In 1994, the Institute of Medicine (IOM) reported that there was compelling scientific evidence to conclude that tetanus, DT, and Td vaccines can cause Guillain-Barre syndrome (GBS), including death; brachial neuritis; and death from anaphylaxis (shock). However, in 2012, the IOM committee reported that there was a lack of evidence to support or reject a causal association between GBS and tetanus, diphtheria toxoid, and acellular pertussis vaccines.
This committee also reported a lack of evidence to support or reject a causal association between encephalopathy, encephalitis, infantile spasms, seizures, ataxia, autism, acute disseminated encephalomyelitis (ADEM), transverse myelitis, chronic inflammatory disseminated polyneuropathy, optic neuritis, onset of multiple sclerosis in adults, relapse of multiple sclerosis in adults, relapse of multiple sclerosis in children, opsoclonus myoclonus syndrome, or Bell’s palsy and tetanus, diphtheria toxoid and acellular pertussis vaccines. There was, however, enough evidence to convincingly support an association between anaphylaxis and tetanus, diphtheria toxoid, and acellular pertussis vaccines.