Table 2.

Predicted duration ensuring that 95% of women would still have anti-HPV–16 and anti-HPV–18 antibody levels above natural infection levels in women aged 15–25, 26–45, and 46–55 years in the present study, and in women aged 15–25 years in a previous study (NCT00689741 and NCT00120848)⁴¹

Antigen	Antibody levels induced by natural infection (EU/mL)*	Model	Duration ensuring antibody levels above those induced by natural infection in 95% participants (years)
			Current study			Previous modelling study**
			15–25 years old***	26–45 years old***	46–55 years old***	15–25 years old***
HPV–16	29.8	Modified power-law	Lifelong	Lifelong	Lifelong	Lifelong
		Piecewise	40.08	16.9	12.1	26.7
HPV–18	22.6	Modified power-law	Lifelong	Lifelong	4.3 years	Lifelong
		Piecewise	19.2	9.0	5.1	19.9

^*Measured in a previous study in women who cleared natural infection.^30,31

^**Women aged 15–25 years in a previous study (NCT00689741 and NCT00120848).⁴¹

^***Age ranges indicate the ages of women at the time of the first vaccination dose.