Researchers at the Ontario Veterinary College (OVC) and McMaster University’s Immunology Research Centre have joined together to treat breast cancer in cats using new vaccines designed to boost the immune system and kill tumor cells without harming healthy tissue, according to a University of Guelph release. The trial may lead to better treatment of breast cancer in animals and people. Maci, the first patient in the trial receives a vaccine.

Breast cancer occurs naturally in cats and is similar in many ways to the disease in humans. Trials may answer important questions about the disease that studies involving artificially induced cancer in laboratory animals cannot.

Cats participating in the study receive two vaccines, one prior to surgery and the other after. Each vaccine contains a virus modified to carry three genes associated with breast cancer. The first injection is a nonreplicating adenovirus intended to trigger an anti-tumor response, according to the release. The second is an intravenous infusion about a month after surgery. It delivers an oncolytic Maraba virus that replicates only in tumor cells, targeting and killing them