Currently, so-called “oncolytic viruses” such as herpes are used to treat some types of cancer because of their ability to kill cancer cells. But these therapies are not effective with some tumors and their use poses safety concerns, especially in immunosuppressed patients, underscoring the need for safer alternatives, Penaloza-MacMaster said.
In addition to helping clear the tumors, the therapy also helped prevent future cancer in these mice. Healthy mice that were first treated with the LCMV therapy were more resistant to developing tumors later in life.
This phenomenon might be explained by a poorly understood biological process known as “trained immunity.” Trained immunity occurs when a previous infection enhances the immune system’s ability to respond to different diseases in the future. For example, studies have shown that children who received the tuberculosis (TB) vaccine exhibit improved protection against other microorganisms, not just TB. This differs from the typical vaccine response, such as with the SARS-CoV-2 vaccine, which primarily protects against this specific virus.