Stacy Erholtz, like many, has been inoculated with the measles vaccine, except she received a dose big — enough that it could have served 10 million people. No, this isn’t a precaution against the disease as more measles outbreaks become apparent, but it is actually part of an experimental trial to use the vaccine to fight cancer.

Photo credit: Shuttestock

Photo credit: Shuttestock

Mayo Clinic researchers used this form of “virotherapy,” when you infect cancerous cells and kill them with virus while leaving normal cells untouched, to treat multiple myeloma. The idea of using a virus to destroy cancer goes back several decades, but this study is the first to demonstrate its effectiveness in human subjects. A previous study showed the technique working in mice.

Only two people were involved in the clinical trial, receiving one dose of the engineered measles virus, which is toxic to myeloma plasma cells. Afterward, both patients saw a reduction in bone marrow cancer and myeloma protein.

One of these patients, Erholtz, went into full remission and remained cancer-free for nine months before experiencing a small relapse. Erholtz received no other treatment aside from the modified measles virus, but researchers did note that she developed a bad headache during the treatment. She also experienced a fever for a few days.

The second patient didn’t sustain the same results as Erholtz, but the researchers told the Minneapolis Star Tribune that if they had given that patient a stronger dose, they think they would have seen a better outcome. Through specialized imaging, they still found that the virus was attacking the tumors though.

The newspaper noted that a normal vaccine dose contains 10,000 infectious units of the measles virus, which most people’s immune systems are able  fight off. The patients in this trial were first given 1 million infectious units, but the virus wasn’t effective against the cancer cells until they reached 100 billion infectious units.

“This is the first study to establish the feasibility of systemic oncolytic virotherapy for disseminated cancer,” Dr. Stephen a Mayo Clinic hematologist and co-developer of the therapy, said in a statement. “These patients were not responsive to other therapies and had experienced several recurrences of their disease.”

Watch Russell talk about the significance of this technique:

Erholtz told the Star Tribune that she thinks she’ll be cleared as cancer free next month.

“We don’t let the cancer cloud hang over our house, let’s put it that way, or we would have lived in the dark the last 10 years,” Erholtz told the newspaper.

This virotherapy is now being manufactured for larger clinical trial.

The study was published in Mayo Clinic Proceedings.

(H/T: Reddit

Front page image via Shutterstock.