While I may not be as chicken as I once was where receiving a vaccine is concerned, I cannot say that I ever really look forward to being vaccinated, and I expect that most people feel the same.
The last time a needle was plunged through my skin, during the COVID-19 pandemic, I was lucky enough to not suffer any after-affects, but I know a good few people who claimed to have done so.
Unsurprisingly, the news that scientists might be on the path to developing vaccines that could simply be rubbed onto the skin is more than welcome. In addition to reducing patient stress and discomfort, application would be quick and, cheap – no needles or syringes required and, probably not a great deal of skill in application!
The research is ongoing and, I should point out, currently only directed at offering protection to humans, whether needle-phobic or not. Yet the ease of application would make skin applied vaccines as beneficial in the hatchery as they could be in the doctor’s surgery, and the team behind the work believe that the approach could work for viruses, bacteria, fungi and single-celled parasites.
The work on a skin applied vaccine has been carried out at Stanford Medicine, of Stanford University in the U.S., where its research team worked with Staphylococcus epidermidis, a skin colonizing bacterium that is generally harmless to humans and found on every hair follicle of almost every person on the planet.
Higher than expected response
The researchers had already learned that the immune system mounts a more aggressive response against S. epidermidis than anyone had been previously thought, and decided to discover how a mouse’s immune system might respond to it, given that mice are not normally colonized by the bacterium.
S. epidermidis was simply applied to the head of mice, without shaving their fur. Initially, antibody levels increased slowly but, at six weeks, they had reached a higher concentration than would be expected from standard vaccination, and they stayed at that level. The antibody response was as high as if the reaction had been to a pathogen.
The Stanford team then engineered S. epidermidis to contain a piece of tetanus toxin to see if the mouse immune system would respond to that. Mice were administered either the unadulterated bacterium or the bioengineered version with the tetanus fragment, with several applications over six weeks. The mice swabbed with the bioengineered S. epidermidis developed extremely high levels of antibodies against the tetanus toxin.
When subsequently injected with the tetanus toxin, those mice given the unaltered S. epidermidis died, while those that received the modified version remained symptom free.
The research team then generated the tetanus toxin fragment in a bioreactor, and added it S. epidermidis‘ surface. When swabbed onto mice a powerful immune response was generated, resulting in enough antibodies to protect mice against six-times the lethal dose.
Vaccination via rubbing a vaccine into the hair or skin sounds appealing to me, and if it does to you, you can read more in journal Nature.
Of course, there is a lot more work to be done and, to date, experiments have not been carried out in avian species. Whether birds would generate a similar immune response remains unknown. However, should the same approach work for poultry, the simplicity of administration, compared to current methods of vaccinating day old chicks, along its low cost, could result in widespread adoption.
