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

Background/

Objectives

Yellow fever virus (YFV) (Flaviviridae, Orthoflavivirus) 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.

Methods

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.

Results

Sera exhibited significantly more efficient neutralization of 17DD (mean reciprocal PRNT50 183, PRNT80 86, median reciprocal PRNT50 80, and PRNT80 40) compared to 17D-204 (mean reciprocal PRNT50 91, PRNT80 33, median reciprocal PRNT50 40, and PRNT80 10).

Conclusions

Our data indicate antigenic differences between 17D and 17DD vaccines.