Table 2b:

Incidence of persistent HPV 16/18/31/33/45/52/58 and Vaccine Efficacy by Month 18 (mITT Cohort)

						95% Confidence Interval*		Statistical Comparisons***
Arm	Enrolled (n)	HPV 16/18/31/ 33/45/52/ 58 naïve^ (mITT) (n)	Incident persistent HPV 16/18/31/3 3/45/52/58 (n)	Woman- years of Follow- up**	Incidence of persistent HPV 16/18/31/33/4 5/52/58 per 100 Woman- years	Lower Bound	Upper Bound	Comparison	Vaccine Efficacy	95% CI	P-value (Log- rank)
Nonavalent HPV	758	325	4	389.18	1.03	0.28	2.63	Nonavalent v. Meningococcal	88.9%	(68.5%, 96.1%)	<.0001
Meningococcal	757	290	29	307.81	9.42	6.31	13.53

^*Exact 95% confidence interval for incidence rate computed using the Poisson distribution.

^**Follow-up time amongst women HPV 16/18/31/33/45/52/58 DNA-negative at month 0 and month 3, and antibody-negative at month 0.

^***Hazard ratios with 95% confidence intervals are estimated using a single Cox proportional hazards regression model with a three-way class variable for vaccine arm. The model is stratified by site, with Efron method for handling ties, and vaccine arm was the only covariate. Vaccine efficacy and 95% CI computed from the hazard ratio as 100*(1-HR). P-value (log-rank) computed for each comparison using the log-rank test.

^{^}HPV 16/18/31/33/45/52/58 naïve participants are those who tested negative for HPV 16/18/31/33/45/52/58 antibodies at enrollment and negative for HPV 16/18/31/33/45/52/58 DNA at enrollment and month three.