Thanks for your question.
Basically there have been a few case reports of the development of CIDP after the administration of hepatitis B vaccine. However more studies are needed to establish a causal relationship. Based on the current evidence we cannot accept or reject a causal relationship between hepatitis B vaccine and CIDP.
Please rate the answer with a positive rating.
Yes they don't know for sure due to the lack of studies, that is the reason that it cannot be proved or disproved that there is a causal relationship between hepatitis B vaccine and CIDP.