Do a web search for "Tdap vaccine zika". Links to info about a Tdap vaccination program in Brazil that happened 9-12 months before cases of microcephaly started to be seen as well as scientific studies that showed no association between vaccination with Tdap during pregnancy & microcephaly in babies. It's a really interesting case study. this is also an interesting story although if you check the disinformation sites such as Snopes it's all a wacky 'conspiracy theory' ;-)