Modeling the Effectiveness of Infection Control Measures for the Elimination of Measles: Focus on Adults Born After 1970

Abstract

The German National Action Plan for the implementation of the WHO goal of measles elimination still faces considerable challenges regarding reaching its goal of increasing adult's vaccination rates and better outbreak management. METHODS The description of the target population group -adults born after 1970 - as well as other potentially vulnerable groups was carried out by means of a systematic literature review. A further systematic review outlines options for the prevention of new infections. Finally, recommendations for action are discussed. A modeling to clarify the influence of the various epidemiological parameters was performed. RESULTS For the population group of 20-29 year old persons, the vaccination rate was 79.8% and for the group of 30-39 year old people, 46.7%. In contrast, the seroprevalences showed a seropositivity of about 91.5% for the target group of the 20-29-year-olds and of approximately 95% for the 30-39-year-olds. A variety of vulnerable subgroups with low vaccination rates was identified: a negative attitude towards scientific and technical medicine due to religious or ideological backgrounds (vaccination rates of 50-75%), migrants (85.9-95.1%) and asylum seekers (89.9%). The systematic literature review shows that interventions for increasing the vaccination rate and a reduction of the contact rate via appropriate isolation measures in an outbreak context can be effective. With an ideal isolation, a vaccination rate of 73% could be sufficient to control an outbreak. The modeling clarifies the relevance of high vaccination rates compared with other influencing factors for an effective outbreak control. The extent of further interventions necessary to contain an outbreak was calculated. CONCLUSIONS The results obtained suggest that the basic immunisation rate should be increased further and, in the event of an outbreak, rigorous quarantine procedures should be implemented. The target group of young adults, especially those with a migratory background from countries with a high susceptibility to the disease, and other vulnerable subgroups, should be addressed in a more focused manner, and the previous focus on children and adolescents should be extended to adults. In order to do so, diversity-sensitive information and facilitated access to vaccinations appear particularly suitable.