[ Pobierz całość w formacie PDF ]

600 M. SCHWARTZ
The concept of acquired immunity dates from ancient cholera and anthrax, i.e. create an attenuated form of the
times. Indeed, Thucydides reported that those who were microbe. In fact, as he was to realize later, most of the virus
cured of the plague no longer ran the risk of falling victim to was presumably killed in his preparations. Thus, rather
the disease. The ®rst vaccine was developed by the English unknowingly, he opened the way for the second class of
physician, Edward Jenner, who, at the end of the 18th vaccines, besides attenuated live micro-organisms, and
century discovered that human beings could be protected consisting in inactivated micro-organisms, which would
against smallpox by inoculation of the similar but benign themselves later lead to subunit vaccines.
disease, called `cowpox' in English, and `vaccine' in French. The story of the vaccination against rabies is well known.
Although of crucial importance, since it lead to complete So well known, in fact, that for many this was the sole
eradication of smallpox in 1979, this empirical discovery accomplishment of Pasteur!
could not be generalized to other diseases. The success of the vaccination of Joseph Meister on July 6,
It is often said that Jenner discovered vaccination, and 1885 and of the shepherd boy Jean-Baptiste Jupille in
Pasteur invented vaccines. October of that same year, followed by hundreds of other
Pasteur's fundamental discovery in this ®eld dates back to bite-victims from throughout the world, brought glory to
1879 and concerned the disease known as fowl cholera, Pasteur and opened up the era of preventive medicine. On
which was rampant in chicken coops at that time. the heels of this success, the `Academie des Sciences'
The disease was due to bacteria which today bear the launched an international fund-raising campaign to build the
name `Pasteurella'. When inoculated into a chicken, several Institut Pasteur. It was there that Louis Pasteur lived out his
drops of a culture of these bacteria were suf®cient to kill the last years, it is there that he lies in his ®nal resting place, and
animal. But Pasteur noted, partly by chance it would seem, it is there that, for over a century now, the work that he
that chicken inoculated with an old culture not only did not began is being pursued by his followers.
die but were protected against a later inoculation with a Louis Pasteur has left us many messages, which I have
virulent culture. The principle of vaccination with attenu- tried to brie¯y summarize in this presentation. In ending,
ated pathogens was thus discovered. I would like to quote him once more, and leave you with a
From then on, Pasteur repeatedly applied this principle to last message, which seemed to me of particular relevance at a
other diseases. His ®rst great success both at a scienti®c time when we are confronted with such terrifying emerging
1evel and in terms of public opinion ± today we would refer infectious diseases, as are AIDS and BSE. This quote is
to it as a `mass media happening' ± was the vaccination from an article published in 1881, the year of the vaccine
against anthrax. The famous public experiment held in against anthrax, when Pasteur had just found that virulence
Pouilly le-Fort in 1881, during the course of which is not a ®xed trait of micro-organisms. Virulence could be
24 vaccinated sheep survived an injection of the anthrax weakened to create attenuated strains, why could it not be
bacillus, while 24 nonvaccinated sheep died, had extra- increased under other conditions? Here is the quotation:
ordinary repercussions, convincing a large portion of public And so it is that virulence appears to us in a new light,
opinion of the validity of Pasteur's work. rather disquieting for humanity, unless nature in its
The few remaining sceptics rallied around Pasteur for his evolution during centuries of the past already encountered
®nal victory, that of human vaccination against rabies. The all possible occasions of creating virulent or contagious
problem was complicated from the very outset, for the rabies diseases, something which is very unlikely.
microbe was invisible ± we now know that it is a virus rather What makes a micro-organism harmless for a human being or
than a bacterium ± and could not multiply in any culture any given animal? It is a micro-organism which cannot grow
medium. But the stakes were high, for although the disease in our body or in the body of this animal; but nothing proves
was relatively rare in France, it had always fascinated the that provided this micro-organism were to penetrate one of
popular imagination, conjuring up fear and mystery. For the thousands of species of Creation, it might not invade it
Pasteur, conquering rabies would consolidate the ®nal and make it ill. Its virulence, then reinforced by successive
victory of his theories. passages through members of this species, could become able to
Even though he could not see or cultivate the microbe, infect some animal of large size, man or certain domestic
Pasteur knew that it had to be there. It had to be in the animals. In this way new virulences or contagions could be
nervous system, recognized as its target. As a replacement created. (Pasteur 1881)
for in vitro cultivation, Pasteur transmitted the infectious
agent from animal to animal, by intracerebral inoculation.
REFERENCES
He adapted the disease to the rabbit, and then undertook to
Â
Liebig, J. (1839) Sur les phenomenes de la fermentation et de la
attenuate the invisible microbe, which he did by dessication
Â
putrefaction, et sur les causes qui les provoquent. Annales de Chimie
of the spinal cord of infected animals. In doing so, he
et de Physique. 2e Serie LXXI, 178.
thought, at ®rst, that he was doing the same as with chicken
ã 2001 The Society for Applied Microbiology, Journal of Applied Microbiology, 91, 597±601
THE LIFE AND WORKS OF LOUIS PASTEUR 601
Á
Lister, J. (1893) In Jubile de Louis Pasteur, Paris, 1893. pp. 16±17. Paris: Pasteur, L. (1862) Note remise au Ministere de l'Instruction publique et des
Gauthier-Villars et Fils. cultes, sur sa demande, Avril 1862. In L'oeuvre de Pasteur, T.VII, p. 3.
Â
Pasteur, L. (1857) Memoire sur la fermentation appelee lactique. Pasteur, L. (1879) Examen critique d'un eÂcrit posthume de Claude Bernard
 Â
In Memoires de 1a Societedes Science, de l¢Agriculture et des arts de sur la fermentation. Paris: Gauthier-Villars.
    Â
Lille, seance du 3 aout 1857, 2e Serie, V, pp. 13±26. Pasteur, L. (1881) De l¢attenuation des virus et de leur retour a la
Á Â
Pasteur, L. (1859) Lettre de Pasteur a Pouchet, Paris 28 fevrier. virulence (avec la collaboration de MM.Chamberland et Roux).
Archives du Museum d'Histoires Naturelles de Rouen, no. 1023 du Comptes rendus de l¢AcadeÂmie des Sciences, SeÂance du 28 Fevrier XCII,
catalogue de la Bibliotheque. 429±435.
ã 2001 The Society for Applied Microbiology, Journal of Applied Microbiology, 91, 597±601 [ Pobierz caÅ‚ość w formacie PDF ]