Table 5.

Design of trials with a focus on influenza vaccination.

Reference	Setting/country/population	Study design	Experimental arm vs control arm(s), n	Intervention description and control	Duration
Moniz et al (2013) [47]	Prenatal clinic/Pittsburgh, Pennsylvania, United States/<28 weeks’ gestation	RCTa	Intervention (104) vs control (100)	12 weekly text messages with information about the benefits and safety of influenza vaccine in pregnancy vs control messages about general pregnancy health alone	12 weeks, up to 6 weeks postpartum
Yudin (2017) [48]	Prenatal clinic/Toronto, Canada/any gestational age	RCT	Intervention (153) vs control (164)	Text messages twice weekly × 4 weeks emphasizing pregnant women’s susceptibility to influenza, effectiveness of vaccine, safety of vaccines, and that vaccines are recommended for pregnant women vs usual care	Until 6 weeks postpartum

^aRCT: randomized controlled trial.