No it is not harder to say about HPV. The HPV vaccine is one of the sturdiest linkages between atomic-level scientific understanding and social policy.
HPV produces a protein called E6, which inhibits the protein called p53 in your cell. P53 is the centralized monitor of the health of the cell's DNA. When HPV inhibits the ability for the cell to monitor its DNA, it cannot respond to ordinary damage like UV, etc. This DNA damage builds up and triggers cancerous mutations that would otherwise have been repaired were the HPV E6 protein not inhibiting the p53 protein.
By getting a vaccine, HPV cannot infect you, thus it cannot produce the E3 protein, thus your p53 protein is functional, thus when you get ordinary DNA damage you repair it rather than accumulating cancer-causing damage. If you do not get a vaccine and you get infected with HPV you now have lost a significant checkpoint in preventing cancer.
Fortunately there are a number of different ways to justify the efficacy of particular technology prior to its implementation that do not require millions of people to prematurely contract cancer. If you have a hypothesis about a particular long-term consequence that could arise, by all means let's design a system to investigate it.
I get that it is problematic to even vaguely cast doubt on something that is a big public health win, but you are ignoring the context I commented in, where someone said:
but can we really say with confidence that the scientific research done on vaccination hasn't been influenced in the same way
Do we know for certain that HPV vaccine research has not been influenced by the companies selling the vaccines?
Rephrasing, I wasn't doubting the effectiveness of the HPV vaccines, I was pointing out that there are vaccines that we can be pretty much absolutely certain about.
The story is pretty well in on smallpox and polio.
Harder to say about HPV.