Vaccine for Newcastle Disease
By Canadian Poultry
By Canadian Poultry
Dr. Fred Beaudette, poultry pathologist of the Rutgers University Experiment Station, has announced the development of a live virus vaccine that can be used safely on four to six-week-old chicks to give them a lifetime protection from Newcastle disease. Officials at the station predicted that the vaccine would save the U.S. poultry industry thousands of dollars in the next few years.
Dr. Beaudette said that the vaccine has been field tested on more than 85,000 chicks in New Jersey with excellent results. Mortality from all causes during the three weeks after vaccination has been under 1½ %, or les than 15 dead from each 1,000 chicks vaccinated. Since many of these undoubtedly died from other causes, the mortality attributed to the vaccine is insignificant.
The long awaited vaccine is of the live virus type, which means that it actually produces a mild case of the disease in an inoculated chick, but in most cases this is so slight that its effects cannot be detected.
Dr. Beaudette explained that chicks from parents which have had Newcastle disease inherit an immunity, which lasts about a month after the egg is hatched. The new vaccine can be used on chicks immediately after the inherited immunity has worn off.
Proof of Value Shown
Spectacular proof of the effectiveness of the new discovery was obtained by Dr. Beaudette and his staff in their field tests. On one farm a poultryman had lost 1,794 out of 4,890 chicks from Newcastle – 35% – when he appealed to Dr. Beaudette to vaccinate his later hatches. Of the 1,841 chicks vaccinated, some of which had already contracted the disease, only 62 died, or a little over 3%.
On another farm the loss in 2,775 unvaccinated susceptible chicks was more than 2,400, whereas in 581 chicks vaccinated with the new vaccine, the loss was only four, or less than 1%.
The pathologist warned poultrymen that certain precautions must be taken in using the vaccine. Vaccinated stock can spread the disease to susceptible birds for a period after vaccination, which is thought to be about three weeks. Where successive pens of birds are being brought along, therefore, it is necessary to vaccinate each pen as soon as the birds in it have lost their inherited immunity, or in other words, at about four weeks of age.
Dr. Beaudette produced the new vaccine by collecting a large number of strains of the virus ad screening them to find one that was mild enough to make it safe to use on young stock. When he began his screening he had more than 100 strains of the disease in his laboratory. The strain of virus from which the new vaccine is produced was the mildest of the entire collection.
Early Production Possible
The vaccine will be released by the experiment station to any qualified manufacturer of biological products licensed by the U.S. Bureau of Animal Industry, Dr. Beaudette said. No patent will be taken out on the virus.
How soon the vaccine will be on the market will depend on the length of time required for manufacturers to obtain federal approval to produce it for use in interstate commerce. It is hoped that poultry producers will be able to get the vaccine in the near future. Informants here expressed the view that it is only a matter of “unwinding government red-tape” before approval is forthcoming.
In the field test, Dr. Beaudette confined his experiments almost wholly to intra-muscular injections of the vaccine with a hypodermic needle, but experiments were also conducted with the “stick” method with satisfactory results reported.
Dr. William H. Martin, director of the experiment station, predicted that the new vaccine would save the poultry industry of the U.S. hundreds of thousands of dollars in the next few years.
Previous important discoveries of Dr. Beaudette include the vaccine for laryngotracheitis and research, which pointed the way toward immunization of poultry against bronchitis.