17DD yellow fever vaccine: a double blind, randomized clinical trial of immunogenicity and safety on a dose-response study.
OBJECTIVE
To verify if the Bio-Manguinhos 17DD yellow fever vaccine (17DD-YFV) used in lower doses is as immunogenic and safe as the current formulation.


RESULTS
Doses from 27,476 IU to 587 IU induced similar seroconversion rates and neutralizing antibodies geometric mean titers (GMTs). Immunity of those who seroconverted to YF was maintained for 10 mo. Reactogenicity was low for all groups.


METHODS
Young and healthy adult males (n = 900) were recruited and randomized into 6 groups, to receive de-escalating doses of 17DD-YFV, from 27,476 IU to 31 IU. Blood samples were collected before vaccination (for neutralization tests to yellow fever, serology for dengue and clinical chemistry), 3 to 7 d after vaccination (for viremia and clinical chemistry) and 30 d after vaccination (for new yellow fever serology and clinical chemistry). Adverse events diaries were filled out by volunteers during 10 d after vaccination. Volunteers were retested for yellow fever and dengue antibodies 10 mo later. Seropositivity for dengue was found in 87.6% of volunteers before vaccination, but this had no significant influence on conclusions.


CONCLUSIONS
In young healthy adults Bio-Manguinhos/Fiocruz yellow fever vaccine can be used in much lower doses than usual. INTERNATIONAL REGISTER: ISRCTN 38082350.
Bio-Manguinhos, Fiocruz; Rio de Janeiro, Brazil.
Reinaldo M
RM
Martins
Maria de Lourdes S
Mde L
Maia
Roberto Henrique G
RH
Farias
Luiz Antonio B
LA
Camacho
Marcos S
MS
Freire
Ricardo
R
Galler
Anna Maya Yoshida
AM
Yamamura
Luiz Fernando C
LF
Almeida
Sheila Maria B
SM
Lima
Rita Maria R
RM
Nogueira
Gloria Regina S
GR
Sá
Darcy A
DA
Hokama
Ricardo
R
de Carvalho
Ricardo Aguiar V
RA
Freire
Edson
E
Pereira Filho
Maria da Luz Fernandes
Mda L
Leal
Akira
A
Homma
D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D004306:Dose-Response Relationship, Immunologic; D004311:Double-Blind Method; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology / Q000473:pathology; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D013997:Time Factors; D014611:Vaccination / Q000009:adverse effects / Q000379:methods*; D022341:Yellow Fever Vaccine / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology*; D055815:Young Adult
D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D022341:Yellow Fever Vaccine
Bio-Manguinhos/Fiocruz; dengue interactions; dose-response study; immunogenicity; reactogenicity; safety; viremia; yellow fever vaccine