Efficient Vaccination.—The clinical activity and bacterio logical purity of the lymph employed for vaccination; the skilful performance of the operation itself ; the making of an adequate number of insertions of lymph over a sufficient area ; the observ ance of strict asepsis, at the time of vaccination and until the vac cination wounds are soundly healed—all these are essential to "effi cient vaccination." Certain principles are generally recognized, and for public vaccinators, whose work comes under government inspection, instructions on these several points are prescribed. The lymph universally employed in Great Britain is glycerinated calf lymph, the use of which has entirely superseded, in public vaccinations, the arm-to-arm method. Glycerinated lymph, under proper conditions, usually retains its potency for many weeks or months; but is liable to become gradually weakened, and even eventually to become inert.
There exists no official definition of what constitutes a "suc cessful vaccination." The standard long ago laid down by the Local Government Board—the production, namely, of a total area of vesiculation of not less than half a square inch, divided among four separate vesicles or groups of vesicles, not less than half an inch from one another—has for the most part proved easily attainable in practice, and should be aimed at in private as in public work.
Alleged Injurious Effects.—In a certain small proportion of cases vaccination has been followed by various inflammatory complications, which are not peculiar to vaccination, but con stitute the danger of any local lesion of the skin, however caused. A few authenticated cases have been recorded in which there was reason to believe that syphilis was conveyed by arm-to-arm vac cination. Tubercle in its various forms and leprosy have also been included in the list of possible complications of vaccination, though without any sufficient proof. The employment of glycer inated lymph obviates these dangers for even if tubercle bacilli or the streptococcus of erysipelas were by chance present in the lymph material when collected, it has been found experi mentally that they do not survive prolonged exposure to the action of a 50% solution of glycerine in water. Leprosy and syphilis are not communicable to the calf. In view of the fre quency of various skin eruptions in infancy; it is to be expected that in a proportion of cases they will appear during the weeks following vaccination. Eczema and impetigo in particular have, post hoc, been attributed to vaccination, but no direct connection has been proved to exist between the operation and the occurrence of these disorders. Of a different order is the post-vaccinal en cephalitis described by Turnbull and McIntosh at the British Med ical Association meeting in July 1928. The condition has been
noticed in some hundreds of cases and manifests itself on the average 10-14 days after vaccination as headache, delirium, pare sis and ultimately coma and death in fatal cases.
Legislation.—Legislation making vaccination compulsory was first introduced in Bavaria (1807), Denmark (I8io), Sweden (1814), Wiirtemburg, Hesse and other German states (1818), Prussia (1835), the United Kingdom (1853), German empire (1874), Rumania (1874), Hungary (1876), Serbia 0880, Aus tria (1886). But in many cases there had been earlier provisions indirectly making it necessary. In the same way, where there is no compulsory law there are government facilities and indirect pressure, apart from the early popularity of vaccination which made it the usual practice. In the United States there is no federal law, but many of the separate states make their own compulsion either directly or indirectly, Massachusetts starting in 1809.
The benefit of vaccination proved itself in the eyes of the world by its apparent success in stamping out small-pox; but there continue to be people, even of the highest competence, who regard this as a fallacious argument—post hoc, ergo propter hoc. In addition they point to the dangers enumerated above as reasons for their opposition to the practice and insist that the diminution of small-pox is due to improved general hygiene and segregation. The cause of "anti-vaccination" has had many followers in England, and their persistence has had important effect in English legislation. Under the provisions of the Vaccination Act 1898, the Vaccination Order (1898) of the Local Government Board and the Vaccination Act 1907, numerous changes in connection with vaccination administration and with the performance of the opera tion were introduced, in addition to the supersession of arm to-arm vaccination, by the use of glycerinated calf lymph. Thus, whereas by the Vaccination Acts of 1867 and 1871 the parent or person having the custody of any child was required to procure its vaccination within three months of birth, this period by the act of 1898 was extended to six months. Again, parents were relieved of any penalty under the compulsory clauses of the Vac cination Acts who afforded proof that they had, within four months of the birth of a child, satisfied a stipendiary magistrate, or two justices in petty sessions, that they conscientiously believed that vaccination would be prejudicial to the health of the child. Moreover, the public vaccinator was now required to visit the homes of children for the purpose of offering vaccination with glycerinated calf lymph, "or such other lymph as may be issued by the Local Government Board." Much good has arisen from the substitution of domiciliary for stational vaccination.