T cell epitopes absolutely do matter in this conversation since they are currently one of the main mechanisms that prevent replication. The live attenuated vaccines used in chickens against marek's disease are considered "permissive vaccines" and don't prevent replication. That is why I asked you to provide a paper that provided the proof that the newer variants were evading t cell epitopes.
Even if the current vaccines were permissive, that wouldn't be the end of the world since the inactivated polio vaccine (IPV) is also a permissive vaccine. Basically it prevents the systemic spread of wild type polio but doesn't prevent the replication of the virus in the gut where it normally wants to replicate and shed.
Fun fact #1: the author of the paper you posted (Andrew Read) doesn't even agree that the covid vaccines are leaky
“He's taking very careful work about evolutionary scenarios of the future, and from that, erroneously concluding that people should not be vaccinated now," says Andrew Read, professor of biology and entomology at Pennsylvania State University and author of the study.
www.forbes.com
Fun Fact #2: the herpes virus that causes marek's disease is an example of a virus that became more virulent even before a vaccine existed for it.