Table 2. Published estimates of HPV vaccine efficacy among SPDN cohorts.

Year	Author	Study	Endpoint	Efficacy	95% CI	No. (SPDN)
2009	Olsson et al. [36]	V501–007/FUTURE I/II	HPV-6/11/16/18 related CIN1+	VE 100%	28.7%–100%	2,526
2011	Castellsagué et al. [37]	FUTURE III	HPV6/11/16/18 infection or CIN	VE 66.9%	4.3%–90.6%	1,019
2012	Szarewski et al. [25]	PATRICIA	6mPI	VE 72.3%	53.0%–84.5%	3,421
		PATRICIA	CIN1+	VE 67.2%	10.9%–89.9%	3,487
		PATRICIA	CIN2+	VE 68.8%	−28.3%–95.0%	3,487
2014	Skinner et al. [38]	VIVIANE	HPV16/18 associated 6mPI/CIN1+	VE 86.4%	30.1%–99.0%	NR
2016	Beachler et al. [34]	Costa Rica Vaccine Study	Cervical HPV point prevalence at 4 years	VE 76.5%	54.6%–88.8%	1,384
2018	Arbyn et al. [6]	Future II/PATRICIA	CIN2+	RR 0.19	0.09–0.77	4,506

6mPI, 6-month persistent infection; CIN, cervical intraepithelial neoplasia; HPV, human papillomavirus; NR, not reported; RR, relative risk; SPDN, seropositive, DNA negative; VE, vaccine efficacy.