You are right, this graphic of course just is a quick overview and not a prove to anything. And you are also right that vaccines are not the only reason for this massive declines. Of course the other parts of modern medicine and hygenie also play a big role.
Bur don't underestimate the part vaccines did. Let's just as an example look at pertussis. In the 1970s Japan temporarely stopped the use of the vaccines. Let's look what happened then.
Here are so scientific articles about it:
https://www.ncbi.nlm.nih.gov/pubmed/15889991
https://www.ncbi.nlm.nih.gov/pubmed/7206322
https://www.ncbi.nlm.nih.gov/pubmed/3508651
I don't think the general medical level or hygenie dropped from one year to another. So maybe it just was the vaccines ;)
Of course I will answer to an article on vaccines if I think I can give value to the discussion. I followed you to not miss it. Would be glad if you do the same, I will also post about this topic for sure.
Great I will be very interested to read your posts when they arrive!
Followed in anticipation! =)