovirus(CMV) infection as a predictor of influenza vaccine response in the elderly. 01/02/2013 - 31/12/2013

      Abstract

      While it is generally accepted that ageing is associated with immune dysfunction and dysregulation, it has been suggested that this immune deterioration might be correlated with carrier status of CMV. Therefore, we elaborate to demonstrate a correlation between CMV serological status, CMV-specific T cell immunity and their association with responsiveness to influenza . This project will contribute to the identification of possible mechanisms involved in immunosenescence, which ultimately will contribute to new vaccine strategies including pre-vaccination screening, aiming an effective response in an individual whose immune system is in decline.

      Researcher(s)

      Research team(s)

        Project type(s)

        • Research Project

        Seroprevalention 2012. 13/12/2012 - 31/12/2012

        Abstract

        This project represents a formal research agreement between UA and on the other hand WIV. UA provides WIV research results mentioned in the title of the project under the conditions as stipulated in this contract.

        Researcher(s)

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          Project type(s)

          • Research Project

          The role of CMV-infection in age-related hyporesponsiveness to influenza vaccination. 01/10/2012 - 30/09/2015

          Abstract

          It is expected that worldwide in fewer than 10 years the population over the age of 65 will outnumber the population of children under the age of 5 for the first time in history. While it is generally accepted that ageing is associated with immune dysfunction and dysregulation (i.e. immunosenescence), it has been suggested that this immune deterioration might be correlated with persistent cytomegalovirus infection (CMV). We investigate the association between persistent CMV infection and immunosenescence in frail elderly living in nursing homes focusing on the humoral and cellular responsiveness to influenza vaccination. Results will be compared with findings in community-dwelling age-mates through a collaborative project. As outcome of this research we expect to identify yet unknown mechanisms involved in immunosenescence and to unravel its association with CMV infection. This knowledge will ultimately contribute to new prevention strategies which might include pre-vaccination screening, aiming a more effective response in an individual whose immune system is in decline.

          Researcher(s)

          Research team(s)

            Project type(s)

            • Research Project

            Study of vaccination coverage in Flanders in 2012. 04/01/2012 - 31/01/2013

            Abstract

            This project represents a formal research agreement between UA and on the other hand Vlaams Agentschap Z&G. UA provides Vlaams Agentschap Z&G research results mentioned in the title of the project under the conditions as stipulated in this contract.

            Researcher(s)

            Research team(s)

              Project type(s)

              • Research Project