New vaccine-delivery options point away from needles
Studies have found that up to 10 percent of U.S. adults are so frightened of needles that they will avoid medical treatment that might require a shot
Scripps Howard News Service
The injection. The jab. A little pinch. Even "this won't hurt a bit"shots tend to leave many people squeamish.
Studies have found that up to 10 percent of U.S. adults are so frightened of needles that they'll avoid getting any medical treatment that might require getting a shot.
But scientists and drug companies are moving rapidly ahead with several new technologies that aim to deliver vaccines and other therapies needle-free.
One of the favored approaches is the inhalable vaccine, which has been around as a weakened live vaccine against the flu — FluMist — for some time.
Researchers at the University of Colorado at Boulder have developed a prototype for a new generation of inhaled vaccines based in part on studies that were originally done to understand how people inhale tiny airborne droplets of air pollution.
Safety and then larger effectiveness trials of a weakened measles vaccine delivered through the inhalant powder are slated to start in India this summer. In animal tests, the inhaler has been as effective in delivering the vaccine as traditional injections, the researchers say.
Robert Sievers, a professor of chemistry and biochemistry who heads the development team, said the process works by mixing the measles virus with carbon dioxide that's in a "supercritical state — part gas, part liquid"that produces microscopic bubbles and droplets that are dried into an inhalable powder.
The dose is actually dispensed using a small plastic sack that has an opening like the mouth of a plastic water bottle. With a good squeeze and a deep breath from the sack, "a child could be effectively vaccinated," Sievers said.
Aside from use for vaccines against childhood diseases, the researchers suggest the technology might offer another way to attack multidrug-resistant tuberculosis and to deliver vaccines against cervical cancer and perhaps other cancers.
Beyond eliminating needles and the risks of infection associated with them, the new inhalant system also offers a dry vaccine that doesn't require refrigeration or other special handling. For measles, it can be made at a cost of about 26 cents per dose — about the same as for an injectable dose.
Another dry-powder system, developed by the Connecticut-based MannKind Corp., has proved effective at delivering an ultra-fast-acting dose of insulin through the lungs, rather than by injection, giving some diabetics a near-natural rush of the hormone similar to that experienced by non-diabetics immediately after a meal.
The company expects that the same sort of devices could be used to deliver a variety of vaccines.
Another Colorado enterprise, a company called Pharmajet, has developed another no-needle technology that actually uses spring-loaded pressure to inject vaccine through the skin. A small plastic cylinder full of vaccine does not look like a needle, although there's still a tiny sting from the serum going through the skin.
The U.S. Food and Drug Administration approved the system last year in time to be used to deliver seasonal-flu shots in Colorado and New Jersey last fall.
Several groups of researchers and companies are also working toward vaccine-patch delivery systems that would carry active ingredients through the skin using small particles.
One group, at the University of Michigan, has designed a protein than can carry vaccine through cell membranes into the interior of cells, particularly immune cells just under the skin. Tests on mice have achieved activation of the immune system equal to that brought about by conventional vaccines.
Scientists at Queensland University in Australia have been working on a "nanopatch"vaccine that utilizes tiny projections — to small to feel — that nonetheless penetrate the skin deeply enough to activate those same immune cells. They're still testing with mice, but say one advantage of the system is that it can achieve the same level of immunity as shots, using about 100 times less actual vaccine.
And an Austrian firm, Intercell, recently bought a Maryland company that had developed a two-step, needle-free stick-on vaccination method using two patches — one an abrasive that serves to peel off a thin outer layer of skin, which is then replaced by a second patch with the actual vaccine, now capable of being easily absorbed through the remaining layers.
They are already being tested on people and could be approved for flu vaccination soon. Intercell is working with the vaccine giant GlaxoSmithKline on the new product.
Contact Lee Bowman at BowmanL@shns.com