Could a Shigella vaccine impact long-term health outcomes?: Summary report of an expert meeting to inform a Shigella vaccine public health value proposition, March 24 and 29, 2021
Karoun H. Bagamian,
Chloe Puett,
John D. Anderson, IV,
Farzana Muhib,
Clint Pecenka,
Jere Behrman,
Robert F. Breiman,
Ijeoma Edoka,
Susan Horton,
Gagandeep Kang,
Karen L. Kotloff,
Claudio F. Lanata,
James A. Platts-Mills,
Firdausi Qadri,
Elizabeth T. Rogawski McQuade,
Christopher Sudfeld,
Pascale Vonaesch,
Thomas F. Wierzba,
Suzanne Scheele
Affiliations
Karoun H. Bagamian
Bagamian Scientific Consulting, LLC, Gainesville, FL 32601, USA; Department of Environmental and Global Health, University of Florida, Gainesville, FL 32603, USA; Corresponding author.
Chloe Puett
Stony Brook University, Department of Family, Population & Preventative Medicine, Program in Public Health, Stony Brook, NY 11794, USA
John D. Anderson, IV
Bagamian Scientific Consulting, LLC, Gainesville, FL 32601, USA
Farzana Muhib
Center for Vaccine Innovation and Access, PATH, 455 Massachusetts Ave NW, Washington, DC 20001, USA
Clint Pecenka
Center for Vaccine Innovation and Access, PATH, Seattle, WA 98121, USA
Jere Behrman
Department of Economics and Sociology, University of Pennsylvania, Philadelphia, PA 19104, USA
Robert F. Breiman
Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
Ijeoma Edoka
Health Economics and Epidemiology Research Office, Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
Susan Horton
School of Public Health Sciences, University of Waterloo, Waterloo, ON N2L 3G1, Canada
Gagandeep Kang
Division of Gastrointestinal Sciences, Christian Medical College, Vellore 632004, India
Karen L. Kotloff
Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
Claudio F. Lanata
Instituto de Investigacion Nutricional, Lima, Peru
James A. Platts-Mills
Division of Infectious Diseases & International Health, University of Virginia, Charlottesville, VA 22903, USA
Firdausi Qadri
International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
Elizabeth T. Rogawski McQuade
Department of Epidemiology, Emory University, Atlanta, GA 30322, USA
Christopher Sudfeld
Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
Pascale Vonaesch
Department of Fundamental Microbiology, University of Lausanne, Switzerland
Thomas F. Wierzba
Department of Internal Medicine, Section on Infectious Diseases, Winston-Salem, NC 27157, USA
Suzanne Scheele
Center for Vaccine Innovation and Access, PATH, 455 Massachusetts Ave NW, Washington, DC 20001, USA
Shigellosis is a leading cause of diarrhea and dysentery in young children from low to middle-income countries and adults experiencing traveler’s diarrhea worldwide. In addition to acute illness, infection by Shigella bacteria is associated with stunted growth among children, which has been linked to detrimental long-term health, developmental, and economic outcomes. On March 24 and 29, 2021, PATH convened an expert panel to discuss the potential impact of Shigella vaccines on these long-term outcomes. Based on current empirical evidence, this discussion focused on whether Shigella vaccines could potentially alleviate the long-term burden associated with Shigella infections. Also, the experts provided recommendations about how to best model the burden, health and vaccine impact, and economic consequences of Shigella infections. This international multidisciplinary panel included 13 scientists, physicians, and economists from multiple relevant specialties.According to the panel, while the relationship between Shigella infections and childhood growth deficits is complex, this relationship likely exists. Vaccine probe studies are the crucial next step to determine whether vaccination could ameliorate Shigella infection-related long-term impacts. Infants should be vaccinated during their first year of life to maximize their protection from severe acute health outcomes and ideally reduce stunting risk and subsequent negative long-term developmental and health impacts. With vaccine schedule crowding, targeted or combination vaccination approaches would likely increase vaccine uptake in high-burden areas. Shigella impact and economic assessment models should include a wider range of linear growth outcomes. Also, these models should produce a spectrum of results—ones addressing immediate benefits for usual health care decision-makers and others that include broader health impacts, providing a more comprehensive picture of vaccination benefits. While many of the underlying mechanisms of this relationship need better characterization, the remaining gaps can be best addressed by collecting data post-vaccine introduction or through large trials.
