Biotech Startup Codagenix Plans Human Trials for COVID-19 Vaccine
The 11-person team at Codagenix may be tiny, but it has big plans for the company’s new COVID-19 vaccine. The Long Island-based team has developed a vaccine made from a live version of the COVID-19 virus that has been engineered to slow virus replication. Following promising results from a pilot study in hamsters, they are now planning human trials.
“Our vaccine is a single dose intranasal vaccine made with a live attenuated version of the virus,” J. Robert Coleman, Ph.D., MBA, co-founder and chief executive officer of Codagenix, told BioSpace. “Live viruses have a broader and more durable immune response.”
The World Health Organization has cataloged 169 candidate vaccines for COVID-19. The vast majority of these use dead virus, genetic material from the virus or components of the virus, such as the spike protein. Only Codagenix and two other developers have used a live attenuated (i.e., weakened) version of the virus.
The bad rap and the truth about live virus vaccines
Live virus vaccines are made by modifying a virus in a laboratory to make it weaker. In rare cases, natural mutations can cause viruses to revert to their original virulence. As a result, live virus vaccines often get a bit of a bad rap due to the potential for reversion.
Coleman explained that the negative perception of live virus vaccines also stems from how vaccines were historically made.
“First generation vaccines relied on only a handful of changes, so the virus could revert. We use hundreds of changes and can show extreme genetic stability,” Coleman said. “We think this is an added benefit. Our approach relies on ‘death by one thousand cuts’, meaning that viruses are unable to revert.”
Despite their bad rap, live virus vaccines tend to be stronger and more long-lasting than those made from dead viruses. As Coleman pointed out, live virus vaccines have been effective at eradicating diseases. The measles vaccine, for example, is a live-attenuated vaccine.
When it comes to COVID-19 vaccines, ease of access and scalability are key
The Codagenix COVID-19 vaccine also has a number of additional benefits over other candidate vaccines out there.
“The intranasal dropper does not require a sterile needle or a skilled healthcare provider to administer it,” Coleman said.
The ease of administration means that more people would potentially have access to the vaccine.
Another important aspect of the Codagenix vaccine is its scalability. Their vaccine can achieve immune responses at much lower doses of antigen than are typically required (a technique known as "dose-sparing").
“All other companies are capped at how many doses they can make,” Coleman said. In contrast, the Codagenix team can potentially make “hundreds of millions of doses in six weeks due to the number of doses per unit volume.”
Pilot studies prove promising
So far, the Codagenix team has tested their vaccine in hamsters. As, Coleman explained, “hamsters are one of the best small animal models for COVID-19 vaccine testing.”
The potential utility of hamsters in coronavirus vaccine research was first stumbled upon 15 years ago when scientists discovered that hamsters can be infected with the virus that causes severe acute respiratory syndrome (SARS). However, the hamsters’ symptoms were subtle and the model didn’t receive much attention. Once the COVID-19 pandemic began, however, hamsters began to receive more attention for their potential utility in developing vaccines for SARS-CoV-2 (the virus responsible for COVID-19).
A research study published in the journal Clinical Infectious Diseases on March 26, 2020 further demonstrated the usefulness of hamsters in SARS-CoV-2 vaccine development. The scientists found that hamsters infected with SARS-CoV-2 developed rapid breathing, lethargy, ruffled fur, hunched posture and weight loss. Further, the researchers found SARS-CoV-2 in the hamsters’ lungs and intestines. These symptoms closely resemble the symptoms of SARS-CoV-2 infection in humans.
Hamster models also have benefits over mouse models. For example, many mouse models used for COVID-19 research involve genetically modified mice, making them less likely to mimic natural biological conditions.
Though the Codagenix vaccine has proven effective in animals, it must still undergo a number of human testing phases before it can be brought to market.
In the immediate future, the Codagenix team has plans for Phase I human clinical trials. To do this, they have teamed up with Open Orphan PLC, a CRO pharmaceutical services company based in Dublin. The Phase I trial, which will occur in London, will evaluate the safety of the vaccine and will include about 50 young adult volunteers.
If the Phase I trial is successful, the vaccine will move on to Phase II and III trials in India. While Phase I trials usually involve a relatively small number of participants and aim to determine the appropriate dosage of a candidate drug or vaccine, Phase II trials usually include hundreds of participants and look at the safety of the treatment over a longer period of time. In Phase III trials, which typically include thousands of study participants, some participants would receive the vaccine while others would receive a placebo. The aim of these trials is to look at the vaccine’s long-term efficacy and safety.
The Codagenix team also says that they might be interested in human-challenge trials. Human-challenge trials typically involve inoculating healthy volunteers, allowing time for an immune system response to develop, and infecting the volunteers with COVID-19. This is different from traditional clinical trials, which inoculate participants and then allow them to go about their normal lives, where they may or may not be exposed to COVID-19.
Given that there is no known treatment that can reliably and effectively stop COVID-19, the use of human-challenge trials in COVID-19 vaccine development is controversial. However, human challenge trials are often able to reduce the amount of time and the number of study volunteers needed to determine the effectiveness of a vaccine. In the case of a rapidly spreading pandemic like COVID-19, the value of rapidly bringing a vaccine candidate to market may outweigh the risks.