CONTROLLING MEASLES USING SUPPLEMENTAL IMMUNIZATION ACTIVITIES: A MATHEMATICAL MODEL TO INFORM OPTIMAL POLICY

Tuesday, 13th of January 2015

“The model also suggests that a single SIA may give the impression of having controlled measles due to a post-vaccination “honeymoon." Such potentially unexpected effects can have disastrous consequences on plans for national elimination or even global eradication goals. This underscores the importance of using predictive models that account for transmission events, rather than relying solely on surveillance based on reported cases, to inform decision making about vaccination."                                                                     

CONTROLLING MEASLES USING SUPPLEMENTAL IMMUNIZATION ACTIVITIES: A MATHEMATICAL MODEL TO INFORM OPTIMAL POLICY

Verguet S¹, Johri M², Morris SK³, Gauvreau CL⁴, Jha P⁴, Jit M⁵.

Author information

 

¹Department of Global Health, University of Washington, Seattle, WA, USA. Electronic address: verguet@uw.edu.

• ²International Health Unit (USI), University of Montreal Hospital Research Centre (CR-CHUM), Montreal, Québec, Canada; Department of Health Administration, School of Public Health, University of Montreal, Montreal, Québec, Canada.
• ³Division of Infectious Diseases, Hospital for Sick Children, Toronto, Ontario, Canada; Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada; Center for Global Health Research, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
• ⁴Center for Global Health Research, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
• ⁵Modelling and Economics Unit, Public Health England, London, United Kingdom; Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom.

Abstract below ; full text is at http://www.sciencedirect.com/science/article/pii/S0264410X14016077

BACKGROUND:

The Measles & Rubella Initiative, a broad consortium of global health agencies, has provided support to measles-burdened countries, focusing on sustaining high coverage of routine immunization of children and supplementing it with a second dose opportunity for measles vaccine through supplemental immunization activities (SIAs). We estimate optimal scheduling of SIAs in countries with the highest measles burden.

METHODS:

We develop an age-stratified dynamic compartmental model of measles transmission. We explore the frequency of SIAs in order to achieve measles control in selected countries and two Indian states with high measles burden. Specifically, we compute the maximum allowable time period between two consecutive SIAs to achieve measles control.

RESULTS:

Our analysis indicates that a single SIA will not control measles transmission in any of the countries with high measles burden. However, regular SIAs at high coverage levels are a viable strategy to prevent measles outbreaks. The periodicity of SIAs differs between countries and even within a single country, and is determined by population demographics and existing routine immunization coverage.

CONCLUSIONS:

Our analysis can guide country policymakers deciding on the optimal scheduling of SIA campaigns and the best combination of routine and SIA vaccination to control measles.

Copyright © 2014. Published by Elsevier LtdBottom of Form