A patch placed on the skin could protect against flu as effectively as the traditional vaccine, research suggests.
For decades scientists have tried to find an alternative to flu jabs, which can cause patient anxiety, have to be administered by a medical professional and create biohazard waste.
University of Rochester experts now believe they have made a breakthrough, after testing their creation on mice.
They admitted one of the biggest setbacks is getting flu molecules across the skin’s hardy barrier, which keeps substances out.
The new patch – around the size of a standard plaster – contains synthetic proteins that make the skin more ‘permeable’, as well as a flu vaccine.
Trials on mice showed the patch ‘initiated a robust immune response’. And the rodents showed no increased risk of infection over the next three months, suggesting the patch did not permanently affect their skin barrier.
The team stress, however, that more animal studies need to be carried out, with the patch hopefully being tested in human trials ‘in the future’.
A needle-free patch (below) could protect against flu as effectively as the traditional vaccine (above), research suggests. When given to mice, they ‘initiated a robust immune response’
‘Scientists have been studying needle-free vaccine approaches for nearly two decades, but none of the technologies have lived up to the hype,’ study author Dr Benjamin Miller said.
‘Our patch overcomes a lot of the challenges faced by microneedle patches for vaccine delivery, the main method that’s been tested over the years.
‘And our efficacy and lack of toxicity make me excited about the prospect of a product that could have huge implications for global health.’
Flu jabs are effective but can come with a host of problems, including pain and some people have a fear of needles.
Patches have been suggested as an alternative but getting their ingredients across a patient’s skin was always an issue.
Eczema causes the skin to be ‘leaky’, allowing pollen, mould and other allergens into the body.
The Rochester scientists discovered the protein claudin-1 helps maintain the skin’s barrier and is significantly reduced in eczema sufferers.
Past research suggests lowering claudin-1’s expression in the skin cells of healthy donors makes them more permeable.
The team therefore set out to uncover whether inducing this permeability enables flu vaccine molecules to cross the skin.
Critically, this has to occur without allowing other molecules to enter the body, they wrote in the Journal of Investigative Dermatology.
In the first part of the experiment, the scientists developed synthetic proteins that inhibit claudin-1.
When tested in human skin cells, they identified one particular protein that does this without side effects.
They then designed a patch containing the synthetic protein and a recombinant flu vaccine. Recombinant means the jab is produced without using chicken eggs.
The patch was placed on mice to ‘prime’ their immune systems. The animals were then given a flu shot to further boost their immunity.
THE MYTHS AND FACTS ABOUT THE FLU SHOT
It is a myth that the flu shot can give you the flu.
‘There isn’t any live virus in the influenza vaccine so it’s impossible to get the flu from the vaccine,’ said Dr Tosh from the Mayo Clinic.
‘There was a live vaccine that’s not available any more, but it was impossible to get the flu from that too,’ he added.
CDC officials insist it is not too late to get the flu shot, despite evidence that this year’s vaccine is only 30 percent effective against H3N2.
The H3N2 strain of the virus has so far killed 85 adults and 20 children in the US.
Health officials say that the vaccine could be even more valuable now since it is more effective against strains which are only just emerging – including the H1N1 strain and various B viruses.
CDC figures show the majority of Americans do not get the flu shot and more and more parents are refusing to vaccinate their children.
In a second approach, the scientists first gave rodents a flu shot and then applied the patch.
The first scenario did not produce a significant immune response.
This suggests the patch may be ineffective in babies who have not been vaccinated against flu or exposed to the virus, the scientists claim.
However, the second approach did ‘initiate a robust immune response’ based on the increase of virus-fighting proteins in the mice’s blood.
This suggests the patch could boost pre-existing immunity for a baby aged six months or over who has been vaccinated or exposed to the flu virus.
In both scenarios, the patches were left on the mice’s backs for between 18 and 36 hours.
Once removed, the animals were not an increased risk of infection over the three months they were monitored.
This suggests the patch only briefly disrupts the skin’s barrier function, the scientists claim.
‘When we applied the patch the mouse skin became permeable for a short time,’ first author Dr Matthew Brewer said.
‘But as soon as the patch was removed the skin barrier started to close. We saw significant differences as early as one hour after removal and by 24 hours the skin was back to normal, which is great news from a safety standpoint.’
Flu jabs are effective, however, they have to be administered by medical personnel and require biohazard waste removal. This makes them impractical in developing countries, where need is greatest.
‘These countries don’t have the manpower to vaccinate entire populations,’ study author Dr Lisa Beck said.
‘On top of that, there’s an aversion to healthcare in many of these communities.
‘A needle is painful, it’s invasive, and that makes things more difficult when you are dealing with a cultural bias against preventative medicine.’
A patch could be a non-invasive way to quickly, and cheaply, vaccinate large numbers of people.
‘If you want to vaccinate a village in Africa you don’t want to do it with needles,’ Dr Miller added.
‘A patch doesn’t have to be refrigerated, it can be applied by anyone, and there are no concerns about disposal or needles getting reused.’
The researchers stress ‘a lot more work’ needs to be done to optimise the flu patch vaccine, like figuring out how long it should stay on the skin.
Every February, the World Health Organization (WHO) assesses which three or four flu strains it expects to be circulating the following winter in the northern hemisphere.
Based on these recommendations, vaccine manufacturers start producing jabs in March.
In the UK, young children are offered a yearly nasal spray to protect them against flu.
Officials in the US recommend children aged six months and over get a flu jab, while nasal spray vaccines are approved for people aged two-to-49, according to the Center for Disease Control and Prevention.