Addition of an extra adjuvant (additive) to the current pertussis vaccines could enhance the effectivity of these vaccines. Moreover, a new generation vaccine, an outer-membrane vesicle vaccine, might be even more effective in protecting against pertussis. Based on this research, Jolanda Brummelman, of the National Institute for Public Health and the Environment (RIVM National Institute for Public Health and the Environment ), will obtain her doctorate degree at the University Utrecht on April 28th .

An increased incidence in pertussis was observed during the last decades, despite vaccination. RIVM National Institute for Public Health and the Environment performs research to gain more insight in the characteristics of the immune defense against Bordetella pertussis, the bacterium causing pertussis, to identify better ways to protect against pertussis. Jolanda Brummelman investigated the type of immune response that provides long-term and effective protection against Bordetella pertussis using mouse models. The research was focused on the role of the CD4+ T cell. This cell type regulates the clearance of the bacteria from the airways and can provide a faster immune response after a subsequent encounter with this bacterial pathogen.

The research showed that less effective T cells were induced by pertussis vaccination than after natural infection. This response could be improved by adding   an extra adjuvant to the current vaccine. Such adjuvant needs to be carefully selected so that it induces the optimal T cells. The fundamental research by Jolanda Brummelman showed that this approach worked in mice.

A new generation vaccine, an outer-membrane vesicle vaccine (OMV vaccine), could provide superior protection against pertussis. This type of vaccine contains a broad range of proteins, which leads to the induction of an immune response with a broad antigen specificity. Moreover, OMV vaccines contain intrinsic adjuvant activities, making addition of adjuvants unnecessary. Brummelman investigated such OMV vaccine in mice in collaboration with IntraVacc, developer of vaccine concepts and technologies. OMV vaccination induced protection involving the optimal T cell response, especially when administered directly in the lungs of the mice. Further research is necessary to evaluate if and how these findings can be translated to the human situation.

This research was carried out in the framework of RIVM Strategic Programme (SPR), in which expertise and innovative projects prepare RIVM to respond to future issues in health and sustainability.

The co-supervisors are dr. Cécile van Els and dr. Wanda Han (former employee RIVM). The fundamental knowledge gained in this project is relevant for the development of improved pertussis vaccines and vaccination strategies. Moreover, this knowledge is important for supporting the government in her policy regarding pertussis prevention via vaccination. You can find the abstract of the thesis under 'Download'. The complete thesis will be published later this year.