Innovative New Cancer Vaccine Weaponizes The Body’s Memory Of COVID-19 To Mount A “Coordinated, Supercharged Immune Attack”

If you were vaccinated against COVID-19, your immune system remembers the virus. The whole point of vaccines is that this memory gives your body a head start at fighting an infection the next time you come into contact with it. But, a new study asks, why stop there?

The scientists behind a new vaccine platform want to take that prior immunity and use it to tackle an entirely different disease: cancer.  Their platform is called PROTEXI.

“Killers” and “commanders”

“The idea was born out of a problem that has frustrated cancer vaccine researchers for decades,” Dr John Letterio at University Hospitals Rainbow Babies & Children’s Hospital in Ohio told IFLScience.

“Our immune system has two main types of soldiers in the fight against cancer: CD8 ‘killer’ T cells, which directly destroy tumors, and CD4 ‘helper’ T cells, which act like commanders that tell the killers where to go and keep them energized for the fight.”

 

Other cancer vaccines in the works, said Letterio, bypass the commanders and go straight for the killers. That often means the killers can’t respond as strongly, but it’s a necessary trade-off because identifying cancer-specific commanders is difficult and expensive.

“Then it dawned on us: what if we didn’t need to find new commanders at all? What if we could use commanders that are already on standby in almost every person on the planet, specifically, the immune memory left behind by COVID-19 vaccination or infection?”

Something that has “never really been achievable” before

Most people who have lived through this pandemic have been exposed to SARS-CoV-2 in some way, whether that’s through vaccination or actually catching the virus.

Both routes lead to the generation of immune memory. Letterio and his team told IFLScience they believe their cancer vaccine can capitalize on either type of immunity.

The massive investment in understanding the COVID spike protein and the immunity it generates has given us a tool we can now redirect for a completely different purpose

John Letterio

“The COVID spike protein fragments we use in PROTEXI are recognized by CD4 helper T cells regardless of whether a person built that immunity through vaccination or through surviving a natural infection. What matters is that the memory T cells exist and are functional, which they are in both cases.”

“Given that the vast majority of the global population has now been exposed to the spike protein either through vaccination or infection, this means PROTEXI has the potential to work for an extraordinarily broad population of cancer patients.”

“This is something that has never really been achievable with cancer vaccines before.”

“A coordinated, supercharged immune attack”

To come back to the military analogy, PROTEXI makes use of each patient’s own internal immunity bootcamp.

“We use a patient’s own dendritic cells, which are a type of immune cell that teaches your immune system what to fight; it is a type of immune ‘training cell’. We expand those dendritic cells in the lab and load them with two things at once: fragments of tumor proteins to teach the killers what to hunt, and fragments of the COVID spike protein to summon the ready-made commanders,” Letterio said.

“The result is a coordinated, supercharged immune attack on the tumor.”