Source: In 1917 Rudolf Steiner foresaw a vaccine that would ‘drive all inclination toward spirituality out of people’s souls’

The similar, more general conclusion is to be found in BT of G.I.G:

“But from all the experiments conducted by this sage, it became evident that the most harmful vibrations for contemporary terrestrial three-brained beings are the ones produced in them by what they call ‘medical remedies.’