Get MMR vaccine shot now to protect against severe COVID-19

In yet another hope to fight several COVID-19 symptoms, administering the MMR (measles, mumps, rubella) vaccine could serve as a preventive measure to dampen septic inflammation associated with the virus infection, say researchers.

Vaccination with MMR in immune-competent individuals has no contraindications and may be especially effective for health care workers who can easily be exposed to COVID-19, said experts in a paper published in mBio, a journal of the American Society for Microbiology.

"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 Paul Fidel, Associate Dean for Research at Louisiana State University Health School of Dentistry.

"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," Fidel added.

Mounting evidence demonstrates that live attenuated vaccines provide non-specific protection against lethal infections unrelated to the target pathogen of the vaccine by inducing trained nonspecific 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 the laboratory of Dr Mairi Noverr, Professor of Microbiology and Immunology at Tulane University School of Medicine in New Orleans, in collaboration with Dr. Fidel, vaccination with a live attenuated fungal strain-induced trained innate protection against lethal polymicrobial sepsis.

Mortality in COVID-19 cases is strongly associated with progressive lung inflammation and eventual sepsis.

Recent events provide support for the researchers' hypothesis.

The milder symptoms seen in the 955 sailors on the USS Roosevelt who tested positive for COVID-19 (only one hospitalization) may have been a consequence of the fact that the MMR vaccinations are given to all U.S. Navy recruits.

In addition, epidemiological data suggest a correlation between people in geographical locations who routinely receive the MMR vaccine and reduced COVID-19 death rates.

"COVID-19 has not had a big impact on children, and the researchers hypothesize that one reason children are protected against viral infections that induce sepsis is their more recent and more frequent exposures to live attenuated vaccines that can also induce the trained suppressive MDSCs that limit inflammation and sepsis," the authors wrote.

The researchers propose a clinical trial to test whether the MMR vaccine can protect against COVID-19 and, in the meantime, suggest that all adults, especially health care workers and individuals in nursing homes get the MMR vaccine.