Immunogenicity of Fractional-Dose Vaccine during a Yellow Fever Outbreak - Final Report

Copyright © 2018 Massachusetts Medical Society..

BACKGROUND: In 2016, the response to a yellow fever outbreak in Angola and the Democratic Republic of Congo led to a global shortage of yellow fever vaccine. As a result, a fractional dose of the 17DD yellow fever vaccine (containing one fifth [0.1 ml] of the standard dose) was offered to 7.6 million children 2 years of age or older and nonpregnant adults in a preemptive campaign in Kinshasa. The goal of this study was to assess the immune response to the fractional dose in a large-scale campaign.

METHODS: We recruited participants in four age strata at six vaccination sites. We assessed neutralizing antibody titers against yellow fever virus in blood samples obtained before vaccination and at 1 month and 1 year after vaccination, using a plaque reduction neutralization test with a 50% cutoff (PRNT50). Participants with a PRNT50 titer of 10 or higher were considered to be seropositive. Those with a baseline titer of less than 10 who became seropositive at follow-up were classified as having undergone seroconversion. Participants who were seropositive at baseline and who had an increase in the titer by a factor of 4 or more at follow-up were classified as having an immune response.

RESULTS: Among 716 participants who completed the 1-month follow-up, 705 (98%; 95% confidence interval [CI], 97 to 99) were seropositive after vaccination. Among 493 participants who were seronegative at baseline, 482 (98%; 95% CI, 96 to 99) underwent seroconversion. Among 223 participants who were seropositive at baseline, 148 (66%; 95% CI, 60 to 72) had an immune response. Lower baseline titers were associated with a higher probability of having an immune response (P<0.001). Among 684 participants who completed the 1-year follow-up, 666 (97%; 95% CI, 96 to 98) were seropositive for yellow fever antibody. The distribution of titers among the participants who were seronegative for yellow fever antibody at baseline varied significantly among age groups at 1 month and at 1 year (P<0.001 for both comparisons).

CONCLUSIONS: A fractional dose of the 17DD yellow fever vaccine was effective at inducing seroconversion in participants who were seronegative at baseline. Titers remained above the threshold for seropositivity at 1 year after vaccination in nearly all participants who were seropositive at 1 month after vaccination. These findings support the use of fractional-dose vaccination for outbreak control. (Funded by the U.S. Agency for International Development and the Centers for Disease Control and Prevention.).

Medienart:

E-Artikel

Erscheinungsjahr:

2019

Erschienen:

2019

Enthalten in:

Zur Gesamtaufnahme - volume:381

Enthalten in:

The New England journal of medicine - 381(2019), 5 vom: 01. Aug., Seite 444-454

Sprache:

Englisch

Beteiligte Personen:

Casey, Rebecca M [VerfasserIn]
Harris, Jennifer B [VerfasserIn]
Ahuka-Mundeke, Steve [VerfasserIn]
Dixon, Meredith G [VerfasserIn]
Kizito, Gabriel M [VerfasserIn]
Nsele, Pierre M [VerfasserIn]
Umutesi, Grace [VerfasserIn]
Laven, Janeen [VerfasserIn]
Kosoy, Olga [VerfasserIn]
Paluku, Gilson [VerfasserIn]
Gueye, Abdou S [VerfasserIn]
Hyde, Terri B [VerfasserIn]
Ewetola, Raimi [VerfasserIn]
Sheria, Guylain K M [VerfasserIn]
Muyembe-Tamfum, Jean-Jacques [VerfasserIn]
Staples, J Erin [VerfasserIn]

Links:

Volltext

Themen:

Antibodies, Neutralizing
Antibodies, Viral
Clinical Study
Journal Article
Multicenter Study
Research Support, U.S. Gov't, P.H.S.
Yellow Fever Vaccine

Anmerkungen:

Date Completed 07.08.2019

Date Revised 02.09.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1056/NEJMoa1710430

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM281023360