MAMMITIS VACCINE.

Hauraki Plains Gazette, Volume XXXVI, Issue 4900, 9 November 1925, Page 4

MAMMITIS VACCINE.

DISCUSSION ON. REPORT. VIEWS! OF A BACTERIOLOGIST. “I am convinced,” said Mr J. G. Smith, bacteriologist to the ’Waikato Hospital, at Hamilton, “that the persistent use of vaccine is the only means of combating contagious manimitis.” Referring to the’interim report of the Department of Agriculture Mr Smith pointed out the difference between artificial infection —which the department makes the basis of a test —and natural infection, as found amongst sq many dairy herds to-day. In .tjie following article Mr Smith shows how great is the difference between artificial and natural infection, not only in respect to mammitis but in all scientific treatment of ailments and disorders of any kind. As the interim report issued by the Agricultural Department regarding the efficacy of the vaccine with which dairy cows are being inoculated with the object of making' them immune from contagious mammitis infection was inclined to suggest that the vaccine was of no use, Mr J. G. Smith, bacteriologist to the Waikato Hospital at Hamilton, who prepared the vaccine, states that it was; only fair to anyone who had taken an interest in its use to lay a few facts before the farmers. As hej pointed out to the officers of the Agricultural Department, the experiments carried out by them were of little value, as they demonstrated only one point—that the use of, the vaccine would nbt protect against artificial infection, which was vastly different from natural, infection. The vaccine for mammitis was prepared on similar lines to anti-ty-phoid vaccine, the value of which-was undoubted. Yet a person who was inoculated against typhoid fever could not swallow the germs and hope to escape infection. He had consulted the highest authorities, who agreed on that point. He quoted from Kolmer’s “Infection Immunity and Specific Therapy,” the greatest .work published on the subject, in which is stated: “Duration and. degree of typhoid immunity : it should be emphasised that immunity following typhoid, inoculation is not absolute, and an immunised person cannot afford to neglect ordinary precautions against infection. A lowered state of body health or a large dose of infectious material may at any time result in infection.” No one could claim that injecting infected material up the teat canal of a. cow, as Was done by the Department, could be considered, an ordinary precaution. It was "a well-known fact that some animals were naturally immune, and would never contract contagious mammitis by ordinary means. ; the control cows of the Department’s .tests might easily be in- this category, as immunity was ah unknown factor, and. differed in every, individual, whether produced by inoculation or by natural means. Therefore, results obtained 'over a few cows artificially infected were not sufficient to undermine the confidence of people who believed in the treatment of contagious mammitis by vaccines. Ais far as his own experiments were concerned Mr Smith states that these were conducted over several hundreds of cows and herds that were inocu-

lated three years ago, and were badly infected at the time ; these cows were still free from the disease. He had demonstrated in the laboratory the effect of the blood serum of an inoculated cow upon the germ of the disease, and produced a similar effect as that observed when the blood serum from a patient inoculated against typhoid was tested with the typhoid bacillus. Regarding .the use of vaccines for contagious mammitis In other countries,, in 1922 the director pf the Australian Commonwealth Serum Laboratories, Dr. Penfold, a noted scientist, and late assistant director of the Lister Institute; London, issued a circular to veterinary surgeons advocating the use of vaccine for contagious mammitis. One point in the Agricultural. Department’s report which Mr Smith wishes to draw attention to was the statement concerning the danger in “resting under a false security.” Where the vaccine was used the fanners* were expressly told that they must not neglect ordinary precautions. A vaccine would have an effect only upon the particular infecting organism from which the, vaccine was prepared. He commenced experiments on cows with vaccine prepared from organisms isolated from human beings, and carried on the work of contagious mammitiis vaccine through representations from farmers whose cows had had great relief from the vacteine, and he was more than ever convinced that the persistent use of vaccine was the only means of combating contagious mammitis, which was the worst form of udder trouble.