tetano
Editor, Senior Moderator
J Infect Dis. 2019 Feb 4. doi: 10.1093/infdis/jiz049. [Epub ahead of print]
[h=1]Antibodies against egg- and cell-grown influenza A(H3N2) viruses in adults hospitalized during the 2017-2018 season.[/h] Levine MZ[SUP]1[/SUP], Martin ET[SUP]2[/SUP], Petrie JG[SUP]2[/SUP], Lauring AS[SUP]3[/SUP], Holiday C[SUP]1[/SUP], Jefferson S[SUP]1[/SUP], Fitzsimmons WJ[SUP]3[/SUP], Johnson E[SUP]2[/SUP], Ferdinands JM[SUP]1[/SUP], Monto AS[SUP]2[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]Background:[/h] Influenza vaccine effectiveness was low in 2017-2018, yet circulating A(H3N2) viruses were antigenically similar to cell-grown vaccine strains. Notably, most influenza vaccines are egg-propagated.
[h=4]Methods:[/h] Serum was collected shortly after illness onset from 15 A(H3N2) infected cases and 15 uninfected hospitalized adults. Geometric mean titers against egg- and cell-grown A/Hong Kong/4801/2014 A(H3N2) vaccine strains and representative circulating viruses (including A/Washington/16/2017) were determined by microneutralization (MN). Independent effects of strain-specific titers on susceptibility were estimated by logistic regression.
[h=4]Results:[/h] MN titers against egg-A/Hong Kong were significantly higher among vaccinated individuals (173 vs 41; p=0.01). In unadjusted models, a 2-fold increase in titers against egg-A/Hong Kong was not significantly protective (29% reduction; p=0.09), but a similar increase in cell-A/Washington titer (3C.2a2) was protective (60% reduction; p=0.02). Higher egg-A/Hong Kong titers were not significantly associated with infection, when adjusted for titers against A/Washington (15% reduction; p=0.61). A 54% reduction of odds of infection was observed with a 2-fold increase in A/Washington (not significant), adjusted for egg-A/Hong Kong titer.
[h=4]Conclusion:[/h] Individuals vaccinated in 2017-2018 had high antibody titers against the egg-adapted vaccine strain and lower titers against circulating viruses. Titers against circulating, but not egg-adapted strains, were correlated with protection.
PMID: 30721982 DOI: 10.1093/infdis/jiz049
[h=1]Antibodies against egg- and cell-grown influenza A(H3N2) viruses in adults hospitalized during the 2017-2018 season.[/h] Levine MZ[SUP]1[/SUP], Martin ET[SUP]2[/SUP], Petrie JG[SUP]2[/SUP], Lauring AS[SUP]3[/SUP], Holiday C[SUP]1[/SUP], Jefferson S[SUP]1[/SUP], Fitzsimmons WJ[SUP]3[/SUP], Johnson E[SUP]2[/SUP], Ferdinands JM[SUP]1[/SUP], Monto AS[SUP]2[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]Background:[/h] Influenza vaccine effectiveness was low in 2017-2018, yet circulating A(H3N2) viruses were antigenically similar to cell-grown vaccine strains. Notably, most influenza vaccines are egg-propagated.
[h=4]Methods:[/h] Serum was collected shortly after illness onset from 15 A(H3N2) infected cases and 15 uninfected hospitalized adults. Geometric mean titers against egg- and cell-grown A/Hong Kong/4801/2014 A(H3N2) vaccine strains and representative circulating viruses (including A/Washington/16/2017) were determined by microneutralization (MN). Independent effects of strain-specific titers on susceptibility were estimated by logistic regression.
[h=4]Results:[/h] MN titers against egg-A/Hong Kong were significantly higher among vaccinated individuals (173 vs 41; p=0.01). In unadjusted models, a 2-fold increase in titers against egg-A/Hong Kong was not significantly protective (29% reduction; p=0.09), but a similar increase in cell-A/Washington titer (3C.2a2) was protective (60% reduction; p=0.02). Higher egg-A/Hong Kong titers were not significantly associated with infection, when adjusted for titers against A/Washington (15% reduction; p=0.61). A 54% reduction of odds of infection was observed with a 2-fold increase in A/Washington (not significant), adjusted for egg-A/Hong Kong titer.
[h=4]Conclusion:[/h] Individuals vaccinated in 2017-2018 had high antibody titers against the egg-adapted vaccine strain and lower titers against circulating viruses. Titers against circulating, but not egg-adapted strains, were correlated with protection.
PMID: 30721982 DOI: 10.1093/infdis/jiz049