Low Influenza Vaccine Effectiveness Against A(H3N2)-Associated Hospitalizations in 2016–2017 and 2017–2018 of the Hospitalized Adult Influenza Vaccine Effectiveness Network (HAIVEN)
Emily T. Martin, Caroline Cheng, Joshua G. Petrie, Elif Alyanak, Manjusha Gaglani, Donald B. Middleton, Shekhar Ghamande, Fernanda P. Silveira, Kempapura Murthy, Richard K. Zimmerman, Arnold S. Monto, Christopher Trabue, H. Keipp Talbot, Jill M. Ferdinands, HAIVEN Study Investigators, Lois Lamerato, Adam S. Lauring, Ryan E. Malosh, Kempapura Murthy, Tresa McNeal, Kevin Chang, Heath D. White, Alejandro C. Arroliga, Laurel Kilpatrick, Meredith Wimberly, Victor Escobedo, JoAnn Nichols, Lydia Clipper, Chandni Raiyani, Wencong Chen, Anne Robertson, Arundhati Rao, Robert Fader, Kimberly Walker, Marcus Volz, Kailey Hughes, Sean Saul, Lori Stiefel, Michael Susick, Balasubramani K Goundappa, Charles R. Rinaldo, John Williams, Monika Johnson, Julie Gealey, Heather Eng, Melissa Saul
Abstract
BACKGROUND: The 2016-2017 and 2017-2018 influenza seasons were notable for the high number of hospitalizations for influenza A(H3N2) despite vaccine and circulating strain match. METHODS: We evaluated vaccine effectiveness (VE) against hospitalization in the test-negative HAIVEN study. Nasal-throat swabs were tested by quantitative reverse transcription polymerase chain reaction (RT-PCR) for influenza and VE was determined based on odds of vaccination by generalized estimating equations. Vaccine-specific antibody was measured in a subset of enrollees. RESULTS: A total of 6129 adults were enrolled from 10 hospitals. Adjusted VE against A(H3N2) was 22.8% (95% confidence interval [CI], 8.3% to 35.0%), pooled across both years and 49.4% (95% CI, 34.3% to 61.1%) against B/Yamagata. In 2017-2018, the A(H3N2) VE point estimate for the cell-based vaccine was 43.0% (95% CI, -36.3% to 76.1%; 56 vaccine recipients) compared to 24.0% (95% CI, 3.9% to 39.9%) for egg-based vaccines. Among 643 with serology data, hemagglutinin antibodies against the egg-based A(H3N2) vaccine strain were increased in influenza-negative individuals. CONCLUSIONS: Low VE for the A/Hong Kong/4801/2014 vaccine virus in both A(H3N2) seasons emphasizes concerns for continued changes in H3N2 antigenic epitopes, including changes that may impact glycosylation and ultimately reduce VE.