Differential Neutralization Profiles of 17DD Vaccinated Population to 17D-204 and 17DD Vaccine Strains.

: Yellow fever virus (YFV) (, ) is the etiologic agent of yellow fever (YF), a vector-borne disease with significant morbidity and mortality across the tropics and neotropics, despite having a highly efficacious and safe vaccine (17D). Vaccination provides lifelong protection from YF disease mediated by humoral immunity. There are several versions of the original 17D vaccine: 17D-204 (marketed in the USA as YF-VAX, in France as Stamaril, and in China as Tiantan-V), 17D-213 (Russian Federation), and 17DD (by FIOCRUZ in Brazil). Vaccines produced in the US, France, Senegal, China, and Russia represent 17D-204-derived strains, whereas the Brazilian 17DD has a unique passage/attenuation history from 17D-204-derived strains. Their functional differences in the neutralization profiles are not known. : The Plaque Reduction Neutralization Test (PRNT) was used to determine the neutralization profiles of sera from 209 patients that were previously vaccinated with the 17DD strain against both 17D-204 and 17DD. : Sera exhibited significantly more efficient neutralization of 17DD (mean reciprocal PRNT 183, PRNT 86, median reciprocal PRNT 80, and PRNT 40) compared to 17D-204 (mean reciprocal PRNT 91, PRNT 33, median reciprocal PRNT 40, and PRNT 10). : Our data indicate antigenic differences between 17D and 17DD vaccines.