Improving Measles Immunization Delivery

Controlling measles in low- and middle-income countries poses significant challenges, as discussed in by Kevin McCarthy in a CHDS seminar. McCarthy is a Senior Research Manager at the Institute for Disease Modeling within the Bill & Melinda Gates Foundation, where his team’s work guides investment decisions at the Foundation as well as at government and non-governmental organization partners.

McCarthy presented research that uses mathematical modeling to improve measles control policy decisions. He used a Nigerian case example to demonstrate the importance of how supplemental immunization activities (SIAs)—often referred to as “campaigns”—for measles vary widely in their impact based on their design and implementation. For example, delays in initiating SIAs may result in many additional measles infections. In a particularly striking example, he demonstrated how a 6-month delay could result in a twofold or greater increase in the size of the next outbreak, even if the extra time was accompanied by a substantial increase in coverage. McCarthy’s work helps guide decision makers toward more efficient SIA design, without necessarily increasing the number of vaccine doses or healthcare workers.

McCarthy also noted that it may not always be wise to target the country as a whole; it may be better to instead address the specific measles epidemic in each state of Nigeria. The appropriate approach depends on the accuracy of epidemiologic information within each state. McCarthy shared insights on how clinical and laboratory data can be used to infer the likely total number of measles cases over time, including unobserved cases.

Learn more: Read the publication, Optimization of Frequency and Targeting of Measles Supplemental Immunization Activities in Nigeria
Learn more: Read the publication, Distributional Impact of Supplementary Immunization Activities: Measles
Learn more: Resource Pack: Model Calibration and Validation