Immune responses to mumps vaccine in adults who were vaccinated in childhood.
BACKGROUND
In a mumps outbreak in the United States, many infected individuals were adults who had received 2 doses of mumps vaccine. The persistence of cellular immunity to mumps vaccine has not been defined.


METHODS
This was an observational, nonrandomized cohort study evaluating cell-mediated and humoral immunity to mumps in 10 vaccinated and 10 naturally immune adults. Mumps-specific T cell activation and interferon (IFN)-gamma production were measured using lymphoproliferative and flow cytometry assays, and mumps immunoglobulin (Ig) G was measured using enzyme-linked immunosorbent assay.


RESULTS
T cell immunity to mumps was high in both groups; 70% of vaccinated and 80% of naturally immune individuals had a positive (> or =3) stimulation index (SI) (P = 1.0). The mean percentages of mumps-specific CD4+ T cells that expressed CD69 and produced IFN-gamma were equivalent in the 2 groups: 0.06% and 0.12%, respectively (P = .11). The mean SIs in the groups were also equivalent, although IFN-gamma concentrations from cultures stimulated with mumps antigen were higher in naturally immune adults than in vaccinated adults (P < or = .01). All adults were positive for mumps IgG.


CONCLUSIONS
T and B cell immunity to mumps was detected in adults at least 10 years after immunization. Except for IFN-gamma release, responses in vaccinated adults paralleled those observed in naturally immune individuals.
Hanna-Wakim
Rima
R
Department of Pediatrics, Stanford University School of Medicine, Stanford, California 94305-5208, USA.
Yasukawa
Linda L
LL
Sung
Phillip
P
Arvin
Ann M
AM
Gans
Hayley A
HA
D000328:Adult; D000914:Antibodies, Viral / Q000097:blood*; D000917:Antibody Formation; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D049109:Cell Proliferation; D015331:Cohort Studies; D005434:Flow Cytometry; D006801:Humans; D007111:Immunity, Cellular; D007156:Immunologic Memory; D007371:Interferon-gamma / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D009108:Mumps Vaccine / Q000276:immunology*; D009109:Mumps virus / Q000276:immunology*; D013601:T-Lymphocytes / Q000502:physiology
D000914:Antibodies, Viral; D009108:Mumps Vaccine; D007371:Interferon-gamma