Sustained Transmission of Mumps in a Highly Vaccinated Population: Assessment of Primary Vaccine Failure and Waning Vaccine-Induced Immunity

Abstract

From January to July 1991, an outbreak of mumps occurred in Maury County, Tennessee. At the primarily affected high school, where 98% of students and all but 1 student with mumps had been vaccinated before the outbreak, 68 mumps cases occurred among 1116 students (attack rate, 6.1%). Students vaccinated before 1988 (the first year mumps vaccination was required for school attendance in Tennessee) may have been at greater risk of mumps than those vaccinated later (65[6.1%] of 1001 vs. 2[2.2%] of 89; risk ratio, 2.9; 95% confidence interval, 0.7-11.6). Of 13 persons with confirmed mumps who underwent serologic testing, 3 lacked IgM antibody in well-timed acute- and convalescent-phase serum specimens. Vaccine failure accounted for a sustained mumps outbreak in a highly vaccinated population. Most mumps cases were attributable to primary vaccine failure. It is possible that waning vaccine-induced immunity also played a role.

Sero-epidemiology of mumps in western Europe

“…Failure of the mumps vaccine has been attributed to primary vaccine failure [24]. Sero-conversion rates following mumps vaccination, estimated by modelling ESEN sero-prevalence data, varied in the different countries [12].…”

Characterization of three co-circulating genotypes of the small hydrophobic protein gene of mumps virus.

“…The occurrence of sporadic mumps outbreaks is a wellknown phenomenon, even in populations with high vaccine coverage (Wharton et al, 1988 ;Hersh et al, 1991 ;Briss et al, 1994 ;Ku$ nkel et al, 1994Ku$ nkel et al, , 1995Germann et al, 1996 ;Stro$ hle et al, 1996 ;Afzal et al, 1997 b). In the epidemics in Switzerland in 1992and in Portugal in 1996, the population was vaccinated with a heterologous genotype (Ku$ nkel et al, 1994 ;Stro$ hle et al, 1996 ;Afzal et al, 1997 b).…”

Epidemiology and the economic assessment of a mumps outbreak in a highly vaccinated population, Orange County, New York, 2009–2010

“…27 In previously reported studies crowded educational settings such as schools, universities, and camps, have played an important role in transmission of mumps. 5,[28][29][30][31][32][33] No evidence has suggested that other factors such as handling changes and vaccine lots were risk factors for vaccine failure.…”