Table 1. Study components, timeline, and sample size per study activity.

Study Component	Timeline	Sample Size	Intervention/Activity
Part A: Vaccination	2018 Dec-2019 Feb	All eligible 8,000~9,000* schoolgirls (<15 years old) in Grade 8 per province	Udon Thani: single-dose HPV vaccine regimen Buri Ram: two-dose HPV vaccine regimen 6 months apart
		N = 1,500 for SBQ
		N = 200 (pre-vaccine serology)
Part B: Baseline CSS	2018 Dec-2019 Feb	G10/V1: N = 2,600 schoolgirls per province	SBQ and HPV urine prevalence
		G12/V3: N = 2,000 schoolgirls per province
Part C: Year 2 CSS	2020 Dec-2021 Feb	G10/V1: N = 2,600 schoolgirls per province	SBQ and HPV urine prevalence
		N = 200 (serology)
Part D: Year 4 CSS	2022 Dec-2023 Feb	G12/V3: N = 2,000 schoolgirls per province	SBQ and HPV urine prevalence
		N = 200 (serology)

*Approximate number of Grade 8 schoolgirls that will be eligible and offered vaccination