In 2013 EPJ D published a paper [1] in which is proposed an experiment that, if it confirms the prediction exposed in the paper, ultimately means a confirmation of the existence of fermions that make up the quantum vacuum. Here is shown a calculation of the value of the electric charge of these fermions. The value achieved for the charge e0 is 5.06532×10− 45 C. From this value of e0, together with the fundamental constants KO, c, ħ, α = 1/137, and the Bohr’s radius, the electric charge of the proton is calculated, achieving the value e = 1.6026×10− 19 C, which is very close to the experimental e = 1.60218×10− 19 C. The calculations from which those results were obtained are exposed here, and in the Conclusion at the end of the paper is shown that the result of such calculations cannot be mere coincidence. From different possibilities to modify the vacuum, if from an experiment be obtained a value close to 5×10− 45 C, the existence of such fermions will be definitively confirmed.