Vaccine failure, seasonality and demographic changes associate with mumps outbreaks in Jiangsu Province, China:...

Area of Science:

• Epidemiology
• Mathematical Modeling
• Public Health

Background:

• The Measles, Mumps, and Rubella (MMR) vaccine program in Jiangsu, China, initially reduced mumps cases after its 2008 introduction.
• A resurgence of mumps cases since May 2015 has raised concerns, with some studies pointing to vaccine failure.

Purpose of the Study:

• To investigate factors beyond vaccine failure contributing to the recent mumps resurgence in Jiangsu province.
• To analyze changes in seasonal transmission patterns and demographic structures influencing mumps epidemics.

Main Methods:

• Utilized an age-structured mathematical model to analyze mumps epidemic data from January 2005 to May 2019.
• Divided the epidemic history into three stages: pre-vaccine, effectively controlled, and resurgence.
• Compared epidemic features across stages, considering demographic structures and physical contact rates.

Main Results:

• Mumps transmission rates showed increased summer transmission and a drop in November during the resurgence stage compared to the pre-vaccine stage.
• Shifts in demographic structures explained age-specific outbreaks, with children around 10 years old affected in the early stage and around 5 years old in the resurgence stage.
• Identified associations between vaccine failure, altered seasonality, and demographic changes with recent mumps outbreaks.

Conclusions:

• Vaccine failure, changes in seasonality, and demographic shifts are significant contributors to recent mumps outbreaks in Jiangsu, China.
• The study provides insights into mumps dynamics considering age, vaccination, seasonality, and demographics.
• Findings can aid health planners in developing targeted preventive interventions for high-risk periods.