A common misconception that many people have around vaccines is that they’re a one shot deal that provides you with complete immunity from the disease in question. The efficacy of a vaccine is judged by how much it lowers the incident rate of a particular disease given ideal conditions and typically that number is high enough that herd immunity takes care of the rest. The flu vaccine is a great example of a vaccine that doesn’t provide full immunity to the disease in question (due to its highly mutable nature) but it does however give your immune system some tools with which to fight off variants of the disease should you get infected. Thus anything we can do to improve the efficacy of vaccines is important and it just so happens that lasers might be the next big thing.
Researchers at the Massachusetts General Hospital in conjunction with the Harvard-MIT Division of Health Science and Technology investigated the application of a cosmetic laser to an injection site prior to administering a vaccine. The research was primarily focused on improving the efficacy and duration of the protection offered by the influenza vaccine as its current levels could do with some improvement. The results they found were quite interesting, showing a 4 to 7 fold increase in immune response to the vaccine. Interestingly the results could not be replicated by simply increasing the dose of the vaccine, signalling that there was another mechanism in effect. The results also lend credence to one line of thinking of how adjuvants work, opening up new avenues for research.
Cosmetic lasers work by stimulating the body’s in built healing processes. Essentially they damage your dermis (without damaging the outer layer of skin) which causes an inflammation response at the site. For cosmetic purposes this is desirable as it promotes the renewal of skin cells at that site, making the skin look more youthful. For vaccines however this inflammatory response brings antigen-presenting cells to the site, the cells which are responsible for binding to pathogens or other harmful cells, which when faced with the vaccine rapidly bind to it. Interestingly enough the effect is most pronounced when used in conjunction with a typical adjuvant (Imiquimod, a topical cream) which also promotes an immune response at the site.
Interestingly this isn’t the first time that trauma at the injection site was used to promote the immune response. The smallpox vaccine used a bifurcated (split in two) needle which caused a rather unnerving wound at the injection site. This reduced the amount of vaccine required by about 4 times and resulted in the same effect, drastically reducing the cost required to vaccinate large populations. The cosmetic laser is a better approach due to the way it’s administered, reducing the chance for opportunistic infections and nocebo effects that might arise from the treatment.
Best of all whilst the research focused primarily on the influenza vaccine the same method appears to work for some of the other common vaccines. It’s still early days though as there’s a wide range of vaccines out there that will need to be tested with this method before it becomes standard procedure. Still anything that increases the effectiveness of an already high effective tool is great news as it means that these diseases will become less prevalent and, hopefully, we can reduce our mortality rates from them as well.
But also it’s just so freaking cool that lasers (LASERS!) are the things making vaccines better. It makes me unreasonably happy, for some reason…