Powder to the people
|PhD ceremony:||Mr W.F. Tonnis|
|When:||December 05, 2014|
|Supervisor:||prof. dr. H.W. (Henderik Willem) Frijlink|
|Co-supervisor:||dr. W.L.J. (Wouter) Hinrichs|
|Where:||Academy building RUG|
Various aspects of vaccination via the lungs were studies in the research of Wouter Tonnis. Over the last decades, vaccines have prevented many infectious diseases and deaths worldwide. Disadvantages of current vaccine products are their relatively short shelf life and their administration by needle. The short shelf life makes transport to rural areas in developing countries difficult or even impossible. Furthermore, administration by injection creates the risk of transmission of diseases like HIV and hepatitis B, due to the re-use of needles or accidental needle-stick injuries, requires the help of trained healthcare workers, and persons with needle-phobia might refuse vaccination. All these disadvantages could be overcome by processing the vaccine into a dry and stable powder that can be administered by inhalation.
First, it was investigated which excipients are needed during drying to obtain powder with optimal stability. These excipients were used to prepare powders of the hepatitis B vaccine. The powders could be stored for 3 months at 60 °C without affecting the activity of the vaccine while the current liquid formulation was completely destroyed within one week at 60 °C. Furthermore it was found that the hepatitis B vaccine needs to be delivered to the deep lungs for a good immune response. Also, a brand new device was developed to properly administer these powders to the lungs of mice, which makes further investigation of vaccination via the lungs possible. Finally, pulmonary vaccination was successfully applied to chickens to protect them against bird flu. This strategy could be applied during an outbreak of bird flu as an alternative to pre-emptive culling.