MMR (Measles, Mumps, Rubella) Vaccine Can Protect Against Severe COVID-19 Symptoms

Paul Fidel, Jr., Department Chair, Oral and Craniofacial Biology, and Associate Dean for Research, Louisiana State University Health School of Dentistry and Dr. Mairi Noverr Professor of Microbiology & Immunology at Tulane University School of Medicine, have stated that vaccination with MMR in immunocompetent individuals has no contraindications and could be particularly effective for health care workers who are more exposed to COVID-19.

There is growing evidence that live attenuated vaccines provide non-specific protection against lethal infections unrelated to the target pathogen of the vaccine by inducing trained non-specific innate immune cells for improved host responses against subsequent infections. Live attenuated vaccines induce nonspecific effects representing “trained innate immunity” by training leukocyte (immune system cells) precursors in the bone marrow to function more effectively against broader infectious insults.

In their laboratory studies, the researchers found that vaccination with a live attenuated fungal strain-induced trained innate protection against lethal polymicrobial sepsis. The protection was mediated by long-lived myeloid-derived suppressor cells (MDSCs) previously reported inhibiting septic inflammation and mortality in several experimental models. According to the researchers, an MMR vaccine should be able to induce MDSCs that can inhibit or reduce the severe lung inflammation/sepsis associated with COVID-19. The researchers have proposed a clinical trial to test whether the MMR vaccine can protect against COVID-19, although in the meantime, they suggest that all adults, especially health care workers and individuals in nursing homes get the MMR vaccine.

“Live attenuated vaccines seemingly have some nonspecific benefits as well as immunity to the target pathogen. A clinical trial with MMR in high-risk populations may provide a low-risk-high-reward preventive measure in saving lives during the COVID-19 pandemic,” said Dr. Fidel. “While we are conducting the clinical trials, I don’t think it’s going to hurt anybody to have an MMR vaccine that would protect against the measles, mumps, and rubella with this potential added benefit of helping against COVID-19.”