Vector platform technology used in COVID-19 vaccine candidate


By: Julia Malacoff

With the first COVID-19 vaccines beginning to be administered, many across the globe are eagerly watching and waiting, wondering when it will be their turn to receive a vaccination. But due to supply chain, storage and other scalability limitations, not everyone who wants to be vaccinated in the next few months will be able to do so.

That’s one of the reasons it’s so important for researchers to continue developing additional COVID-19 vaccine candidates, even after the first few have been approved for human use.

One such vaccine contender is making its way through its Phase 1 clinical trial, utilizing a vector platform developed by Andrea Amalfitano, dean of the College of Osteopathic Medicine at Michigan State University.

“I've always wanted to use genetic technology to treat human disease,” Amalfitano said. “That desire developed into research that basically took a virus that causes the common cold and turned it into a potential therapeutic medicine.”

The technology Amalfitano referred to is a deconstructed adenovirus. With the genetic information that causes a cold removed, researchers are left with a virus that can be used as a genetic delivery platform, also known as a vector platform. Though it was originally designed to improve the safety of gene therapy in general, Amalfitano and his colleagues discovered the vector can be used in a “plug-and-play” manner to treat a variety of diseases: infectious diseases, genetic diseases and cancer. It can also be repeatedly administered to boost beneficial immune responses.

Until now, the vector was primarily being used in clinical trials with thousands of pancreatic, breast, gastric and colon cancer patients. When COVID-19 happened, the team at ImmunityBio, the immunotherapy company working with Amalfitano’s technology, quickly switched gears to create an adenovirus-based COVID-19 vaccine.

That’s significant for a couple of reasons. First, this specific vector platform has a track record of safety in humans already, which may stand out amongst other virus-based vaccines, Amalfitano noted.

Second, adenovirus-based vaccines are common and have a decades-long history of use. For example, since the 1960s, United States military recruits have been receiving adenovirus-based vaccine tablets during bootcamp to prevent adenovirus infections.

In contrast, the Pfizer/BioNTech and Moderna vaccines are mRNA-based vaccines.

”RNA-based vaccines have never been approved as a human vaccine, to date,” Amalfitano said.

That certainly doesn't mean they should be dismissed, but adenovirus-based vaccines may have an advantage when it comes to manufacturing enough doses to vaccinate larger numbers of people. In fact, when creating the vector platform, Amalfitano ensured it was constructed in a way that would be easier to scale up. ImmunityBio is also exploring delivering the vaccine orally and by inhalation, which could facilitate getting the vaccine to more people rapidly.


With Phase 1 human trials currently underway, Phase 2 / 3 trials are now being designed. If all goes according to plan, that could mean the vaccine is available sometime in spring 2021, Amalfitano said.

More than anything, the quick move from cancer vaccine applications to a COVID-19-specific application highlights the importance and versatility of this kind of vector platform technology.

“Investment in this type of research can really go above and beyond what the inventor has considered,” Amalfitano said. “Sometimes, you can't even imagine the scope of how what you invent in the laboratory might be deployed.”