Table 1.

Summary of published studies of HPV vaccine impact on biologic endpoints

Country (year vaccine introduced)	Data source and/or location	First author, publication year, [reference no.]	Population	Study design	Resultsb
HPV infectiona
Australia (2007)	Family planning clinics in Victoria	Tabrizi, 2012 [10]	Females 18–24 years	Ecologic, compared pre- to postvaccine periods	VT prevalence decreased from 28.7% (2005–2007) to 5.0% (vaccinated, 2010–2011) and 15.8% (unvaccinated, 2010–2011)
USA (2006)	Adolescent/community health clinics in Ohio	Kahn, 2012 [9]	Females 13–26 years	Compared pre- to postvaccine periods by vaccination status	VT prevalence decreased from 31.8% (2006–2007) to 9.9% (vaccinated, 2009–2010) and 15.4% (unvaccinated, 2009–2010)
	Urban STD/community health clinics in Indiana	Cummings, 2012 [8]	Females 14–17 years	Ecologic, compared pre- to postvaccine periods	VT prevalence decreased from 24% (1999–2005) to 5.3% (2010)
	Nationally representative survey	Markowitz, 2013 [7]	Females 14–59 years	Ecologic, compared pre- to postvaccine periods	VT prevalence decreased in 14–19 year olds from 11.5% (2003–2006) to 5.1% (2007–2010). No decrease in older age groups
Genital warts
Australia (2007)	Sexual health clinic in Melbourne	Fairley, 2009 [11]	Females and males, all ages	Ecologic, trend analysis	New GW diagnoses decreased from 12.7% (2004–2007) to 6.6% (2008) in females <28 years and from 14.3% (2004/7) to 11.8% (2008) in heterosexual males. No decrease in females ≥28 years or homosexual males
		Read, 2011 [15]	Females and males, all ages	Ecologic, trend analysis	New GW diagnoses decreased from 18.6% (2007–2008) to 1.9% (2010–2011) in females <21 years and from 22.9% (2007–2008) to 2.9% (2010–2011)in heterosexual males <21 years. No decrease in females, heterosexual males ≥30 years or homosexual males
	Sexual health clinics throughout country	Donovan, 2011 [12]	Females and males, all ages	Ecologic, trend analysis	New GW diagnoses decreased from 11–12% (2004–2007) to 4.8% (2010–2011) in female residents aged 12–26 years and from 13–14% (2004–2007) to 8.9% (2010–2011)in heterosexual males. No decrease in females >26 years or homosexual males
		Ali, 2013 [13]	Females and males, 3 age groups (<21, 21–30, >30 years)	Ecologic, compared pre- to postvaccine periods	New GW diagnoses decreased from 11.5% (2007) to .85% (2011, unvaccinated) and 0 (2011, vaccinated) in females <21 years, from 11.3% (2007) to 3.1% (2011) in females 21–30 years, and from 18.2% (2007) to 8.9% (2011) in heterosexual males
	Medicare registry	Ali, 2013 [14]	Females and males, 15–44 years, 10-year age groups	Ecologic, trend analysis	In-patientvulvar/vaginal and penile GW treatments decreased 85% (from 285 [2007] to 42 [2011]), in females 15–24 years, 24%(from 202 [2007] to 153 [2011]), infemales25–34, 71%(from51 [2007] to 15 [2011]) in males 15–24 years, and 59% (from 39 [2007] to 16 [2011]) in males 25–34 years. No decrease in males or females 35–44 years
New Zealand (2008)	Sexual health clinic in Auckland	Oliphant, 2011 [20]	Females and males, two age groups (<20, ≥20 years)	Ecologic, trend analysis	GW diagnoses decreased from 13.7% (2007) to 5.9% (2010) in females <20 years and from 11.5% (2007) to 6.9% (2010) in males <20 years. No decrease in older males or females
Denmark (2009)	National patient registry	Baandrup, 2013 [21]	Females and males, all ages	Ecologic, trend analysis	GW incidence per 100,000 person-years decreased from 381.5 (2008) to 39.8 (2011) in females 16–17 years. Smaller decrease in females 18–19, 20–21, 22–25, and 26–29. Nonsignificant decrease in males 22–25 and 26–29 years
		Blomberg, 2013 [16]	Females, birth cohorts eligible for vaccination (1989–99)	Retrospective cohort	Decrease in risk of GW among vaccinated (≥1 dose) girls compared with unvaccinated girls. Significant trend in relative risk from oldest to youngest cohort: .62, .25, .22, .12. No GW in vaccinated girls in youngest age cohort
Germany (2007)	Research database	Milolajczyk, 2013 [19]	Females and males, 10–79 years	Ecologic, trend analysis	New GW diagnoses per 100,000 person-years decreased from 316 (2005) to 242 (2008) in females 15–19 years
Sweden (2007)	National patient registry	Leval, 2012 [17]	Females, 10–44 years	Ecologic, trend analysis	GW incidence per 100,000 person-years decreased from 617 (2006) to 523 (2010) in females 15–19 years, from 1,038 (2006) to 885 (2010) in females 20–24 years, from 584 (2006) to 500 (2010) in females 25–29 years, and from 1,070 (2006) to 1,028 (2010) in males 20–24 years. Nonsignificant increase in older males and females
USA (2006)	Administrative data from family planning clinics in California	Bauer, 2012 [19]	Females and males, 4 age groups (<21, 21–25, 26–30, >30 years)	Ecologic, trend analysis	New GW diagnoses decreased from 1% (2007) to .6% (2010) in females <21 years, from 2.7% (2007) to 2.2% (2010) in males <21 years, from 1% (2007) to .9% (2010) in females 21–25 years, and from 5.1% (2006) to 4.5% (2010) in males 21–25 years. Increase in older males and females
	Private health insurance claims data throughout country	Flagg, 2013 [18]	Females and males, 10–39 years	Ecologic, trend analysis	GW prevalence decreased per 1,000 person-years from 2.9 (2006) to 1.8 (2010) in females 15–19 years and from 2009–2010 in females 20–24 years (5.5–4.8/per 1,000 person-years). No decrease in other groups
Cervical lesions
Australia (2007)	Cervical cytology registry in Victoria	Brotherton, 2009 [24]	Females, 5 age groups (<18,18–20, 21–25, 26–30, >30 years)	Ecologic, compared pre- to postvaccine periods	Decrease in high grade cervical lesions from 2007 to 2009 in females <18 years. No decrease in older age groups
USA (2006)	Population-based catchments throughout country	Powell, 2012 [23]	Females 18–31 years diagnosed with high-grade cervical lesions	Indirect cohort	Lower proportion of HPV16/18-relateda lesions in women diagnosed from 2008 to 2011 who received ≥1 vaccine dose at least 24 months before their diagnosis compared with those who were not vaccinated

GW = genital warts; VT = vaccine-type.

^aUsed consensus polymerase chain reaction and HPV typing.

^bResults are statistically significant except where noted.