This may be valid. After both the last 2 measles outbreaks that hit the news in the US it was discovered in many of the kids tested that the strain of measles was actually from the vaccine itself. Not sure if that's classified as a mutation but I don't think thats supposed to be able to happen and spread that way. Will follow up with sources after I'm off mobile

Edit: Here are a couple of sources. The first claims to have proven that someone on the vaccine schedule spread measles in 2011. However I will correct that I thought the disney case was similar but I think that one may have been wild measles and only a few vaccinated were infected. These are just food for thoughts

https://academic.oup.com/cid/article/58/9/1205/2895266

This one is more scientific and dry but is from the CDC I believe and showed among other things an increase in sporadic measles outbreaks among vaccinated

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC228449/

The whooping cough is more interesting. You can find multiple cases of outbreaks among highly vaccinated people but the symptoms are allegedly milder so the vaccine is possibly doing something positive about it. The CDC is warning the vaccine is losing effectiveness.

https://www.usatoday.com/story/life/allthemoms/2019/03/14/wh... https://www.livescience.com/53359-whooping-cough-outbreak-ra...

Anyway interested in any takes on that. I'm not wildly anti-vax but even these mild questions on it were immediately downvoted. I think its a complicated and fascinating thing to talk about when people aren't crybabies about it