The Outbreak Potential for Measles and its Implications for Elimination

When the goal of measles elimination, or the absence of continuous transmission in a defined geographical area, was first proposed in 1962 by Alexander Langmuir, immediately prior to licensure of the first measles vaccine, an estimated six million deaths and 135 million cases occurred annually. Since that time, numerous efforts, initiatives, and goals have been initiated with great success, cutting measles incidence and mortality to fractions of what it once was. However, even now, with an effective, safe, and widely available vaccine, measles remains one of the leading causes of death among young children, resulting in approximately 90,000 deaths in 2016. Vaccination is the major reason for this success, yet remains the challenge for complete elimination and eradication: 2016 estimates indicate that only 85% of the children receive the first dose of measles vaccine. However, to meet regional elimination goals, vaccination likely needs to reach the target 95% coverage or more. Essential to this continued progress and the ultimate success of these elimination goals are methods for measuring the risks of transmission and outbreaks. Unfortunately, as we get closer to measles elimination, our current methods have demonstrated several shortcomings. The aims of this dissertation were to explore some areas where our current understanding and methods regarding outbreak and transmission of measles virus and other vaccine-preventable diseases fall short, and to develop new tools for estimating the outbreak potential among populations at various stages of control and elimination, specifically addressing potential failings of current methods