Measles is a respiratory disease caused by a highly-contagious airborne virus, and kills over 145,000 people around the globe each year, predominantly children younger than five. While there is already a wonderful measles vaccine available (that also prevents mumps, rubella, and chickenpox), it is not always feasible to store the liquid or have an adequate supply of clean needles in developing regions of the world. A powdered vaccine that is inhaled with a puff of air has just gone through its first human clinical trial, and the researchers have discovered that there were no adverse side effects associated with the vaccine. The paper was published in the journal Vaccine.
Developing a vaccine that is inhaled rather than injected has some fairly great advantages. When multiple vaccine doses need to be drawn out of one vial, there is an inherent risk for contamination. A powdered vaccine not only eliminates this risk, but it also relieves the anxiety that is associated with injections and all of the other baggage associated with using needles.
“Delivering vaccines in the conventional way, with needle injections, poses some serious challenges, especially in resource-poor parts of the world,” Robert Sievers said in a press release. Sievers is a chemist at the University of Colorado in Boulder, and one of the study’s co-authors. "You don't need to worry about needles; you don't need to worry about reconstituting vaccines with clean water; you don't need to worry about disposal of sharps waste or other vaccine wastage issues; and dry delivery is cheaper.”
The study used 60 healthy men aged 18-45 who were already confirmed to have measles antibodies from prior vaccination or contact with the disease. They were then randomly split into three even groups: two groups received the powdered vaccine via one of two inhaler devices, and the control group received the standard measles vaccine injection.
“Out of an abundance of caution, we test first in people who have already had the disease, or been injected earlier by needles with liquid vaccines," Sievers explained.
The test subjects were followed for 180 days after the administration of the vaccine, with participants keeping a detailed log of any side effects they experienced. None of the participants reported any clinically-relevant reactions to the vaccine. Even in a small trial such as this, it is a good sign as the team moves forward.
Because this was a Phase 1 trial, the researchers were only concerned with the safety of the vaccine, though the researchers did measure antibody levels before and after receiving the vaccine. Most of the participants already had high levels of antibodies before the study, so there wasn’t statistically relevant information that hints at efficacy from this study. Future trials will include women and children, including those who do not already have measles antibodies.
