PARTING SHOT
Scientists trial patch to replace flu jab
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 (trypanophobia) who stand to benefit from this development, reported recently in the journal
Lancet. Doctors and public health experts have high hopes that vaccine patches will boost the number of people who get immunised against the flu.
Seasonal influenza is responsible for up to half a million deaths around the world each year, according to the World Health Organisation.
The fact that it usually involves poking a piece of metal into the muscle of your upper arm may have something to do with that low vaccination rate. (Some people also blame the time and expense involved in getting a flu shot.)
But a team led by Georgia Tech engineer Mark Prausnitz in the US 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. The trial involved 100 volunteers, who were randomly sorted into four groups.
Two of the groups were vaccinated with the patch, which resembles a plaster 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, healthcare 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 regular 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 immunisations 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.
After six months, at least 75 per cent 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, regardless of whether the patch was deployed by a health professional or a volunteer.
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 per cent of the volunteers who got vaccine patches said they would rather use them again than get a traditional flu shot or an intranasal vaccine. The authors of the study declared it a success on all fronts. –