title: Dynamics of the serologic response in vaccinated and unvaccinated mumps cases during an epidemic.
abstract: In the last decade, several mumps outbreaks were reported in various countries despite high vaccination coverage. In most cases, young adults were affected who have acquired immunity against mumps solely by vaccination and not by previous wild-type mumps virus infection. To investigate mumps-specific antibody levels, functionality and dynamics during a mumps epidemic, blood samples were obtained longitudinally from 23 clinical mumps cases, with or without a prior history of vaccination, and from 20 healthy persons with no serological evidence of recent mumps virus infection. Blood samples from mumps cases were taken 1-2 months and 7-10 months after onset of disease. Both vaccinated and unvaccinated mumps cases had significantly higher geomean concentrations of mumps-specific IgG (resp. 13,617 RU/ml (95% CI of 9,574-19,367 RU/ml) vs. 1,552 (445-5412) RU/ml at 1-2 months; and 6,514 (5,247-8,088) RU/ml vs. 1,143 (480-2,725) RU/ml at 7-10 months) than healthy controls (169 (135-210) RU/ml) (p = 0.001). Patterns in virus-neutralizing (VN) antibody responses against the mumps vaccine virus were similar, vaccinated and unvaccinated mumps cases had significantly higher ND50 values at both time points of sampling (resp 4,695 (3,779-5,832) RU/ml vs. 1,533 (832-2,825) RU/ml at 1-2 months; 2,478 (1,968-3,122) RU/ml vs. 1,221 (1,029-1,449) RU/ml at 7-10 months) compared with (previously vaccinated) healthy controls (122 (196-76)) RU/ml) (p = 0.001) The unvaccinated mumps cases had significantly lower mumps-specific IgG and VN antibody concentrations at both sampling points compared with previously vaccinated cases, but their antibody concentrations did not differ significantly at the 2 time points. In contrast, the mumps-specific IgG and VN antibody concentrations of the previously vaccinated mumps cases were significantly higher within the first 2 months after onset of mumps and declined thereafter, characteristic for a secondary response. A moderate correlation was found between the level of mumps-specific IgG serum antibodies and VN antibodies for the mumps cases (r = 0.64; p<0.001).
authors.affiliation: a Centre for Infectious Disease Control; National Institute for Public Health and the Environment (RIVM) ; Bilthoven , the Netherlands.
authors.forename: Patricia
authors.initials: P
authors.lastname: Kaaijk
authors.forename: Sigrid
authors.initials: S
authors.lastname: Gouma
authors.forename: Hinke I
authors.initials: HI
authors.lastname: Hulscher
authors.forename: Wanda G
authors.initials: WG
authors.lastname: Han
authors.forename: Deborah E
authors.initials: DE
authors.lastname: Kleijne
authors.forename: Rob S
authors.initials: RS
authors.lastname: van Binnendijk
authors.forename: Cécile A
authors.initials: CA
authors.lastname: van Els
mesh_terms: D000293:Adolescent; D000328:Adult; D057134:Antibodies, Neutralizing / Q000032:analysis; D000914:Antibodies, Viral / Q000032:analysis; D058872:Epidemics; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D008297:Male; D008875:Middle Aged; D009107:Mumps / Q000453:epidemiology* / Q000276:immunology* / Q000517:prevention & control; D009108:Mumps Vaccine / Q000276:immunology*; D009500:Neutralization Tests; D014611:Vaccination; D017778:Vaccines, Combined; D055815:Young Adult
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D007074:Immunoglobulin G; D009108:Mumps Vaccine; D017778:Vaccines, Combined
keywords: 95% CI, lower and upper 95% confidence intervals of GMC; GMC, geometric mean concentration; MMR, measles mumps and rubella; ND50, reciprocal virus-neutralizing antibody dose; RU/ml, RIVM units per ml; VN, virus-neutralizing antibody; antibody dynamics; antibody response; epidemic; mumps; vaccination; virus neutralization