Right. Lefties want to get rid of cattle.
Not going to happen
This chicken vaccine makes its virus more dangerous
The reason this is a problem for Marek’s disease is because the vaccine is “leaky.” A leaky vaccine is one that keeps a microbe from doing serious harm to its host, but doesn’t stop the disease from replicating and spreading to another individual. On the other hand, a “perfect” vaccine is one that sets up lifelong immunity that never wanes and blocks both infection and transmission.
It’s important to note childhood vaccines for polio, measles, mumps, rubella and smallpox aren’t leaky; they are considered “perfect” vaccines. As such, they are in no way in danger of falling prey to this phenomenon.
But the results do raise the questions for some human vaccines that are leaky – such as malaria, and other agricultural vaccines, such as the one being used against avian influenza, or bird flu.
Marek’s disease has plagued the chicken industry, it causes $2 billion in losses annually for fowl farmers across the globe. The virus attacks the brain, spawns tumors in the birds and comes in different varieties or “strains”, which are classified as “hot” or “cold” based on their brutality.
https://www.pbs.org/newshour/science/tthis-chicken-vaccine-makes-virus-dangerous