Local doctor helps develop potential tuberculosis vaccine. Here’s why it is so promising

A potential new vaccine for tuberculosis is showing promise in early trials and has a local tie to the Tacoma area.

Dr. Christopher Fox of Sumner and a team of scientists developed the vaccine at the Access to Advanced Health Institute in Seattle, a nonprofit biotech research institute.

Fox told The News Tribune in an interview Monday that the vaccine has been under development for years and has several more years to go before approval and widespread use.

“It’s a long road ... to get a vaccine developed,” he said, “but the vaccine has been tested extensively in what we call pre-clinical testing for over a decade.”

Fox is an affiliate associate professor of global health at the University of Washington in Seattle and senior vice president of formulations at the institute. He is principal Investigator of the contract awarded by the National Institutes of Health, who funded the trial.

Results of a Phase 1 clinical trial published Monday in the journal Nature Communications demonstrated the TB vaccine’s safety and immune responses. The shot is administered in two doses, 56 days apart.

TB is among the most deadliest infectious diseases, killing 1.6 million worldwide in 2021, according to the World Health Organization.

The disease is curable with specific antibiotic regimens that patients follow for up to nine months. The WHO considers drug-resistant strains “a public health crisis and a health security threat,” making prevention important.

The study was the first human trial of the temperature-stable TB vaccine candidate, using a freeze-dried formulation that can be stored at elevated temperatures (nearly 100 degrees Fahrenheit) for months, making it easier to distribute and store in warmer climates.

“Think of hard-to-reach rural villages in Sub-Saharan Africa,” Fox said. “That three-month window of being able to distribute a vaccine and not have to control its temperature could be a major difference maker in having a vaccine that can actually reach everyone in the world.

“So we’re very excited about that advancement. And we’re the first to do that,” he added.

The sole approved TB vaccine available now, known as BCG, is more sensitive to temperature, among other issues.

Fox explained that the BCG vaccine is “given in many countries to infants. And it does a good job at generating appropriate immune responses in young children. But once they reach adolescence stage and then into adulthood, the vaccine really isn’t that effective anymore.”

He added, “There’s really a large unmet need to generate sufficient immune responses for adolescents and older.”

The BCG vaccine was developed in the 1920s but not widely used until after World War II. Fox says the new vaccine benefits from newer development methods.

“The kind of vaccines that we’ve developed are based on more modern synthetic technology, where you just take a piece of the protein of the mycobacterium — the tuberculosis bacteria,” he said. “And we make that synthetically, pair it with a synthetic adjuvant formulation. And that’s the vaccine.”

Part of the delay in getting the vaccine across the finish line is money.

“The funding’s a little bit more difficult to acquire for the kinds of diseases (such as TB) where there’s not likely to be a huge pharmaceutical profit margin,” Fox said.

The pandemic also led to delays in development.

“There were supply chain issues with reagents necessary to analyze the immune responses from the clinical trial,” Fox said. “And there were shutdowns at labs, including those that were participating in helping us analyze the samples from the clinical trial.

“So we had to wait for the labs to open back up and the supplies to become available to really get to the end.”

The vaccine is now in Phase 2 clinical testing to review efficacy.

“What we have right now is we know that it’s safe in healthy adults, and we know that it generates a robust immune response that looks like the kind of immune response that would lend itself to protecting you against TB,” he said. “But we don’t we don’t know that for sure yet until it gets tested.”