Objectives: The authors conducted an in-depth phylogenetic analysis of the hemagglutinin (HA) gene of A(H3N2) identified during the 2016-2017 season to compare the circulating strains with both the egg-derived and cell-derived 2016-2017 candidate vaccine virus (CVV). Methods: 162 HA1 sequences of H3N2 viruses identified during the 2016-2017 season were phylogenetically analyzed and compared with egg-/cell-derived CVV. The predicted vaccine efficacy (pVE) of egg-/cell-derived CVV against field strains was quantified by Pepitope model. Results: All H3N2 belonged to 3C.2a genetic clade, most (80.2%) to 3C.2a1 sub-clade. Several H3N2 variants circulated in the 2016-2017 season. HA sequences of field H3N2 strains displayed greater identity with cell-derived CVV than with egg-derived CVV. The amino acid substitutions in positions 160 and 194 identified in egg-derived CVV affected the pVE, which was lower for egg-derived CVV than for cell-derived CVV.Conclusions: The results suggested that reduced vaccine effectiveness observed in 2016-2017 season was probably due to changes in the HA of vaccine strains acquired upon adaptation in eggs, which are the basis of most manufacturing systems currently used globally. Egg-free vaccine manufacturing systems would be advisable to improve the effectiveness of influenza vaccines.
Objectives: The authors conducted an in-depth phylogenetic analysis of the hemagglutinin (HA) gene of A(H3N2) identified during the 2016-2017 season to compare the circulating strains with both the egg-derived and cell-derived 2016-2017 candidate vaccine virus (CVV). Methods: 162 HA1 sequences of H3N2 viruses identified during the 2016-2017 season were phylogenetically analyzed and compared with egg-/cell-derived CVV. The predicted vaccine efficacy (pVE) of egg-/cell-derived CVV against field strains was quantified by Pepitope model. Results: All H3N2 belonged to 3C.2a genetic clade, most (80.2%) to 3C.2a1 sub-clade. Several H3N2 variants circulated in the 2016-2017 season. HA sequences of field H3N2 strains displayed greater identity with cell-derived CVV than with egg-derived CVV. The amino acid substitutions in positions 160 and 194 identified in egg-derived CVV affected the pVE, which was lower for egg-derived CVV than for cell-derived CVV.Conclusions: The results suggested that reduced vaccine effectiveness observed in 2016-2017 season was probably due to changes in the HA of vaccine strains acquired upon adaptation in eggs, which are the basis of most manufacturing systems currently used globally. Egg-free vaccine manufacturing systems would be advisable to improve the effectiveness of influenza vaccines.
Authors: Sara Boccalini; Elena Pariani; Giovanna Elisa Calabrò; Chiara DE Waure; Donatella Panatto; Daniela Amicizia; Piero Luigi Lai; Caterina Rizzo; Emanuele Amodio; Francesco Vitale; Alessandra Casuccio; Maria Luisa DI Pietro; Cristina Galli; Laura Bubba; Laura Pellegrinelli; Leonardo Villani; Floriana D'Ambrosio; Marta Caminiti; Elisa Lorenzini; Paola Fioretti; Rosanna Tindara Micale; Davide Frumento; Elisa Cantova; Flavio Parente; Giacomo Trento; Sara Sottile; Andrea Pugliese; Massimiliano Alberto Biamonte; Duccio Giorgetti; Marco Menicacci; Antonio D'Anna; Claudia Ammoscato; Emanuele LA Gatta; Angela Bechini; Paolo Bonanni Journal: J Prev Med Hyg Date: 2021-09-10
Authors: Joan Puig-Barberà; Sonia Tamames-Gómez; Pedro Plans-Rubio; José María Eiros-Bouza Journal: Int J Environ Res Public Health Date: 2022-01-12 Impact factor: 3.390