4
MANUAL OF VACCINATION FOR THE
deadly disease known as rabies in the dog or hydrophobia in man, can, by
being passed through a succession of monkeys, be made harmless to dogs.
As stated in paragraph 2, cow-pox in the cow was in all probability first
produced by the cow being milked by a human being suffering from small-
pox, the virus being thus accidentally introduced into the udder or teats of the
cow. Healthy milkers whose hands became infected from contact with the
teats of such a cow, could then carry the virus to other cows.
Another objection urged against vaccination is that it is dangerous to
life.
The Royal Commission on vaccination calculated that in not more than 1
in 14,000 vaccinations was serious illness produced, and that of such cases
more than half were preventible. That is to say the danger of vaccination
is much less than the danger of giving an anæsthetic such as chloroform.
A small-pox epidemic among 1,400 unvaccinated people would produce
probably more than 700 deaths. The risk from vaccination is therefore so
small that it can hardly be counted as a valid argument, against its use.
It has also been said that such diseases as syphilis, tubercle, and leprosy
are transmitted by vaccination. It is known that syphilis can be so trans-
mitted, though not easily. There is as yet no proof that tubercle or leprosy
has ever been so transmitted. Such transmission cannot occur when lymph
is taken from healthy children of healthy stock, and is of course impossible
when calf lymph is used.
Conclusions reached by the Royal Commission on Vaccination.
(Report of
18th September 1896.)
8. The following conclusions are the results of some seven years of
investigation, carried out by unbiased men of great intelligence and with
exceptional opportunity for obtaining evidence.
They say: —
(i) That it (vaccination) diminishes the liability to be attacked by
the disease (small-pox).
(ii) That it modifies the character of the disease and renders it (a) less
fatal, and (b) of a milder and less severe type.
(iii) That the protection it affords against attacks of the disease is great-
eat during the years immediately succeeding the operation of vac-
cination. It is impossible to fix with precision the length of this
period of highest protection. Though not in all cases the same,
if a period is to be fixed it might, we think, fairly be said to cover
in general a period of nine or 10 years.
(iv) That after the lapse of the period of highest protective potency, the
efficacy of vaccination to protect against attack rapidly diminishes,
but that it is still considerable in the next quinquennium and possibly
never altogether ceases.
(v) That its power to modify the character of the disease is also greatest
in the period in which its power to protect from attack is greatest,
but that its power thus to modify the disease does not diminish
as rapidly as its protective influence against attack, and its
efficacy during the after periods of life to modify the disease is still
very considerable.
(vi) That revaccination restores the protection which lapse of time has
diminished, but the evidence shows that this protection again dimi-
nishes, and that to ensure the highest degree of protection which
vaccination can give, the operation should be repeated at intervals.
(vii) That the beneficial effects of vaccination are most experienced by
those in whose case it has been most thorough. We think it may
fairly be concluded that when vaccine matter is inserted in three or