This randomized, open-label, active-controlled trial will assess humoral immune responses to a single dose of 2019-20 recombinant hemagglutinin quadrivalent influenza vaccines (RIV4) compared with standard egg-based unadjuvanted quadrivalent influenza vaccines (IIV4) among healthcare personnel (HCP) vaccinated during the previous 2018-19 season with IIV4. The trial will be conducted at two hospital sites in Israel during the 2019-20 influenza season among HCP who were enrolled in the Study of Healthcare Personnel with Influenza and other Respiratory Viruses in Israel (SHIRI).
This is a randomized, open-label study design. Starting in July 2019, approximately 550 to 700 HCP from two hospitals (275-350 per hospital site) in Israel will be enrolled. Following completion of a written consent form, participants will complete an enrollment survey and grant permission for review of information collected during the SHIRI study, including vaccination status and immune response during the SHIRI study years. Participants will complete an enrollment survey and grant permission to include and integrate information collected during the SHIRI study into the current study's data, including health history, influenza vaccination history, and immune response to vaccination during the SHIRI study years. HCP will be randomly assigned 1:1 to receive a single dose of IIV4 licensed in Israel (expected to be Vaxigrip® Quadrivalent, 15µg of HA per strain) or RIV4 (Flublok® Quadrivalent by Sanofi Pasteur, 45µg of HA per strain) during August-October of 2019. Adverse events following vaccination will be monitored and documented. Blood specimens will be collected prior to vaccination and approximately 28 days after to evaluate immune responses to vaccination. Eligible HCP who were already vaccinated with Vaxigrip, the vaccine that is routinely available in Israel, at the time they are approached to join the study, will be invited to join the study as part of the Vaxigrip arm. Like randomized participants, participants who were vaccinated with Vaxigrip outside the study will complete a written consent form, an enrollment survey and grant permission for review of information collected during the SHIRI study, including vaccination status and immune response during the SHIRI study years. As part of the consent form, participants will record the estimated date that they received the vaccine, and the location, and will authorize study staff to verify the date of current-year Vaxigrip vaccination in the Clalit EMR and with the hospital vaccination staff. Participants will complete an enrollment survey and grant permission to include and integrate information collected during the SHIRI study into the current study's data, including health history, influenza vaccination history, and immune response to vaccination during the SHIRI study years. Blood specimens will be collected approximately 28 days after to evaluate immune responses to vaccination.
0.5 mL intramuscular dose of Flublok
0.5 mL intramuscular dose of Vaxigrip
Soroka Medical Center
Beersheba, Israel
Rabin Medical Center-Beilinson
Petah Tikva, Israel
Post-vaccination Geometric Mean Titer Against Influenza Virus A/H1N1
The geometric mean of antibody titers following a single dose of RIV4 or IIV4 as measured by hemagglutination inhibition (HI) for influenza virus A/H1N1
Time frame: Day 28 days after vaccination
Geometric Mean Titer Ratio (GMR) Against Influenza Virus A/H1N1
The ratio of the pre- vs. post-vaccination titer against influenza virus A/H1N1 following a single dose of RIV4 versus IIV4.
Time frame: 0 to 28 days after vaccination
Post-vaccination Geometric Mean Titer Against Egg-grown Influenza Virus A/H3N2
The geometric mean of antibody titers following a single dose of RIV4 or IIV4 as measured by hemagglutination inhibition (HI) for egg-grown influenza virus A/H3N2
Time frame: Day 28 days after vaccination
Geometric Mean Titer Ratio (GMR) Against Egg-grown Influenza Virus A/H3N2
The ratio of the pre- vs. post-vaccination titer against egg-grown influenza virus A/H3N2 following a single dose of RIV4 versus IIV4.
Time frame: 0 to 28 days after vaccination
Post-vaccination GMT Against Cell-grown Influenza Virus A/H3N2
The geometric mean of antibody titers following a single dose of RIV4 or IIV4 as measured by hemagglutination inhibition (HI) for cell-grown influenza virus A/H3N2
Time frame: Day 28 days after vaccination
Geometric Mean Titer Ratio (GMR) Against Cell-grown Influenza Virus A/H3N2
The ratio of the pre- vs. post-vaccination titer against cell-grown influenza virus A/H3N2 following a single dose of RIV4 versus IIV4.
Time frame: 0 to 28 days after vaccination
Post-vaccination Geometric Mean Titer Against Influenza B(Victoria)
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Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
SINGLE
Enrollment
577
The geometric mean of antibody titers following a single dose of RIV4 or IIV4 as measured by hemagglutination inhibition (HI) for Influenza B(Victoria)
Time frame: Day 28 days after vaccination
Geometric Mean Titer Ratio (GMR) Against Influenza B(Victoria)
The ratio of the pre- vs. post-vaccination titer against Influenza B(Victoria) following a single dose of RIV4 versus IIV4.
Time frame: 0 to 28 days after vaccination
Post-vaccination Geometric Mean Titer Against Influenza B(Yamagata)
The geometric mean of antibody titers following a single dose of RIV4 or IIV4 as measured by hemagglutination inhibition (HI) for Influenza B(Yamagata)
Time frame: Day 28 days after vaccination
Geometric Mean Titer Ratio (GMR) Against Influenza B(Yamagata)
The ratio of the pre- vs. post-vaccination titer against Influenza B(Yamagata) following a single dose of RIV4 versus IIV4.
Time frame: 0 to 28 days after vaccination