HEALTH OF STOCK.

Hauraki Plains Gazette, Volume XXXVI, Issue 4825, 4 May 1925, Page 1

HEALTH OF STOCK.

COMBATTING TUBERCULOSIS. VACCINATION MAY BE REMEDY. For more than twenty years a French investigator and scientist, Professor Calmette by name, has been conducting experiments on tuberculosis, seeking to find a means of inoculation which will prevent animal life from taking the disease. Professor Calmette now states that he lias "at last succeeded hi giving young animals free from pre-existing tubercle a true immunity against natural or artificial contact with tuberculosis.”

Putting it mildly, this is interesting information, for tuberculosis takes its toll of lives, both in the kingdom of our domesticated animals and within our own sphere of human-kind, unrelentingly and unceasingly.

The methods which Professor Calmette has employed in order to produce this so-called serum are intricate and distinctly scientific ; they are also laborious, and have required many years of time. But the co-called serum is now produced, and it can be increased in amount comparatively rapidly. It is called BCG.

Outstanding features of this experiment include : "Single inoculations of living bacilli into the tissue of the dewlap of young calves createjs an immunity that will resist perfectly the introduction into the calf of virulent bovine bacilli for as long as eighteen months. Although this latter dose of virulent germs is fatal to control. animals (used in checking the experiment) within six to eight weeks from acute tuberculosis, .it never in any way disturbs the health of the vaccinated calves nor gives rise to a single tuberculosis focus. “In general the immunity set up by BCG’ tends to fade in calves towards the end of the second year.” At the expiration of that time it becomes necessary to vaccinate again with BCG. The value of BCG lies in the fact that it may be r used in herds where the tuberculin test has been applied and where reactors have been found. Calves from cows affected with tuberculosis or calves exposed to tuberculosis, may be vaccinated with BCG at five or six days of age, and, if vaccinated again when the BCG has lost its power, at the end of one year or possibly eighteen months they can be carried through their life unaffected by tuberculosis. In a period of several years, perhaps ten, perhaps more, an entire country might be freed from tuberculosis, providing vaccination had been general to all animals exposed to the disease. It is also valuable in that calves from great mothers which may have become tubercular can be saved, and the breeding worth of the great animals, though otherwise lost, is saved to carry on in breeding work.

ECG is effective only in subjects, be they animal, or human ,which are entirely tree from tuberculosis, it does not cure tlie diabase once it has established itself within a body. Professor Calmette and his associates have carried on this vaccinatio'i work in sections of France. ■‘Since 1921 they have vaccinated ail young calves during the-first live days after birth, and have then allowed tlie animals to grow up, exposed to natural contagion—which, in France, includes 40 per cent. p£ mature cattle without changing their residence or the ordinary living conditions of the herds to which they belong. They have repeated vaccination on the calves yearly. What they have aimed to dp is, within five years, to rid previously infected farms of tubei'ieulosis, by gradually doing away with the nonvaccinated adult cattle and keeping only the vaccinated ones, as these, through the natural increase of birth, would, replenish the herds. Up to May, 1924, they had vaccinated in the manner described 127 young calves, all of which remained in perfect health” They state that vaccination ; and annuaul revaccination are absolutely harmless, i

It required thirteen years, bf cultivation, through 230 generations, to •acquire BCG, and yet the experiments nded to be reaffirmed by other scientists and investigators. 7t must be done with material supplied by Professor- Calmette, for the saving of time involved. Certain it is, however, that the investigational work should be carried into all lands and all countries.

The hope is that Professor Calmette’s BCG will be given a thorough and exhaustive trial on cattle. While some work has been done with human infants, it fe not sufficient to warrant any definite conclusions to be drawn, though it should be stated tn at it h'as proved, in the few cases- applied, .-harmless and successful. —Jersey Bulletin.