Valley Fever Vaccine Update
Several years ago, investigators at the University of Arizona created delta-cps1. This is a mutant strain of Valley Fever fungus that is missing a large gene. Delta-cps1 does not cause disease in several strains of mice, including those with no lymphocytes and mice that have had their bone marrow suppressed by chemotherapy. We have discovered that the delta-cps1 strain is unable to grow in the host very long and mainly dies off in the first week or two. This live, avirulent vaccine is being prepared for vaccine licensing to prevent Valley Fever in dogs, followed by studies to develop the vaccine for people.
The Canine Valley Fever Vaccine Project is a joint public/private venture of the Valley Fever Center for Excellence (University of Arizona) and Anivive Lifesciences, Inc., through an NIH grant [RO1-AI-132140] to develop a vaccine to prevent Valley Fever in dogs.
Delta-cps1 protects dogs from Valley Fever lung infection
Following some delays that occurred for several months during the pandemic in 2020, the project is back on track and continuing toward licensing. Some hurdles have been cleared. A study showed that the delta-cps1 vaccine actually protects dogs from Valley Fever lung infection when given as a two dose series. All the dogs given prime and booster vaccines had low lung and disease scores and normal or minimally abnormal lung x-rays, indicating a high level of protection against a stringent challenge. The vaccine caused no systemic adverse effects in the dogs studied. Though mild to moderate swelling at the injection site was common, they all resolved, most of them within 2 weeks, and the dogs in the study did not exhibit pain or itching from the vaccine. Details regarding the study and outcome are available in this recently published manuscript.
Formulation is the determination of what ingredients go into each vial of vaccine to stabilize for storage so the vaccine can be shipped to veterinarians and kept on hand until administered to dogs. Formulations have to
Protect the delta-cps1 vaccine strain from loss of viability or damage during storage.
Protect the delta-cps1 live spores from loss of viability due to the drying process. Dry products have a longer shelf life and proper drying preserves the viability of live vaccines.
Contain ingredients that are safe for dogs and are unlikely to cause adverse effects.
Finding a formulation that adequately protects and stabilizes the spores has proven challenging though researchers appear to be refining this and coming closer to a product since work has been able to proceed without more pandemic delays.
Veterinary vaccines are licensed by the USDA Center for Veterinary Biologics. Hennessy Research Associates (Kansas City, MO) has partnered with Anivive to license and manufacture the vaccine. The UA, Anivive, and HRA continue to work closely to provide the licensing package to the USDA to get approval for licensing in dogs. Some studies remain to be completed regarding safety and avirulence of the vaccine in dogs and the environment. These are underway and anticipated to be completed in 2022.
Canine safety study
A canine safety study in community dogs is part of the requirement for licensing of the delta-cps1vaccine. This will involve thousands of dogs in different locations. Dogs will receive two doses of the vaccine and be monitored for adverse effects. The safety data are a critical component of USDA’s evaluation of delta-cps1 for licensing. If you may be interested in your dog participating in the safety studies, which are tentatively anticipated to occur early in 2023, you may sign up on the secure database at this link. The database collects your name and contact information so we may inform you about how to participate in the study when it does finally take place.
Vaccine for people
An additional grant has been written and the delta-cps1 vaccine is beginning studies to develop it for use in humans. The progress of the dog vaccine, especially positive results with safety and efficacy as it moves into community trials and use, will be helpful for the development of the human vaccine.