Your study and the parent's are looking at slightly different things. Essentially, the parent's study is saying that variant virulence has gone up over time, potentially related to leaky vaccine use. Your study is saying that leaky vaccine use can still be useful at reducing viral load and producing better outcomes than not vaccinating. These two different things can be true simultaneously.

I encourage you and the parent to read the full text of the Plos paper (if you have not already). It does not show that vaccines selected for more virulent strains as is claimed in the Quanta magazine article and by the parent. It only shows definitively (In a sample size of 100 birds) that birds don’t transmit virus after they die.

It also begs the question, what point is the parent trying to make here? That we should just let covid rip so it kills off all the vulnerable?

"It only shows definitively (In a sample size of 100 birds) that birds don’t transmit virus after they die."

They also showed that the cumulative genomes shed where higher for vaccinated birds vs unvaccinated birds when dealing with more virulent strains. And that this did influence the sentinel infections. Yes, that's due to death. It still shows that if mutations become statistically more likely with the cumulative genome shedding, then leaky vaccines do not prevent this and the genomic pool will be skewed more to the virulent side than it would have been otherwise. That's all pretty definitive. Now, does that definitely support that a specific outcome will occur, like vaccines causing more sereve strains- no.

Although this is kind of besides my point - that the two studies are not in conflict and perhaps the two parties are arguing two separate topics.

Yeah, I think part of what is so vexing about Delta is that deaths don’t create a backstop against spread. Someone with a severe or terminal case of Delta can still infect 10+ individuals before they pass.