Does antigen-specific cytokine response correlate with the experience of oculorespiratory syndrome after influenza vaccine?

During the 2000-2001 season in Canada, a newly identified oculorespiratory syndrome (ORS) was observed in patients after immunization with inactivated influenza vaccine. ORS was associated with a high proportion of microaggregates of unsplit virions in the implicated vaccine and had clinical features suggesting delayed-onset hypersensitivity. We explore the association between in vitro cytokine balance (type 1 vs. type 2) and clinical ORS after influenza vaccination. We report the balance of interferon (IFN)-gamma, interleukin (IL)-10, IL-5, and IL-13 expression by peripheral blood mononuclear cells (PBMC) among unvaccinated, vaccinated ORS-affected, and vaccinated ORS-unaffected persons after in vitro challenge with implicated and nonimplicated vaccines. Antigen-stimulated PBMC from vaccinated persons produced significantly more IFN-gamma than did those from unvaccinated persons. There was a statistically significant type 2 polarization among unvaccinated compared with vaccinated persons. Although vaccinated ORS-affected individuals had less of a type 1 basis than did vaccinated unaffected individuals, this difference was not statistically significant.