Herd Immunity et. all

This video from HealthCare Triage explains Herd Immunity very effectively and uses the example of Varicella (chicken box) after the introduction of the vaccine in 1995. Herd immunity was shown to be so effective that between 2004 and 2007 there were no deaths for children under 1 year old related to Chickenpox (the vaccine is only given to children older than 1). If that doesn't show effectiveness. I don't know what to tell you. (source: https://www.ncbi.nlm.nih.gov/pubmed/21788222)

Measles has shown evidence of herd immunity. Out breaks for Measles only occur in populations and communities where vaccination is low. While no vaccine prevents infection in 100% of cases, the reduction of infection combined with high innoculation in the population has been shown to reduce instances of measles substantially, until 1989 when vaccination rates fell. Occurance of measles has continued to increase (in un-or-undervaccinated population). (source: https://www.annualreviews.org/doi/abs/10.1146/annurev.me.43.020192.002315 Download the PDF for the full text)

Samoa:
Per wikipedia (there are 54 sources for you to peruse if you want), there were 5700 cases of measles and 87 deaths between September 2019 and January 2020. The affected island went from 74% vaccination in 2017 to 31% in 2018. The other islands (who didn't get an outbreak) had close to 99% vaccination.
They reached 94% vaccination on Dec 22nd 2019.
Samoa has a population of over 200,000. 3% of the population got measles, which is far from enough to provide immunity for the remaining 97%.

Whooping Cough:
Here is an interesting Manual I found with information about many diseases and vaccine statistics. Pertussis is Chapter 2.