tetano
Editor, Senior Moderator
Expert Rev Vaccines. 2019 Dec 25. doi: 10.1080/14760584.2020.1709827. [Epub ahead of print] [h=1]In-depth phylogenetic analysis of the hemagglutinin gene of influenza A(H3N2) viruses circulating during the 2016-2017 season revealed egg-adaptive mutations of vaccine strains.[/h]
Galli C[SUP]1[/SUP], Orsi A[SUP]2,[/SUP][SUP]3[/SUP], Pariani E[SUP]1,[/SUP][SUP]3[/SUP], Lai PL[SUP]2,[/SUP][SUP]3[/SUP], Guarona G[SUP]2[/SUP], Pellegrinelli L[SUP]1[/SUP], Ebranati E[SUP]4[/SUP], Icardi G[SUP]2,[/SUP][SUP]3[/SUP], Panatto D[SUP]2,[/SUP][SUP]3[/SUP].
[h=3]Author information[/h] 1 Department of Biomedical Sciences for Health, University of Milan, Milan, Italy. 2 Department of Health Sciences, University of Genoa, Genoa, Italy. 3 Interuniversity Research Center on Influenza and Other Transmissible Infections (CIRI-IT), Genoa, Italy. 4 Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Milan, Italy.
[h=3]Abstract[/h] 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 candidate vaccine virus (CVV).Methods: 162 HA1 sequences of H3N2 viruses identified during the 2016-2017 season were phylogenetically analysed and compared with egg-/cell-derived CVV. The predicted vaccine efficacy (pVE) of egg-/cell-derived CVV against field strains was quantified by P[SUB]epitope[/SUB] 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.
[h=4]KEYWORDS:[/h] cell-derived vaccine; egg-adaptive mutations; egg-derived vaccine; influenza A(H3N2) virus; influenza vaccine; virus evolution
PMID: 31875483 DOI: 10.1080/14760584.2020.1709827
Galli C[SUP]1[/SUP], Orsi A[SUP]2,[/SUP][SUP]3[/SUP], Pariani E[SUP]1,[/SUP][SUP]3[/SUP], Lai PL[SUP]2,[/SUP][SUP]3[/SUP], Guarona G[SUP]2[/SUP], Pellegrinelli L[SUP]1[/SUP], Ebranati E[SUP]4[/SUP], Icardi G[SUP]2,[/SUP][SUP]3[/SUP], Panatto D[SUP]2,[/SUP][SUP]3[/SUP].
[h=3]Author information[/h] 1 Department of Biomedical Sciences for Health, University of Milan, Milan, Italy. 2 Department of Health Sciences, University of Genoa, Genoa, Italy. 3 Interuniversity Research Center on Influenza and Other Transmissible Infections (CIRI-IT), Genoa, Italy. 4 Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Milan, Italy.
[h=3]Abstract[/h] 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 candidate vaccine virus (CVV).Methods: 162 HA1 sequences of H3N2 viruses identified during the 2016-2017 season were phylogenetically analysed and compared with egg-/cell-derived CVV. The predicted vaccine efficacy (pVE) of egg-/cell-derived CVV against field strains was quantified by P[SUB]epitope[/SUB] 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.
[h=4]KEYWORDS:[/h] cell-derived vaccine; egg-adaptive mutations; egg-derived vaccine; influenza A(H3N2) virus; influenza vaccine; virus evolution
PMID: 31875483 DOI: 10.1080/14760584.2020.1709827