Leaky vaccine, leaky vaccines

  The term does appear, on exactly one page, the one about 

Marek's disease

"The Marek's disease vaccine is a "leaky vaccine", which means that only the symptoms of the disease are prevented.^[12] Infection of the host and the transmission of the virus are not inhibited by the vaccine."

Which is odd since a leaky vaccine is such an important thing, and potentially a very dangerous thing.  

Imperfect Vaccination Can Enhance the Transmission of Highly Virulent Pathogens

‘Leaky’ Vaccines Can Produce Stronger Versions of Viruses

Many livestock and human vaccines are leaky because they block symptoms but do not prevent infection or onward transmission. This leakiness is concerning because it increases vaccination coverage required to prevent disease spread and can promote evolution of increased pathogen virulence

.