Immune Responses to Mumps Vaccine in Adults Who Were Vaccinated in Childhood
Department of Pediatrics, Stanford University School of Medicine, Stanford, California
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)–γ 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 (
3) stimulation index (SI) (
). The mean percentages of mumps‐specific CD4+ T cells that expressed CD69 and produced IFN‐γ were equivalent in the 2 groups: 0.06% and 0.12%, respectively (
). The mean SIs in the groups were also equivalent, although IFN‐γ concentrations from cultures stimulated with mumps antigen were higher in naturally immune adults than in vaccinated adults (
). All adults were positive for mumps IgG.
Conclusion.T and B cell immunity to mumps was detected in adults at least 10 years after immunization. Except for IFN‐γ release, responses in vaccinated adults paralleled those observed in naturally immune individuals.
Received 14 November 2007; accepted 3 January 2008; electronically published 17 April 2008.
Cited by
Online publication date: 15-May-2009.
Online publication date: 15-Feb-2009.
Online publication date: 1-Dec-2008.
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Potential conflicts of interest: none reported.
Presented in part: Pediatric Academic Societies' Annual Meeting, Toronto, 5–8 May 2007 (poster 754063).
Financial support: National Institute of Allergy and Infectious Diseases (grant AI37127).
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Present affiliation: private practice, Beirut, Lebanon.