I don't know if the concept of 'herd immunity' is particularly useful as it relates to seasonal respiratory illnesses. Equilibrium might be more appropriate.

While vaccines for certain illnesses are quite successful/useful. Those for things like flu and coronaviruses are less so.

From a thorough Cochrane review on the published science: "Inactivated influenza vaccines probably reduce influenza in healthy adults from 2.3% without vaccination to 0.9%" (https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD001269.pub6/full).

And from the British Medical Journal, a truthful discussion of the stats around the new mRNA vaccines (https://blogs.bmj.com/bmj/2021/01/04/peter-doshi-pfizer-and-modernas-95-effective-vaccines-we-need-more-details-and-the-raw-data/).

The pharmaceutical and medical industries also generally omit any discussion around the fact that most cases of influenza like illness do not originate from influenza viruses, but from other similar viruses (which has implications for flu vaccine efficacy).

I cover some of that here (with many citations to peer reviewed studies): https://medium.com/illumination-curated/the-unexpected-case-of-the-disappearing-flu-64fd1fa5e909

So, truthfulness on the part of public health professionals would also go a long way, as there are people who are aware of these unaddressed facts.