Absence of P2 protein in swine flu vaccines.

To test whether possible contamination with the neuritogenic P 2 protein from peripheral nerve myelin contributed to the increased incidence of Guillain-Barre syndrome during the national influenza immunization program, monovalent and bivalent vaccines from each manufacturer were tested using a recently developed radioimmunoassay for P 2 protein. No P 2 protein was found in any of the vaccines tested. ( JAMA 1982;247:495)