We would like to report here on our clinical observations in 212 subjects, vaccinated in our Center since the start of the Coronavirus disease-2019 (COVID-19) pandemic, with the mumps-measles-rubeola (MMR) vaccine and of whom thirty-two have presented COVID-19, all with a remarkably mild course.In the light of the COVID-19 pandemic, observing the highly contagious and virulent nature of the virus, new to mankind and for which no actual treatment nor vaccination exists, we have been searching for methods to enhance innate immunity. Moreover, the pandemic started in our country just after a rise in measles cases had motivated the Ministry of Health to recommend measles re-vaccination. Aware of the existence of trained immunity we decided to apply this concept and from March 2020 onward recommend MMR vaccination, but with extra emphasis among family members of COVID-19 cases. In June 2020 the American Society for Microbiology (AMS) speculated in a press-release that “the MMR vaccine could serve as a preventive measure to dampen …. COVID-19 infection.”