Vaccine patch could make flu shots obsolete
Researchers have tested a flu vaccine patch in a human clinical trial and found that it delivered as much protection as a traditional jab with a needle.
Here’s an idea whose time has come: A flu shot that doesn’t require an actual shot.
For the first time, researchers have tested a flu vaccine patch in a human clinical trial and found that it delivered as much protection as a traditional jab with a needle.
It’s not just needle phobes who stand to benefit from this development, reported Tuesday in the journal Lancet. Doctors and public health experts have high hopes that vaccine patches will boost the number of people who get immunized against the flu.
Seasonal influenza is responsible for up to half a million deaths around the world each year, according to the World Health Organization. In the United States, the annual death toll since 2010 has ranged between 12,000 and 56,000. And yet the proportion of American adults who get a flu shot tends to hover around 40 percent.
The fact that it usually involves poking a piece of metal into the muscle of an upper arm may have something to do with that low vaccination rate. Tiny delivery system
But a team led by Georgia Tech engineer Mark Prausnitz has come up with an alternative method that uses “microneedles.” These tiny needles are so small that 100 of them, arrayed on a patch, can fit under your thumb. Yet they’re big enough to hold vaccine for three strains of the flu.
The microneedle patch was tested in a clinical trial conducted by Dr. Nadine Rouphael and colleagues at Emory University’s Hope Clinic in Decatur, Ga. The trial involved 100 volunteers, who were randomly sorted into four groups.
Two of the groups were vaccinated with the patch, which resembles a Band Aid and must be applied to the skin near the wrist for 20 minutes. The procedure was so straightforward that one group of volunteers was able to administer the vaccine themselves. (In the other group, health care professionals did the job.) Inspection of the used vaccine patches revealed that the microneedles dissolved during the 20 minutes they were on the skin.
A third group received a traditional flu shot using a needle, and a fourth group got a patch that looked like the real thing but contained a placebo.
The researchers checked in on the volunteers 28 days after their immunizations and found that flu antibody levels were “significantly higher” in the three groups that got the vaccine than in the group that got the placebo.
What’s more, the two groups that got the vaccine via a patch had about the same antibody levels as the group that got the traditional shot. In addition, the volunteers who put the patches on themselves got the same protection as the volunteers whose patches were administered by health professionals. Slightly smaller dose
After six months, at least 75 percent of volunteers in all three vaccine groups were still being protected, according to the study.
The traditional shot contained at least 15 micrograms of antigens (the part of the flu virus that triggers an immune response) to each of the three strains of flu. The patches delivered a slightly smaller dose of antigens.
None of the study volunteers had serious side effects. The groups that got patches had mild skin reactions that were not seen in the regular needle group, while the volunteers in the regular needle group were more likely to experience pain.
Overall, 70 percent of the volunteers who got vaccine patches said they’d rather use them again than get a traditional flu shot or an intranasal vaccine.