March 29, 2023 – Fungus infection candida auris can be problematic for some and deadly for others, especially for people at high risk due to advanced age or because they have a weakened immune system, called immunosuppression. A vaccine in development could offer hope.
The major problem is not necessarily the fungus itself, but the lack of treatment options. C.auris is resistant to two of the three main categories of antifungal therapies, and in some cases to all three.
“It’s the only real multidrug resistant fungus we have,” said Ashraf Ibrahim, PhD, a researcher at the Lundquist Institute in Torrance, California. He is also the main author of a new study assess how well Vitalex Biosciences’ monoclonal antibody vaccine might work to prevent or treat these infections.
Although relatively rare, C.auris infections can kill 30 to 70 percent of those most at risk, said Ibrahim, founder of Vitalex and an infectious disease physician at Harbor-UCLA Medical Center.
“So you don’t need a scientist to explain how dangerous this thing is.”
The CDC describes C.auris inasmuch as “urgent threat to public health.” C.auris the infection is mainly spread in health care settings. The fungus is not airborne, so you won’t catch it if someone sneezes or coughs. But it can survive on surfaces and on human skin.
If the vaccine continues to show promise, it could one day be used to boost immune protection for older people entering a nursing home, people being treated with multiple antibiotics in a hospital, and those likely to need intensive care. after a medical intervention.
The safest, so far
Public health officials want to strengthen surveillance of C.auris infections, Ibrahim said. Currently, people with healthy immune systems are not at greater risk unless they become vulnerable at some point. “If you have some kind of immunosuppression, it really takes advantage of it and starts to grow a lot – then starts to overgrow.”
The vaccine could kill C.auris mushrooms when combined in laboratory experiments. The vaccine also reduced the production of a “biofilm” by 30-40%. A fungal biofilm is a barrier that can prevent antifungal treatments from entering an infected cell or organ.
In experiments with mice with C.auris infection, for example, the vaccine reduced fungi in the kidneys and heart by 10 times. This means that there might be some protection against systemic bacteremia with C.auris, the researchers said.
Not the only mushroom in the family
You might assume that the monoclonal antibody vaccine is developed directly against C.auris. However, this is not the case. Scientists design the vaccine using Candida albicansa more common fungus and responsible for the majority of yeast infections in healthy women.
So why C. albicans? “We are currently working on both, but we are trying to get this vaccine to patients as soon as possible,” Ibrahim said.
C.auris infections have only been identified relatively recently compared to C. albicans, known for decades. Vitalex already had an ongoing program to develop a dual antigen vaccine against C. albicans. When they compared the two fungi, they found that they shared specific cell surface proteins that can be targeted to prevent either fungus from attaching and invading cells in the body.
“We said, ‘Well, we have the dual antigen vaccine in hand. Why not just try it in candida auris and see if it protects?’ said Ibrahim. “And it is clear that the vaccine works very well with candida auris.”
A possible role in the treatment
The vaccine has the potential not only to prevent infection, but as a treatment used in combination with other antifungals in someone already infected with C.auris. In research on an earlier version of the vaccine, if mice were vaccinated and also treated with an antifungal, there was a united beneficial effect, Ibrahim said.
“So pretty much like the story of COVID-19,” Ibrahim said. “If the vaccine doesn’t prevent the disease, adding a treatment option may actually prevent the person from dying.”
The next step is a toxicity study in rabbits to assess the safety of the vaccine. After that, clinical trials in humans could follow.
Still the first days
“candida auris is a significant concern for a very specific population,” said Aaron Glatt, MD, chief of infectious diseases at Mount Sinai South Nassau in New York, when asked to comment. “For the vast majority of the population right now, it’s not a concern. But as public health officials and as people with infectious diseases, we need to be very concerned about everyone,”
“Certainly the possibility of this becoming widespread would put more people at risk,” Glatt added.
Glatt advised caution in interpreting preliminary results like these. “It’s a very serious public health issue…but it’s not something everyone in the United States has to think about every moment right now.”