The discovery of a virtual scientific miracle is close at hand and UCSB researchers Douglas Heithoff and Michael Mahan are the masterminds behind it. They have, in collaboration with University of Utah scientists Elena Enioutina, Diana Bareyan, and Raymond Daynes, produced a single vaccine that can protect against multiple strains of bacteria.
The current state of vaccination can only protect against a restricted number of closely related strains, for instance, as in flu vaccines. As Mahan put it, the reason “flu vaccines need to be administered every year [is] because different flu strains arise every year.” If the new breed of vaccine continues to perform as it has in studies thus far, it will put the medical field perpetually one step ahead of evolving bacteria rather than in a constant arms race. Mahan and Heithoff cite their desire to find a broad-spectrum vaccine as motivation behind their research.
The key discovery made by the group was how to flip off a “genetic switch” that had allowed the bacteria to attack the body’s immune system. After the switch is disabled, the bacteria also become more visible to the immune system and can be targeted. Another advantage of the new vaccine is that it does not induce a certain group of inhibitory immune cells, as current vaccines often do, that are known to dampen cancer patients’ immune systems and increase their susceptibility to disease.
Salmonella is the first bacteria the researchers decided to tackle because, in Mahan’s words, “It’s endemic worldwide. It’s not a carnivore issue - it’s everybody’s issue since fruits and vegetables are often the source of infection.” More than 1.5 million cases per year of Salmonella infection-which causes food and blood poisoning-occur in the U.S. alone; a vaccine that attacks a wider range of bacteria strains could prove life saving.
The research findings on the suppression of inhibitory immune cells may shine a light on the immune declines in cancer patients and those naturally occurring during the aging process. The presence of inhibitory cells, Mahan conjectured, “may explain why the elderly are more susceptible to infection and why they are more difficult to effectively vaccinate.”
The research is still in its preliminary stages and is being funded by the National Institutes of Health, the United States Department of Agriculture, and the Mathers Research Foundation. Currently the vaccine is being tested on livestock, the main source of human infection.
Look for a detailed description of the study, including how the research team finessed their way to the new vaccine, in a paper they will publish in the November issue of the scientific journal Infection and Immunity.