I am pro-vax but also pro-choice ITMS. I have a science degree and have done a lot of research from a lot of sources on vaccination. So certainly not 'ignorant' and 'uneducated'. Actually a lot of what that lady had on her website about chemicals and nutrition was scientifically incorrect!
The anti-vaxxers I know IRL are not agressive, however some do a lot of work spreading incorrect information from the AVN etc which is very damaging as I have seen people choose not to vax on that! (Im not saying dont make an educated choice, just dont take the AVN as being correct)