Written by By Kara Carlson-Raybould, CNN
Vaccines work because of the immune system. It learns to recognize a poison, spot it in its path and destroy it. In the process, other pathologies are prevented. But what if the technology behind the vaccine to prevent illness was improved?
A new study from scientists at the University of Colorado School of Medicine (CU-OSM) and the Galvin Global Vaccine Program demonstrates that the process could change in a major way — and have global implications for the fight against human and animal disease.
“By characterizing the ways that natural immunity to a deadly disease can be increased or diminished in vaccines, we’ve opened the door to new approaches for enhancing the vaccines that we use against diseases like polio, polio-like poliovirus and HIV,” says lead study author Mark Kamarsky, Associate Professor of Medicine and microbiology and immunology at CU-OSM.
Imagine we replaced HIV with a more potent vaccine. In that case, would the Global Flu Vaccine Alliance still be able to deliver 6 billion doses of flu vaccine globally every year? (That’s the number of doses it plans to deliver every year.) Or would some national governments cut back — because there’s only one virus to vaccinate against, not the 10 strains of infectious disease you are currently seeing in the marketplace? And how would that impact how much time you spend washing your hands — the next best thing to a shot in the arm?
By modelling the response of the body in an experiment with the polio virus, Kamarsky says that if he were making a vaccine today, he would “take advantage of high levels of natural immunity to that disease.”
For what Kamarsky refers to as “self-limiting” diseases, like HIV or Ebola, he would seek to make vaccines that were more potent and efficient. However, we are dealing with viruses that have evolved to be “highly drug resistant” and require ever more-powerful techniques to neutralize their potency, he says.
While methods to upgrade existing vaccines can be effective, Kamarsky notes that some have been limited by their ability to protect a small number of cells. While sometimes targeted vaccines may be effective, other vaccines — including West Nile and influenza — don’t really vaccinate against viruses at all.
The vaccine that they have developed, on the other hand, works on the basis of not only vaccinating one cell in a system, but a group of cells, cells that are then exposed to the vaccine — and not just a cell in isolation.
If the immune system does recognize the pathogen, it may then respond with further action — by marking another cell in a specific tissue region or clotting a blood vessel — all of which work in concert to increase protection.
The CU-OSM team also modeled the impact of manipulating immune response to cellular-based vaccines on certain pathogens in order to understand how a change in immune response could improve some vaccines and potentially render them less effective against others. The treatment affects the shape of a receptor on the surface of cells, allowing them to communicate with one another, improving either efficiency or effectiveness in terms of the pathogen’s time in the body or when the vaccine is administered.
While the CU-OSM team has only tested vaccines tested in animal models to date, it hopes this work can be used to inform the development of strategies for human vaccine development.
“We’re excited by the potential of these findings. It’s been nearly 30 years since the introduction of the first humanized vaccine, and almost 40 years since the first real humanized HIV vaccine. While our rate of improvement has been quite slow, advances in this area will create new opportunities for treatment and prevention,” Kamarsky says.