Are there any papers arguing against vaccination in French?
I wish you good luck, as 99.99% of the anecdotal claims out there that conclude vaccination is bad are based on unfounded rumors. 

Note that much of the negative public opinion is based on a fraudulent (and retracted) paper by Wakefield in The Lancet (1998). Unfortunately for you, however, it is in English. 

My French is a bit rusty, but if you go to Google Scholar and type in a search term like vaccination results in autism (les résultats de la vaccination dans l'autisme) or Wakefield vaccination autisme something might pop up in French that advocates against vaccination.