Increasing rubella seronegativity despite a compulsory school law

Systematic Review of Measles and Rubella Serology Studies

Serological tests provide information about individual immunity from historical infection or immunization. Cross-sectional serological studies provide data about the age- and sex-specific immunity levels for individuals in the studied population, and these data can provide a point of comparison for the results of transmission models. In the context of developing an integrated model for measles and rubella transmission, we reviewed the existing measles and rubella literature to identify the results of national serological studies that provided cross-sectional estimates of population immunity at the time of data collection. We systematically searched PubMed, the Science Citation Index, and references we identified from relevant articles published in English. We extracted serological data for comparison to transmission model outputs. For rubella, serological studies of women of child-bearing age provide information about the potential risks of infants born with congenital rubella syndrome. Serological studies also document the loss of maternal antibodies, which occurs at different rates for the different viruses and according to the nature of the induced immunity (i.e., infection or vaccine). The serological evidence remains limited for some areas, with studies from developed countries representing a disproportionate part of the evidence. The collection and review of serological evidence can help program managers identify immunity gaps in the population, which may help them better understand the characteristics of individuals within their populations who may participate in transmission and manage risks.

Reviews of evidence regarding interventions to improve vaccination coverage in children, adolescents, and adults. The Task Force on Community Preventive Services

This paper presents the results of systematic reviews of the effectiveness, applicability, other effects, economic impact, and barriers to use of selected population-based interventions intended to improve vaccination coverage. The related systematic reviews are linked by a common conceptual approach. These reviews form the basis for recommendations by the Task Force on Community Preventive Services (the Task Force) regarding the use of these selected interventions. The Task Force recommendations are presented on pp. 92-96 of this issue.

Simultaneous control of measles and rubella by multidose vaccination schedules

There is currently a preference for using measles-mumps-rubella vaccine to simultaneously control these three diseases. Here an age-specific transmission model is used to investigate the consequences, on cases of measles and congenital rubella syndrome, of switching from a one-dose vaccination with this vaccine to a two-dose vaccination schedule. The model allows for a period of maternally acquired immunity and assumes that infection leads to permanent immunity, while vaccine-induced immunity is allowed to wane. The vaccination coverage at the second dose is expressed in terms of availability for vaccination, which depends on whether the individual received the first dose and the age of the individual. It is found that the optimal age for the first vaccination is not very sensitive to variations in the force of infection and is close to age 1 year for both measles and rubella. However, the optimal age for a second vaccination, offered indiscriminately, depends significantly on the age-specific forces of infection. This emphasizes that decisions about immunization schedules require reliable information about age-specific forces of infection in the community. In some circumstances control may be significantly more effective when the ages for the second dose differ for measles and rubella. It is found that the addition of a catch-up vaccination, offered to previously unvaccinated children at school entry, makes it more feasible to find a common age for the second dose that controls both measles and rubella effectively.