Measles, mumps, and rubella (MMR) vaccination is a “live attenuated” vaccine that can offer health benefits beyond the diseases it aims to prevent. These non-specific effects of some vaccines seem to train the immune system to combat other infections, something called “trained inate immunity”. Dr. Paul Fidel and colleagues at Louisiana State University had discovered that immunization with a live attenuated fungal strain induced trained innate immunity protecting mice from sepsis through myeloid-derived suppressor cells. They wanted to apply this knowledge to the fight against COVID-19 infection. The researchers recently published a report on their efforts to determine if MMR vaccination could help to reduce the severe impacts of COVID-19 in healthcare workers, and if the suppressor cells were involved. Unfortunately, they were unable to show an impact of the MMR vaccine on COVID-19 health status or the suppressor cells due to small sample sizes because most of the participants became vaccinated for COVID-19 shortly after the trial started.
Scientists around the world have been conducting research to understand if existing treatments or medications could reduce the impact of COVID-19. Challenges have been significant, including the lack of funding for clinical trials (outside of those conducted by pharmaceuticals), difficulty in enrolling participants, and evolving COVID variants over time. As Dr. Fidel’s clinical trial illustrated, the vaccine status of participants also impacts research outcomes. The Parsemus Foundation has been proud to support clinical studies of repurposed medicines in the fight against COVID-19 and was a supporter of Dr. Fidel’s work.