At his laboratory at the University of Hawaii John A. Burns School of Medicine in Honolulu, researcher Axel Lehrer has several vaccine candidates that potentially could save lives around the globe.
The vaccines, which have been under development for more than a decade with promising results, target the Sudan ebolavirus, which is driving the current outbreak in Uganda; the Zaire ebolavirus; and the Marburg virus, which caused an outbreak in Guinea last summer.
Studies have shown these vaccines offer full protection in mice and monkeys, said Lehrer, an associate professor at JABSOM’s Department of Tropical Medicine, Medical Microbiology and Pharmacology. He hopes they can now be taken to the next level, with human clinical trials, and ultimately — put to use in the real world.
What sets these vaccines apart is that they are thermostable, meaning they can be stored on a shelf without cold refrigeration.
“We’ve been working on this vaccine for a long time,” said Lehrer. “We developed vaccines that can be stored on the shelf. That’s why we thought we had something the world might need.”
The vaccines can be reconstituted with a little water immediately prior to use, said Lehrer, which is useful for parts of the world where the power supply can be uncertain, and simplifies storage and distribution efforts globally.
But millions of dollars in funding is needed, along with access to clinical grade materials and regulatory approvals from the U.S. Food and Drug Administration to get on the path to clinical trials.
What would help, he said, is if Hawaii had a manufacturing facility that could make the vaccines and other medical products locally. It would be a worthwhile investment not only for JABSOM but for the state, especially for pandemic preparedness.
Ebola outbreak
The World Health Organization, meanwhile, is working urgently to support the Ugandan government in its response to the Ebola outbreak, which health authorities declared on Sept. 20.
According to WHO, the declaration came after a case was confirmed in a 24-year-old village man in the Mubende district of central Uganda. The man suffered from a wide range of symptoms, including high-grade fever, a dry cough, vomiting of blood, diarrhea and abdominal pain. He died the day that tests confirmed he had the Sudan ebolavirus.
The outbreak caused by the Sudan ebolavirus has now spread to seven districts, including the capital, Kampala. Officials have confirmed at least 130 Ebola cases and more than 40 deaths.
The Ebola virus disease is caused by one of six species of ebolaviruses, four of which are known to cause disease in humans. The viruses belong to the Filoviridae family and are known as filoviruses. The most well-known one is the Zaire ebolavirus.
Current evidence shows that the FDA-approved Ervebo vaccine, which is highly effective against the Zaire ebolavirus, does not provide cross protection against the Sudan ebolavirus, WHO said.
Thus, there are currently no licensed vaccines for the Sudan virus disease, considered a severe, often fatal illness.
WHO has identified six possible candidate vaccines against the Sudan ebolavirus in different stages of development, including the one from JABSOM, with promising data.
Getting to clinical trials
JABSOM, meanwhile, continues working with two private industry partners, Hawaii Biotech of Honolulu and Soligenix Inc., a New Jersey-based biopharmaceutical company, to develop the vaccines and bring them to market.
The vaccine candidates also have gotten the attention of the Biomedical Advanced Research and Development Authority, or BARDA, an arm of the U.S. Department of Health and Human Services that invests in medical countermeasures against emerging infectious diseases.
BARDA recently invited Soliginex to submit a proposal for the development of its SuVax for the Sudan ebolavirus and MarVax for the Marburg marbugvirus, also a filovirus, which has no approved vaccine.
Soligenix said this is promising since SuVax demonstrated 100% protection in nonhuman primates four weeks after vaccination with a three-dose series.
JABSOM’s vaccines are shelf stable because of the lyophilization — or process of freeze-drying — the antigens within them, enabling them to remain viable at temperatures as high as 104 degrees Fahrenheit for up to 12 weeks.
The shelf stable vaccines also come in a single vial, making them easy to transport and store under challenging conditions.
The proposal, if selected, could result in a multiyear, multimillion-dollar contract to develop the vaccines and take them to Phase 1 clinical studies.
Lehrer said he is hopeful, but there is no guarantee the invitation will result in a contract.
Another COVID vaccine
Lehrer’s lab also has developed a vaccine against COVID-19, using the same platform, which was able to move from conceptualization to being tested in monkeys in just under a year.
The vaccine is a recombinant subunit protein vaccine similar to Novavax, said Lehrer. But like the Ebola vaccines, it does not need to be stored at cold temperatures.
Lehrer said his vaccine also uses an adjuvant that can be thermostabilized, and which would be more cost- effective in larger quantities during the manufacturing process. An adjuvant is an ingredient added to some vaccines — like spice added to a recipe, he said — to help boost immune response.
COVID is not going to go away any time soon, he said, and having a diverse range of vaccination options in our arsenal is important.
“We will have to have boosters for awhile to come,” he said. “That is pretty much for sure.”
Soligenix has named the COVID vaccine CiVax, saying it has demonstrated broad responses as both a vaccine and booster across several variants, including the omicron variants.
The vaccine demonstrated a long-lasting and broad neutralizing antibody response in macaques against several variants of concern, including beta, gamma and delta at least three months after the final boost, with results published in a study last year.
“I would say every doctor’s office, every pharmacy should have a small box of these vials sitting somewhere,” said Lehrer. “Because we know the interest is waxing and waning and we cannot just say ‘Oh, now we need it,’ and you produce a lot of it and then three months later all of that product has expired. Whereas here, we have something where the investment is going to last for awhile and you can distribute it so that everyone has it.”
The potential for the technology to help developing countries has been acknowledged by the nonprofit International Vaccine Institute.
Dr. Jerome Kim, director general of the institute, said the platform means potentially avoiding the need for refrigerated or frozen storage and distribution.
“The encouraging development of a broadly neutralizing and efficacious subunit vaccine specifically for SARS-CoV-2, including the variants of concern, using the same heat stable technology platform offers greater promise for achieving worldwide vaccination in the current pandemic,” he said in a Soligenix news release.
Lehrer said the team is in discussions with CEPI, the Coalition for Epidemic Preparedness Innovations, about how the platform could be used to respond to outbreaks.
The filovirus vaccines also have been tested as bivalent and trivalent formulas that combine the Sudan and Marburg viruses as well as the pair with the Zaire ebolavirus.
The trivalent vaccine potentially could be useful for health care workers seeking protection from all three viruses while working in the field, he said.
