Table 3.

Study events and activities

	Arm 1 (standard of care)	Arm 2 (reminders only)	Arm 3 (reminders + incentive)
Pregnancy	Recruitment and enrollment during the last trimester (EDD within 3 months). In-person baseline survey
Birth		Phone-based documentation of birth date and birth outcome within 14 days of EDD
Vaccination V0 At birth (t 0 ) BCG OPV(0)		Phone-based confirmation of V0 visit at t0+14d. If not vaccinated, follow up every 14 days Updates to t6w, t10w, and t14w as needed
			Full amount if V0 visit by t0+14d Half amount if V0 visit between t0+14d and t0+28d None after t0+28d
Vaccination V1 6 weeks (t6w) OPV(1) Penta(1) PCV(1) Rota(1)		Reminders at t6w-7d and t6w-1d Phone-based confirmation of V1 visit at t6w+14d. If not vaccinated, follow up every 14 days Updates to t10w and t14w as needed
			Full amount if V1 visit by t6w+14d Half amount if V1 visit between t6w+14d and t6w+28d None after t6w+28d
Vaccination V2 10 weeks (t 10w ) OPV(2) Penta(2) PCV(2) Rota(2)		Reminders at t10w-7d and t10w-1d Phone based confirmation of V2 visit at t10w+14d. If not vaccinated, follow up every 14 days. Updates to t14w as needed
			Full amount if V2 visit by t10w+14d Half amount if V2 visit between t10w+14d and t10w+28d None after t10w+28d
Vaccination V3 14 weeks (t14w) OPV(3) Penta(3) PCV(3)		Reminders at t14w-7d and t14w-1d Phone based confirmation of V3 visit at t14w+14d. If not vaccinated, follow up every 14 days.
			Full amount if V3 visit by t14w+14 days Half amount if V3 visit between t10w+14d and t10w+28d None after t14w+28d
Exit survey	In-person survey to assess barriers to vaccinations, acceptability of reminders (arms 2 and 3) and incentives (arm 3), and document vaccination coverage and timeliness using government-issued vaccination cards

Abbreviations: EDD = expected date of delivery; w = weeks; d = days; t = time; BCG, OPV, Penta, PCV, Rota: see Table 1