Randomised immunogenicity trial comparing 2019-2020 recombinant and egg-based influenza vaccines among frequently vaccinated healthcare personnel in Israel.
Ashley L Fowlkes, Alon Peretz, David Greenberg, Avital Hirsch, Emily T Martin, Min Z Levine, Laura Edwards, Sarah Radke, Adam S Lauring, Jill M Ferdinands, Chao Zhang, Young M Yoo, Jacob Dreiher, Gabriella Newes-Adeyi, Eduardo Azziz-Baumgartner, Alicia M Fry, Arnold S Monto, Ran Balicer, Mark G Thompson, Mark A Katz
Author Information
Ashley L Fowlkes: Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA. Electronic address: Ahl4@cdc.gov.
Alon Peretz: Rabin Medical Center, Clalit Health Services, Beilinson Campus, Petah Tikva, Israel.
David Greenberg: Soroka University Medical Center, Clalit Health Services, Be'er Sheva, Israel.
Avital Hirsch: Clalit Research Institute, Innovation Division, Clalit Health Services, Tel Aviv, Israel.
Emily T Martin: School of Public Health, University of Michigan, Ann Arbor, Michigan, USA.
Min Z Levine: Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Laura Edwards: Abt Associates, Inc., Atlanta, Georgia, USA.
Sarah Radke: National Institute of Health Innovation, University of Auckland, Auckland, New Zealand.
Adam S Lauring: School of Public Health, University of Michigan, Ann Arbor, Michigan, USA.
Jill M Ferdinands: Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Chao Zhang: Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Young M Yoo: Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Jacob Dreiher: Soroka University Medical Center, Clalit Health Services, Be'er Sheva, Israel.
Gabriella Newes-Adeyi: Abt Associates, Inc., Atlanta, Georgia, USA.
Eduardo Azziz-Baumgartner: Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Alicia M Fry: Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Arnold S Monto: School of Public Health, University of Michigan, Ann Arbor, Michigan, USA.
Ran Balicer: Clalit Research Institute, Innovation Division, Clalit Health Services, Tel Aviv, Israel.
Mark G Thompson: Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Mark A Katz: Clalit Research Institute, Innovation Division, Clalit Health Services, Tel Aviv, Israel.
OBJECTIVES: Trivalent inactivated influenza vaccine effectiveness was low in a prospective cohort of healthcare personnel (HCP) in Israel from 2016 to 2019. We conducted a randomised immunogenicity trial of quadrivalent recombinant influenza vaccine (RIV4) and standard-dose inactivated influenza vaccine (IIV4) among frequently and infrequently vaccinated previous cohort participants. METHODS: From October 2019 to January 2020, we enrolled and randomly allocated HCP from two Israeli hospitals to receive IIV4 or RIV4. Hemagglutination inhibition (HAI) antibody titres against 2019-2020 vaccine reference influenza viruses were compared between vaccine groups using geometric mean titre (GMT) ratios from sera collected one-month post-vaccination and by frequency of vaccination in the past 5 years (>2 vs ���2). RESULTS: Among 415 HCP, the GMT ratio comparing RIV4 to IIV4 was 2.0 (95% confidence interval [CI] 1.7-2.7) for A(H1N1)pdm09, 1.6 (95% CI: 1.3-1.9) for A(H3N2), 1.8 (95% CI: 1.4-2.2) for B(Yamagata), and 1.1 (95% CI: 0.9-1.4) for B(Victoria). Similarly, RIV4 elicited higher HAI titres than IIV4 against all 2019-2020 vaccine reference viruses except B(Victoria) among infrequently and frequently vaccinated HCP (lower bound of GMT ratio 95% CIs ���1.0). CONCLUSION: RIV4 had improved immunogenicity for influenza vaccine strains among both infrequent and frequent vaccinees compared to standard-dose IIV4. CLINICAL TRIALS REGISTRATION: NCT04523324.
