Original Research ARTICLE
Modeling the impact of Newcastle disease virus vaccinations on chicken production systems in Northeastern Madagascar
- 1School of Engineering and Applied Sciences, Harvard University, United States
- 2Department of Anthropology, Montclair State University, United States
- 3Madagascar Health and Environmental Research (MAHERY), Madagascar
- 4Institut Malgache des Vaccins Veterinaires, Madagascar
- 5Independent researcher, United States
- 6School of Public Health, Harvard University, United States
Chickens are a key source of nutrition for rural Malagasy communities. Due to high endemic
rates of Newcastle disease, it remains challenging to raise sustainable chicken flocks as a
consistent food source. Here, we explore the impact of triannual Newcastle disease virus (NDV)
vaccine interventions on the growth and herd immunity acquisition of Malagasy chicken flocks.
Between 2011 - 2018 we collected longitudinal data to assess the population dynamics of
chicken populations in remote Malagasy communities. In 2018, we launched a pilot campaign
for vaccination in six rural communities to determine the impacts on chicken survivorship
and productivity. We used these data to specify a mathematical model of realistic Malagasy
chicken population dynamics under a triannual vaccination regime. The mathematical model
represents an extension to conventional SIR models that allows for modeling the impact of specific
vaccinations on chicken flock dynamics, rather than estimation of parameters. Understanding
chicken population dynamics is important for realizing the potential for domestic chicken flocks to
serve as sustainable food sources. The results suggested that vaccination coverage of at least
40% is necessary over 5+ years to achieve population doubling, while complete herd immunity
may not be possible given the short duration of effectiveness of vaccination, and the high levels
of births and deaths in the chicken flocks.
Keywords: Poultry, Vaccination, Food security, Malnutrition, Animal-source foods, sustainable agriculture
Received: 01 Jul 2019;
Accepted: 28 Aug 2019.
Copyright: © 2019 Annapragada, Borgerson, Iams, Miharifetra, Crawford, Helin, Anjaranirina, Randriamady and Golden. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
Ms. Akshaya Annapragada, School of Engineering and Applied Sciences, Harvard University, Cambridge, 02138, Massachusetts, United States, email@example.com
Prof. Christopher D. Golden, School of Public Health, Harvard University, Boston, MA 02115, Massachusetts, United States, firstname.lastname@example.org