17DD Yellow Fever Revaccination and Heightened Long-Term Immunity in Populations of Disease-Endemic Areas, Brazil

• Main Authors: Olindo Assis Martins-Filho, Vanessa Peruhype-Magalhāes, Jordana Grazziela Coelho-dos-Reis, Lis Ribeiro Antonelli, Christiane Costa-Pereira, Elaine Speziali, Laise Rodrigues Reis, Jandira Aparecida Lemos, José Geraldo Leite Ribeiro, Luiz Antônio Bastos Camacho, Maria de Lourdes de Sousa Maia, Sheila Maria Barbosa de Lima, Marisol Simões, Reinaldo de Menezes Martins, Akira Homma, Luiz Cosme Cota Malaquias, Pedro Luiz Tauil, Pedro Fernando Costa Vasconcelos, Alessandro Pecego Martins Romano, Carla Magda Domingues, Andréa Teixeira-Carvalho, Ana Carolina Campi-Azevedo
• Format: Article
• Language: English
• Published: Centers for Disease Control and Prevention 2019-08-01
• Series: Emerging Infectious Diseases
• Subjects: yellow fever; 17DD vaccine; neutralizing antibodies; memory CD8+ T-cells; vector-borne infections; viruses
• Online Access: https://wwwnc.cdc.gov/eid/article/25/8/18-1432_article

We evaluated the duration of neutralizing antibodies and the status of 17DD vaccine–specific T- and B-cell memory following primary and revaccination regimens for yellow fever (YF) in Brazil. We observed progressive decline of plaque-reduction neutralization test (PRNT) seropositivity and of the levels of effector memory CD4+ and CD8+ T cells, as well as interferon-γ+CD8+ T cells, 10 years after primary vaccination. Revaccination restored PRNT seropositivity as well as the levels of effector memory CD4+, CD8+, and interferon-γ+CD8+ T cells. Moreover, secondary or multiple vaccinations guarantee long-term persistence of PRNT positivity and cell-mediated memory 10 years after booster vaccination. These findings support the relevance of booster doses to heighten the 17DD-YF–specific immune response to guarantee the long-term persistence of memory components. Secondary or multiple vaccinations improved the correlates of protection triggered by 17DD-YF primary vaccination, indicating that booster regimens are needed to achieve efficient immunity in areas with high risk for virus transmission.