The case for a typhoid vaccine probe study and overview of design elements.
Recent advances in typhoid vaccine, and consideration of support from Gavi, the Vaccine Alliance, raise the possibility that some endemic countries will introduce typhoid vaccine into public immunization programs. This decision, however, is limited by lack of definitive information on disease burden. We propose use of a vaccine probe study approach. This approach would more clearly assess the total burden of typhoid across different syndromic groups and account for lack of access to care, poor diagnostics, incomplete laboratory testing, lack of mortality and intestinal perforation surveillance, and increasing antibiotic resistance. We propose a cluster randomized trial design using a mass immunization campaign among all age groups, with monitoring over a 4-year period of a variety of outcomes. The primary outcome would be the vaccine preventable disease incidence of prolonged fever hospitalization. Sample size calculations suggest that such a study would be feasible over a reasonable set of assumptions.
Agence de Médecine Preventive, 13 Chemin du Levant, 01210 Ferney-Voltaire, France. Electronic address: bgessner@aamp.org.
Bradford D
BD
Gessner
Center for Inference and Dynamics of Infectious Diseases, Fred Hutchinson Cancer Research Center and Department of Biostatistics, University of Washington School of Public Health, Seattle, WA, USA.
M Elizabeth
ME
Halloran
Sabin Vaccine Institute, Vaccine Advocacy and Education, Washington, DC, USA.
Imran
I
Khan
D000367:Age Factors; D016000:Cluster Analysis; D003906:Developing Countries / Q000706:statistics & numerical data; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D017589:Immunization Programs; D032541:Mass Vaccination; D016032:Randomized Controlled Trials as Topic; D012107:Research Design; D012485:Salmonella typhi / Q000276:immunology; D013997:Time Factors; D014435:Typhoid Fever / Q000191:economics / Q000453:epidemiology / Q000517:prevention & control*; D014436:Typhoid-Paratyphoid Vaccines; D064166:Vaccine Potency
D014436:Typhoid-Paratyphoid Vaccines
Clinical trial; Disease burden; Salmonella typhi; Trial design; Typhoid; Typhoid vaccine; Vaccine; Vaccine probe study