Vaccines for microbic diseases not due primarily to toxins tend to be second rate: useful, but far short of absolute in protective value. Venereal diseases fall into this group. So far we have no vaccines against them at all; and as we will see, it is unlikely that vaccines can ever have the degree of effectiveness against them that they have against virus diseases or those due primarily to toxins (a group which includes tetanus as well as diphtheria). Sanitation is simply not available for control of venereal diseases: their agents pass directly from person to person, and are not in the environment long enough to give us any chance of scotching them there.

A third means for control of infectious disease is effective treatment, which, in the absence of the other two, has been the basis of modem efforts to control YD. Treatment has worked well for control of the non-venereal treponematoses, but it obviously has not worked with YD. This is true despite the fact that gonorrhea has been, and syphilis still is, easily curable.

This is still true of gonorrhea as well as of syphilis, in spite of the recalcitrance of the gonococcus. If a given dose of penicillin doesn't work, a larger dose usually will; and in the individual case there are always alternative drugs. emphasize this point to make it clear that failure of control is not simply failure of treatment. Anyone who has any of the venereal diseases can get rid of it. Doing so at the earliest moment, before the infection is passed on to others, is an essential ingredient of control. If we could find a way to get every person with early infectious VD into a treatment center before he or she could have passed the disease on to somebody else, we would have the problem cleaned up just like that. But it was, perhaps, precisely because we thought this would be easy, back in the late 1940s that we failed.

Let take one more look at history. The story of attempts to control venereal diseases can begin only as their venereal nature came to be recognized; and as we have seen, this recognition was a gradual, stumbling, two steps forward and one step backward process down to modem times, forming one strand of the tangled web of ideas about contagion. As the particular web of contagion became disentangled, which happened only at the beginning of the twentieth century, we were able to start effective machinery for control of diseases other than VD; but the VD problem seemed to remain in a separate snarl.