a) Hypersensitivity reactions of the nervous system (serogenetic) are responible in a good number of cases. Poser and Fowler describe similarities between GBS and serum disease.
b) Toxic reactions may occur soon after inoculation of the patient in the absense of specific allergies.
c) Viral infection of the brain by vaccinal viruses (4) or by reactivation of latent germs (21).
d) Activation of latent auto-immune diseases (21).

The fact that different vaccines from different manufacturers lead to similar complications, suggests that these are not the consequence of the impurity of a certain vaccine, but a risk inherent in any influenza vaccine.

Contra-Indications

Any impairment of the immune system should be considered a contra-indication.

1. Allergies, especially to any substance of the vaccines; allergy to proteins, cowsmilk etc.; hay fever... Allergic constitutions often lead to hypersensitive reactions (8).
2. Akute infections with or without fever must be a reason to postpone or abandon vaccination.
3. Chronic impairment of the immune system (auto-immune diseases) imply an increased risk in case of vaccination.

References

1. Beyer, W.E.P.; et. al. Influenza-epidemie in een verpleeghuis door een virus dat niet in het vaccin was opgenomen. Ned Tijdschr Geneeskd, 1993; 137/39:1973-7
2. Palache, A.M.; Influenza subunit vaccine - ten years experience. Eur J Clin Res, 1992; 3:117-38
3. Coulter, H.L.; Fisher, B.L. DPT, a shot in the dark, p 275. Harcourt Brace Jovanovich
4. Ehrengut, W.; Allerdist, H.; Über neurologische Komplikationen nach der Influenzaschutzimpfung. Münch. med. Wschr., 1977; 119/705-710 5. Rabin, J.; JAMA, 1973; 225:63
6. Stuart-Harris, C.H.; BMJ, 1966; 149:1(1966)217
7. Wells, C.E.C.; BMJ, 1971/2:755
8. Hennessen, W.; Jacob, H.; Quast, U.; Neurologische Affektionen nach Influenza - Impfung. Der Nervenarzt, 1978; 49/90-96
9. Morb. a. Mort.; Wkly Rep. 25 (1977) 430; 26 (1977) 7; 26 (1977) 52
10. Bryan, J.; Noble, G.R.; Guillain-Barré Syndrome after administration of killed vaccines. Genf: Ref: IABS Symposium on Influenza Immunization 1.6-4.6.1977
11. Felix, J.K.; Schwartz, R.H.; Myers, G.J.; Isolated Hypoglossal Nerve Paralysis Following Influenza Vaccination. Amer. J. Dis. Child., 1976; 130/1:82-3
12. Furlow, T.W.; Neuropathy after Influenza Vaccination. Lancet, 1977; i: 253
13. Schumm, F.; Neurologische Komplikationen nach Grippe-Impfung. Fragen aus der Praxis. Dtsch med Wschr, 1976; 101/18:720-21
14. Woods, C.A.; Ellison, G.W.; Encephalopathy following Influenza Immunization. J. Pediat., 1964; 65,5:745-8
15. Warren, W.R.; Encephalopathy due to Influenza Vaccine. A.M.A. Archives of Internal Medicine, 1956; 97:803
16. JAMA, 1962;181:70
17. Miller, H.; Cendrowski, W.; Schapira, K.; Multiple Sclerosis and Vaccinations. BMJ 1967;April 22: 210-3
18. Yahr, M.D.; Lobo-Antunes, J.; Relapsing Encephalomyelitis Following the Use of Influenza Vaccine. Arch Neurol, 1972; 27:182-3
Hennessen et al
19. Sibley, W.; Foley, J.; Infection and Immunization in Multiple Sclerosis. Ann Ac Sci fenn , 1965; A 122:457-68
20. Sibley, W.; Bamford, C.R.; Laguna, J.F.; Influenza vaccination in Patients with Multiple Sclerosis. JAMA, 1976; 236, 17:1965-66
21. Stöhr, M.; Mayer, K.; Neurologische Erkrankungen nach Grippeschutzimpfung. Med. Welt, 1976; 27/912-14