Inhaled Measles Vaccine Closer to a Reality

The first dry powder inhalable measles vaccine will soon be ready for testing in humans, researchers announced at the 238th meeting of the American Chemical Society in Washington, DC.

Dr. Robert Sievers of the University of Colorado in Boulder, who is heading up development of the vaccine, pointed out that the goal is to make immunization possible in isolated areas of developing countries, where refrigeration, clean water, and sterile needles are often unavailable and measles is still endemic.

Measles kills more than 900,000 children each year in less developed parts of the world, according to the World Health Organization (WHO).

The research team expects to start testing the vaccine next year in India, Sievers told Reuters Health.

Basically, to make the vaccine, a weakened form of the measles virus is mixed with "supercritical" carbon dioxide - part gas, part liquid - to produce microscopic bubbles and droplets, which are then dried to make the inhalable powder.

The powder can be stored for at least a year at 2 to 8 degrees C, the developers say. Furthermore, it also passes the World Health Organization's 7-days-at-37-degrees test, remaining potent even in those circumstances.

The research team has also developed low-cost inhalers for the powder "with performances virtually equivalent to an FDA-approved active inhaler."

The powder is sealed in individual sacs to minimize contamination. "By taking one deep breath" from a sac, "a child could be efficiently vaccinated," the researchers note in a prepared statement.

Development of the inhalable vaccine has been funded by a grant from the Grand Challenges in Global Health Initiative of the Bill and Melinda Gates Foundation.

One constraint of the challenge, Sievers explained, is that the cost not exceed 26 cents per dose, the price of currently available injectable vaccines. This target has essentially been met, with the vaccine presently costing about 17 cents per dose and the delivery device costing about 10 cents, Sievers said.

Although the concept of using inhalable powder to deliver measles vaccine came in response to public health challenges in remote, poverty-stricken regions, Sievers also believes this approach "is beautifully suited for an influenza vaccine" as well.

"It's so promising.... We need to start working on it now" for other indications, he said.