Table 2. Characteristics of IIV3-cc studies included in the systematic review.

Study	Design (vaccine)	Study population	Outcomes
Ambrozaitis et al. (2009)	• RCT • 2005–2006 influenza season • (IIV3-cc versus egg-based IIV3)	• Healthy adults 18–60 years of age • IIV3-cc (n=1,028) • Egg-based IIV3 (n=171)	• AEs within seven days of vaccination
Szymczakiewicz-Multanowska et al. (2009) NCT00492063	• Phase III, observer blind RCT • 2004–2005 influenza season • (IIV3-cc vs egg-based IIV3)	• Healthy adults 18 years of age and older • IIV3-cc:     • 18–60 years of age (n=652)     • 61 years of age and older (n=678) • Egg-based IIV3:     • 18–60 years of age (n=648)     • 61 years of age and older (n=676)	• AEs within seven days of vaccination
Nolan et al. 2016	• Phase III, observer blind RCT • 2013–2014 influenza season • (IIV3-cc vs egg-based IIV3)	• Healthy children and adolescents 4–17 years of age • IIV3-cc (n=1,372) • Egg-based IIV3 (n=683)	• AEs within seven days of vaccination
Vesikari et al. (2012)	• Phase II/III, observer-blind RCT • October 2007–July 2008 • (IIV3-cc vs egg-based IIV3)	• Healthy children and adolescents 3–17 years of age • IIV3-cc two doses 3–8 years of age (n=1,599) • IIV3-cc single dose 9–17 years of age (n=652) • Egg-based IIV3 3–8 years of age (n=1,013) • Egg-based IIV3 9–17 years of age (n=316)	• AEs within seven days of vaccination
Frey et al. (2010) NCT00630331	• Observer-blind RCT • 2007–2008 influenza season • (IIV3-cc vs egg-based IIV3)	• Healthy adults 18–49 years of age • IIV3-cc (n=3,813) • Egg-based IIV3 (n=3,669) • Placebo (n=3,894)	• AEs within seven days of vaccination
Loebermann et al. (2019) NCT01880697	• Phase III open-label, single-arm, study • 2013–2014 influenza season • (IIV3-cc)	• Healthy adults • IIV3-cc:     • 18–60 years age (n=63)     • 61 years age and older (n=63)	• AEs following vaccination
Moro et al. (2015)	• Clinical review of cases identified through VAERS • 2013–2014, 2014–2015 influenza seasons • (IIV3-cc)	• Persons vaccinated with IIV3-cc during July 1, 2013 through March 31, 2015 (reports received by April 30, 2015); excluding non-US reports • Total reports reviewed: n=629 • Persons vaccinated with IIV3-cc July 1, 2013–March 31, 2015 (reports received by April 30, 2015); excluding non-US reports • Reports with an AE:     • n=309     • during 2013–2014 influenza season (n=389)     • during 2014–2015 influenza season (n=240)	• AEs following vaccination

Abbreviations: AE, adverse event; IIV3, trivalent inactivated influenza vaccine; IIV3-cc, cell-culture based trivalent inactivated influenza vaccine; NCT, National clinical trial number; RCT, randomized controlled trial; US, United States; VAERS, Vaccine Adverse Event Reporting System