Date of Award

January 2024

Document Type

Open Access Thesis

Degree Name

Master of Public Health (MPH)


School of Public Health

First Advisor

Inci Yildirim


The landscape of the burden of invasive pneumococcal disease (IPD) in Massachusetts children has been shaped by both the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) in 2010 as well as the relationship with respiratory viruses, like influenza and COVID-19. The implementation of non-pharmaceutical interventions (NPIs) and dramatic decline in non-COVID circulating respiratory viruses during the initial waves of the COVID-19 pandemic provided a unique opportunity to evaluate the relationship between respiratory viruses and IPD in Massachusetts children. Using weekly surveillance data for IPD, influenza, and COVID-19 in Massachusetts children 5 years of age and younger from the Massachusetts Department of Public Health, we evaluated the impact of PCV13, the temporal relationship between influenza and IPD, and the impact of NPIs and COVID-19 on the burden of IPD in Massachusetts children. We found that there was a 78% decline in observed IPD cases compared to the predicted cases had PCV13 not been implemented and PCV13 averted approximately 1,135 cases of IPD in Massachusetts children. We observed a strong temporal association between influenza and IPD, with both diseases peaking within a few weeks of each other during the winter each year. Lastly, we found that during the state of emergency and implementation of non-pharmaceutical interventions (NPIs) in Massachusetts for COVID-19 between March 2020 and June 15, 2021, there was a 62% decrease in the observed number of cases compared to the predicted case counts had no COVID-19 non-pharmaceutical interventions been implemented and as a result, approximately 18 cases of IPD were averted. Both PCV13 and COVID-19 interventions led to a drastic decline in the incidence of IPD in Massachusetts children. After the relaxation of NPIs in June 2021, cases of IPD and influenza rebounded to pre-pandemic levels. We would like to expand upon this research by including RSV in our analysis and expanding our research into older children and the elderly.


This is an Open Access Thesis.

Open Access

This Article is Open Access