The claim: Mayo Clinic researchers employing “virotherapy”—or virus-based treatment—completely eradicated a 49-year-old woman’s blood cancer using an extremely heavy dose of the measles vaccine (enough to vaccinate 100 million people), according to a newly released report in the journal Mayo Clinic Proceedings.

The research: The study team injected two cancer patients with “the highest possible dose” of an engineered measles virus. (Past research had shown the virus was capable of killing myeloma-infected plasma cells while sparing normal tissue.) Both patients responded to the treatment and showed reductions in bone marrow cancer and myeloma protein. One of the patients, Stacy Erholtz, experienced complete remission and has been cancer-free for 6 months.

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What it means: This is the first study to show that this type of virotherapy may be effective when it comes to some types of cancers, says study coauthor Stephen Russell, MD, PhD, a Mayo Clinic hematologist and co-developer of the treatment. “Viruses naturally destroy tissue,” Russell explains. And the measles virus appears to cause cancer cells to group together and “explode,” which not only destroys them but also helps alert the patient’s immune system to their presence, says one of Russell’s coauthors on the study, Angela Dispenzieri, MD. While the second myeloma patient did not experience such a dramatic recovery, the virotherapy was still effective in targeting and treating sites of her tumor growth, the Mayo researchers say.

The bottom line: The two women included in the study were chosen because their cancer had failed to respond to other treatments, and so they were out of options, the study authors say. Also, neither of the women had much previous exposure to measles, which means they had few antibodies to the virus. While a lot more work has to be done to develop the treatment for other cancer sufferers, Russell says the ultimate goal for this therapy is “a single-shot cure for cancer.”

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The article was written by Markham Heid and originally appeared on Prevention.com

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