Interpreting serological surveys using mixture models: the seroepidemiology of measles, mumps and rubella in England and Wales at the beginning of the 21st century

Abstract

A mixture modelling technique is applied to age-specific frequency distributions of quantitative results from serological surveys for measles, mumps and rubella using samples collected across the age range in England and Wales in 2000. In accordance with previous studies the analysis suggests that the antibody response to natural infection is stronger than that produced by vaccination, that vaccine-induced antibody levels wane with time and that levels of vaccine-induced antibody response vary for each virus infection being strongest for rubella and weakest for mumps. The current mumps epidemic in the United Kingdom is focused in cohorts born during 1982-1987 who were too old to have received routine MMR vaccination. In the cohort born in 1981-1985 the model estimates that 7.5% have no evidence of mumps specific IgG and 24.9% have the lowest level of detectable antibody. The similar proportions of mumps antibody in these categories among cohorts with opportunity for 1 or 2 doses of vaccine is a concern, as the degree to which these individuals are protected is unclear. Investigations into the efficacy of two doses of a mumps containing vaccine should be a priority during the current epidemic.

Seroprevalence of Rubella Antibodies among Adult Egyptian Females Aged 20-30 Years. Is there a Need for Rubella Vaccination?

“…Our finding was consistent with the results of other studies from Italy, Kenya, Poland, England, and Canada (17,22,(27)(28)(29) but in contrast to other study from Turkey reporting lack of association between these two variables (15).…”

Analysis of rubella antibody distribution from newborn dried blood spots using finite mixture models

“…Vyse et al [1] also found a similar age pattern of rubella seronegativity among women in England and Wales. This could be a consequence of the antenatal screening programme, where women who screened negative in a previous pregnancy were vaccinated post partum.…”

“…In previous studies where finite mixture models have been used, only age group has been of interest as a predictor of antibody level [1,3,8], and mixture models are therefore often stratified in order to determine the proportion of seronegative samples in each age group. This is important in order to establish whether further vaccination is required due to higher susceptibility in some cohorts.…”

“…This is partly a consequence of the difficulty in applying a meaningful cut-off value to continuous distributions of antibody concentrations in order to define seronegativity [1]. If a sample falls below a cut-off value set by the assay manufacturer, this does not necessarily indicate non-immunity, as IgG antibody assays for vaccinepreventable diseases are most often employed in screening to indicate a need for immunization.…”

A point-of-care test for measles diagnosis: detection of measles-specific IgM antibodies and viral nucleic acid

“…1 Outbreaks continue to occur in other global regions, primarily as a result of measles virus importation into areas where vaccine coverage has fallen to a suboptimal level and a susceptible cohort has accumulated. [2][3][4] Most regions have elimination goals and elimination strategies based on the maintenance of high vaccination coverage, for which political commitment is required. A key component of elimination plans is surveillance to monitor impact.…”