Feb 13, 2012Science and Technology
User-friendly delivery of dry powder vaccines

Needle reuse is illegal in developed countries, and rightly so. Sadly, this practice still takes places in many undeveloped countries, and is a source of significant spread of disease and infection. In particular, needle reuse has triggered the dissemination of measles, mumps, rubella and HPV, all of which are currently preventable by vaccination. Thus, there is an urgent need for a vaccine delivery system that does not rely on needles for use in developing countries. Professor Bob Sievers of the University of Colorado at Boulder, through a generous grant from the Bill & Melinda Gates Foundation, has filed a patent application for just such a vaccine and accompanying device.

When developing the present invention, Sievers considered both the dangers of needle use, as well as the physical challenges present in delivering vaccinations to remote locations in developing countries – extreme heat and cold, lack of electricity, and transportation by foot, to name a few. The hepatitis vaccination, for example, is ineffective if frozen, because the aluminum hydroxide activator does not stay bound to the active protein if it freezes. Even if stored at room temperature, the vaccine may be exposed to freezing temperatures overnight, thereby rendering the vaccine useless without the administrators’ knowledge.

Human lungs have the surface area of a tennis court, so they present an especially good target for vaccines. The patent discloses the use of a dry powder vaccine, which presents a viable solution to the above-stated challenges. Powder-based substances are inherently more stable than their liquid counterparts, and the present invention is protected from freezing to negative twenty degrees Fahrenheit. Additionally, removing water or ice from the vaccine or its containers significantly cuts down on weight concerns, making delivery to remote villages literally less burdensome. Furthermore, the accompanying patented device for vaccine delivery by inhalation obviates the need for sterility. The PuffHaler, as the device is named, operates via a hand-squeeze pump, such that electricity is not needed for use.

Contamination of liquid vaccines in multi-dose containers is suspected in clusters of sudden deaths, believed to be caused by toxic shock syndrome. The opened vaccine vials act as culture media for bacterial growth. Powders are significantly more difficult to contaminate than liquids, particularly when stored in aluminum foil-wrapped individual dose blister packs, as disclosed in Sievers’ invention.

In addition to obviating the need for electricity, water, temperature regulation or proper waste disposal, the disclosed invention could also save $700 million if it replaced the injection-based vaccination system presently in use.

The dry powder measles vaccine has been tested on the Rhesus monkey with one hundred percent efficacy. On this basis, regulatory officials in India -- where two-thirds of all measles-related deaths occur, yet only twenty-nine percent of children receive measles vaccinations on time -- have agreed to human testing beginning later this year. With five hundred people dying every day from measles in undeveloped countries, it is imperative that a technology such as this is put into use as soon as possible so that existing vaccines may prevent these deaths in the future. 


Single doses, ease and safety of delivery, lower cost. 


Thus far, this vaccination delivery method has only been tested on monkeys. Vaccinations for measles are generally given to children, but because of informed consent issues, this is not possible during the testing phase. However, India’s willingness to participate in the testing process this year will hopefully allow swift approval of this vaccine so that administration can begin as soon as possible. 

Kristin WallMind-boggling, isn't it? Targeting the lungs through inhalable vaccines makes a lot of sense, given that massive surface area.
Feb 17, 2012
Andrei IvanovHuman lungs have the surface area of a tennis court?! I never knew, that is amazing. This powder vaccine innovation is very helpful.
Feb 16, 2012