Every time I research something on Newcastle disease, I get immersed in the knowledge and wisdom of my virology lecturer of 45 years ago, the late Peter Spradbrow. Here is a little gem of his which I just came across - a 'postscript' to one of his scientific papers:
"A long time ago in Cambridge, the author [Spradbrow] met an old man who remembered the vaccine calf being brought around English villages. The calf would have been infected with what we now call vaccinia virus, the vaccine that protected against human smallpox. Not an ideal source of vaccine, but better than bovine exudate that had been transported by other means, and safer than the transfer of lymph from a human vaccine reaction. It was the best technique available at the time. Village chickens require access to Newcastle disease vaccine now, and flock owners deserve this service. We should strive for the best remedy that can be implemented, now."Pat Boland