• cervical cancer;
  • human papillomavirus;
  • HPV-16/18 adjuvanted vaccine;
  • long-term immune response;
  • cervicovaginal secretion


  1. Top of page
  2. Abstract
  3. Material and Methods
  4. Results
  5. Discussion
  6. Acknowledgements
  7. References

Vaccination against oncogenic human papillomavirus (HPV) types is one key intervention for cervical cancer prevention. This follow-up study assessed the persistence of the systemic and mucosal immune responses together with the safety profile of the HPV-16/18 AS04-adjuvanted vaccine administered to young women aged 10–25 years. Serum and cervicovaginal secretion (CVS) samples were collected at prespecified time-points during the 48-month follow-up period. Anti-HPV-16/18 antibody levels in serum and CVS were measured by enzyme-linked immunosorbent assay (ELISA). At Month 48, all subjects remained seropositive for serum anti-HPV-16 and -18 antibodies. As previously observed, anti-HPV-16 and -18 antibodies levels (ELISA Units/mL) were higher in subjects vaccinated at the age of 10–14 years (2862.2 and 940.8) compared to subjects vaccinated at the age of 15–25 years (1186.2 and 469.8). Moreover, anti-HPV-16 and -18 antibodies in CVS were still detectable for subjects aged 15–25 years (84.1% and 69.7%, respectively). There was a strong correlation between serum and CVS anti-HPV-16 and -18 antibodies levels (correlation coefficients = 0.84 and 0.90 at Month 48, respectively) supporting the hypothesis of transudation or exudation of serum immunoglobulin G antibodies through the cervical epithelium. The HPV-16/18 AS04-adjuvanted vaccine had a clinically acceptable safety profile. In conclusion, this follow-up study shows that the HPV-16/18 AS04-adjuvanted vaccine administered to preteen/adolescents girls and young women induces long-term systemic and mucosal immune response and has a clinically acceptable safety profile up to 4 years after the first vaccine dose.

Cervical cancer is the second most common cancer among women worldwide, with nearly 500,000 new cases and approximately 270,000 deaths each year.1, 2 Human papillomavirus (HPV) infection with oncogenic types is well recognized as the necessary cause of virtually all cervical cancers, and HPV DNA has been found in 99.7% of all cases.2–4 HPV types 16 and 18 are the most common oncogenic HPV types, responsible for about 70% of all cervical cancers.5, 6

In their lifetime, up to 80% of women will acquire an HPV infection.7, 8 The majority of these natural infections resolve within two years,8, 9 but the induced antibody levels are low and many women do not seroconvert at all.10, 11 Moreover, the prevalence and the persistence of infection with oncogenic HPV types appear to be higher compared to nononcogenic HPV types.7, 9, 12 Immunity conferred by natural infection may not reliably protect against (re)-infection, hence, vaccination against oncogenic HPV types is important for the overall strategy of cervical cancer prevention.

To this end, GlaxoSmithKline (GSK) Biologicals has developed a L1 protein virus-like-particle (VLP) vaccine (Cervarix®) against oncogenic types HPV-16 and HPV-18 formulated with the AS04 adjuvant system.13 In previous trials, the HPV-16/18 AS04-adjuvanted vaccine (HPV-16/18 vaccine) was shown to have a clinically acceptable safety profile,14 to be immunogenic15, 16 and to prevent incident and persistent HPV-16/18 infection and associated cervical neoplasia.16–20 In addition, the HPV-16/18 vaccine has shown cross-protection against some nonvaccine oncogenic HPV types, including HPV -31, -33, and -45.16, 17, 19, 21 Long-term efficacy and immunogenicity, along with a clinically acceptable safety profile, were demonstrated up to 7.3 years after vaccination of women aged 15–25 years with this vaccine.18, 19, 22 In women aged 15–55 years, the HPV-16/18 vaccine induced a robust immune response, in serum and cervicovaginal secretions (CVS), which has been shown to persist for at least 24 months.23

The mechanism by which the HPV-16/18 vaccine induces protection is not completely understood. The HPV-16/18 vaccine prevents HPV infection of basal cells in the cervical epithelium, likely through the induction of high and sustained titers of neutralizing immunoglobulin G (IgG) antibodies. The level of serum antibodies induced by HPV-vaccination is 10–100 times higher than that following natural infection.16, 18, 19, 24, 25 Most vaccine-induced genital tract antibodies are reported to derive from the circulation by transudation or exudation across the cervical epithelium to the cervical mucus, where they bind to the HPV's outer shell (capsid) and prevent infection of host cells.26–28 These antibodies may, however, also be actively transported or locally produced in the cervical mucosa by a mucosal immunization.29

Vaccination against oncogenic HPV types before sexual debut is important since 50% of HPV infections in women are acquired during the first three years of their sexually active lives30, 31 and the incidence of HPV infections remains high up to ten years after sexual debut.7, 32, 33 Moreover, the highest rates of HPV infections have consistently been found in women younger than 25 years of age. The duration of vaccine-induced protection is therefore critical as women are at risk of infection with an oncogenic HPV type throughout their sexually active life.8, 34, 35

The initial phase of our study (Pedersen et al.,15 Month 7) provided evidence that the HPV-16/18 vaccine elicited higher anti-HPV-16/18 antibody levels in preteen/adolescent girls (aged 10–14 years) as compared to young adult women (aged 15–25 years) and had a clinically acceptable safety profile.

Here, we present extended follow-up data from that study where the persistence of the serum and mucosal immune response and the safety profile of the HPV-16/18 vaccine have been evaluated up to 4 years after vaccination of preteen/adolescent girls and young adult women.

Material and Methods

  1. Top of page
  2. Abstract
  3. Material and Methods
  4. Results
  5. Discussion
  6. Acknowledgements
  7. References

Study objectives

The primary objective of this follow-up study was to evaluate the long-term immunogenicity of the HPV-16/18 vaccine in young women (vaccinated at the age of 10–25 years with three vaccine doses) who completed a visit 48 months after the first vaccine injection (Month 48).

The secondary objectives were: (i) to compare the immune responses to the HPV-16/18 vaccine in sera from subjects enrolled in our study with responses measured in sera from adults of previous studies in which efficacy has been shown;16, 19, 22 (ii) to evaluate anti-HPV-16 and -18 antibodies responses in CVS samples and to compare the antibody levels in CVS with antibody levels in sera from subjects vaccinated pre- and postmenarche; and (iii) to evaluate the safety of the HPV-16/18 vaccine during long-term follow-up.

Study design

The primary study took place from September 2004 to July 2005 in 17 centers in Denmark, Estonia, Finland, Greece, The Netherlands, and Russia (Fig. 1).

thumbnail image

Figure 1. Primary and extended follow-up study design: Vaccine administration, serologic and cervicovaginal secretion evaluation. M: Month.

Download figure to PowerPoint

The primary study included healthy female subjects divided in two age groups: the 10–14 years age group (subjects aged 10–14 years at the time of first vaccine injection) and the 15–25 years age group (subjects aged 15–25 years at the time of first vaccine injection). Participants of the 15–25 years age group were randomized (1:1:1) to receive one of three consecutive production lots of the industrial scale HPV-16/18 vaccine. A randomization blocking scheme was used to ensure that treatments were assigned equally and randomly. All participants of the 10–14 years age group received vaccine from the same production lot. Another group of women aged 15–25 years received an HPV-16/18 vaccine prepared using a modified manufacturing process and were not included in the publication.15

The extension study was conducted in Denmark, Estonia and Finland from June 2006 to January 2009 as a phase III, open, multicentric, follow-up study (NCT00337818) designed to evaluate the safety and immunogenicity of the HPV-16/18 vaccine up to Month 48 in subjects vaccinated at the age of 10–25 years (Fig. 1).

Study population and ethics

Participants were enrolled in the primary study if: (i) they were abstinent from sexual activity, or were using adequate contraceptive precautions for 30 days before vaccination and up to 2 months after completion of the vaccination series; (ii) they had negative pregnancy test results (if they were of childbearing potential); and (iii) they had no more than six lifetime sexual partners. Individuals were excluded from the extension study at the time of study entry if they had used an investigational product, a nonregistered product or chronic immune-modifying drugs. Exclusion criteria included also the administration of immunoglobulins or blood products within 3 months prior to a blood sampling.

To be eligible for the extension study, the subjects had to have participated in the primary study in Denmark, Estonia or Finland, to have received three doses of the HPV-16/18 vaccine (at Months 0, 1 and 6) and to have completed the Month 7 visit.15 Subjects who missed assessment at Month 18 (i.e., first visit of the extension study) were eligible to join the study at Month 24.

All participants had to sign the written informed consent before enrollment. For subjects below the legal age of consent, written informed consent had to be obtained from a parent or legally acceptable representative and, in addition, the subject had to sign and personally date a written informed assent.

The study protocol, any amendments, the informed consent and other information that required preapproval were reviewed and approved by a national, regional, or investigational centre Ethics Review Committee or Institutional Review Board.

Our study was conducted in accordance with good clinical practice (GCP) and all applicable regulatory requirements, including, where applicable, the Declaration of Helsinki. All distributed material had received prior approval by the Ethics Review Committees.

Study vaccines

The HPV-16/18 vaccine (GSK Biologicals, Rixensart, Belgium) contains HPV-16 and -18 L1 proteins self-assembled as VLP and is formulated with AS04, an adjuvant system known to enhance the vaccine's immunogenicity.36 Each dose of the HPV-16/18 vaccine contains 20 μg of each HPV-16 and -18 L1 proteins adjuvanted with 550 μg of AS04 (500 μg aluminium hydroxide and 50 μg 3-O-desacyl-4′-monophosphoryl lipid A). The HPV-16/18 vaccine was supplied in individual 0.5-mL prefilled syringes and administered into the deltoid muscle on a 0-, 1- and 6-month schedule (Fig. 1).15

Serologic and CVS evaluations

In the follow-up study, blood samples were collected at Months 18, 24, 36 and 48 for measurement of anti-HPV-16 and -18 antibody titers in serum (Fig. 1). All blood samples were evaluated for anti-HPV-16 and -18 antibodies using type-specific enzyme-linked immunosorbent assay (ELISA) at GSK Biologicals Laboratories, Rixensart, Belgium.

Anti-HPV-16 and -18 antibodies were also measured in CVS samples collected at Months 24, 36 and 48 in postmenarcheal subjects who volunteered for the procedure (Fig. 1). CVS samples were collected using ophthalmic sponges (Merocel® Eye Spear or Sponge Points [Medtronic Inc; Jacksonville, Florida, USA]). The sponge was placed in contact with the cervix for 30–60 seconds to absorb mucus. Antibody extraction from CVS samples was performed at GSK Biologicals Laboratories, Rixensart, Belgium and anti-HPV-16 and -18 IgG antibodies were detected and quantified according to ELISA serum standardized protocols as previously published.16, 23, 37

To avoid any bias in results, the presence of blood in CVS samples was evaluated using the Hemastix® (Bayer Healthcare LLC) reagent strip test. After extraction of antibodies from CVS by two washing steps, a fixed volume of extracted sample was dispensed onto the strip test end. After one minute, the color of the test pad was matched to the color chart on the bottle label. Results were expressed as 0, 10, 25, 80, or 200 erythrocytes per μL.

Vaccine safety

The occurrence of serious adverse events (SAEs), medically significant adverse events (AEs), new onset of chronic diseases (NOCDs) and pregnancies was recorded throughout the entire study period. AEs, withdrawal due to AE(s), pregnancies and their outcomes were described in detail. SAEs were further evaluated for their clinical relevance and relationship to vaccination.

SAEs were defined as any untoward medical occurrence that was life-threatening, required hospitalization, resulted in disability or incapacity, was an important medical event, resulted in death, or was a congenital anomaly/birth defect in the offspring of a study participant. Medically significant AEs were defined as adverse events prompting emergency room or physician visits, which were not related to common diseases or routine visits for physical examination or vaccination or SAEs not related to common diseases. NOCDs included autoimmune conditions, allergies and asthma.

Statistical methods

The primary immunogenicity analysis was performed on the according-to-protocol (ATP) immunogenicity cohort which included all evaluable subjects, i.e., subjects who were included in the primary study ATP immunogenicity analyses, meeting all eligibility criteria, complying with the procedures and intervals defined in the protocol with no elimination criteria during the study and for whom serology results were available for a particular blood sampling time point (at Month 18, 24, 36 or 48) of the extension phase. A supplementary analysis was performed on the Total Vaccinated cohort (TVC) which included all vaccinated subjects who received three doses of HPV-16/18 vaccine in the primary study and for whom data were available.

Seropositivity rates (with 95% confidence interval [CI]) were calculated for anti-HPV-16 and -18 in both groups. Seropositivity was defined as a titer greater than or equal to the assay threshold established at 8 ELISA Units/mL (EL.U/mL) for anti-HPV-16 and 7 EL.U/mL for anti-HPV-18.15, 19 The range and distribution of antibody concentrations in serum were tabulated by geometric mean titers (GMTs) and their 95% CI for anti-HPV-16 and -18 at each time-point.

In the absence of an accepted serological correlate of protection, descriptive comparisons were performed between anti-HPV-16 and -18 GMTs in our study and anti-HPV-16 and -18 GMTs in women aged 15–25 years who cleared a natural infection and mounted an immune response in the Phase III PATRICIA trial.16 The immunogenicity results were also compared to the anti-HPV-16 and -18 GMTs from the plateau phase of the HPV-007 efficacy study at Months 45–50.19, 22

For the subjects who volunteered to provide CVS samples, correlation between serum and CVS antibody concentrations was calculated by Pearson coefficient. To minimize the antibody titer variation during the menstrual cycle, antibody titers (expressed in EL.U/mL) measured in CVS and in serum were divided by the amount of total IgG measured in μg/mL.28 This ratio (expressed in EL.U/μg) was used for the correlation. CVS samples with Hemastix® value >200 erythrocytes per μL were excluded from analyses.

Safety analyses were performed on the TVC. The percentages of subjects reporting at least one SAE, NOCD or other medically significant AE throughout the study (between Month 0 and Month 48) were tabulated with their exact 95% CI per treatment group.

The analyses were performed using Statistical Analysis System 9.1 and Proc StatXact 7.0.


  1. Top of page
  2. Abstract
  3. Material and Methods
  4. Results
  5. Discussion
  6. Acknowledgements
  7. References

Study population

Of the 616 subjects who received at least one dose of HPV-16/18 vaccine prepared using standard manufacturing process in the primary study, 321 were from the three countries that accepted to participate in the extension study. Of these, 243 subjects entered the extension study, 220 subjects (51 aged 10–14 years and 169 aged 15–25 years at the first vaccination) attended the visit at Month 48 and 193 subjects (50 from the 10–14 years age group and 143 from the 15–25 years age group) were included in the ATP cohort for immunogenicity (Fig. 2).

thumbnail image

Figure 2. Flow of participants through the primary and extension study and definition of analyses cohorts. *Greece, Russia and The Netherlands declined participation in the extension study. TVC: total vaccinated cohort; ATP: according-to-protocol; N: number of subjects; M7: Month 7; M48: Month 48; S+: seropositive.

Download figure to PowerPoint

At Month 48, the mean ages of participants (TVC cohort) were 15.7 years for the group of subjects aged 10–14 years at the time of first vaccine injection and 24.2 years for the group of subjects aged 15–25 years at the same time. Almost all subjects were White/Caucasian (98.2%). When compared to the demographic characteristics of the primary study, subjects in the two age groups participating in the extension study were of similar age and heritage (data not shown).


Most subjects of the 10–14 and 15–25 years age groups were seronegative for anti-HPV-16 antibodies (100% and 87.2%, respectively) and for anti-HPV-18 antibodies (95.8% and 87.2%, respectively) prior to vaccination. All initially seronegative subjects had seroconverted after vaccination and remained seropositive for both antibodies up to 4 years after the first vaccine dose (Table 1).

Table 1. Seropositivity rates and GMTs for serum HPV-16/18 IgG antibodies by pre-vaccination status (ATP immunogenicity cohort Month 48)
inline image

Immunological kinetic profiles showed that anti-HPV-16/18 antibodies peaked at Month 7, then gradually declined in all age groups tending towards a plateau (Fig. 3). At Month 48, GMTs (EL.U/mL) (95% CI) for anti-HPV-16 in initially seronegative subjects were 2862.2 (2129.3–3847.3) in the 10–14 years age group and 1186.2 (1007.4–1396.8) in the 15–25 years age group (Fig. 3a). Anti-HPV-18 antibody GMTs were respectively 940.8 (714.8–1238.3) and 469.8 (394.7–559.2) for the same age groups and time-point (Fig. 3b). At all time-points postvaccination, GMTs were higher in subjects of the 10–14 years age group compared to subjects of the 15–25 years age group for anti-HPV-16 antibodies (between 2.4- and 2.9-fold) and anti-HPV-18 antibodies (between 2.0- and 2.5-fold).

thumbnail image

Figure 3. Geometric mean titers of anti-HPV-16 (a) and -18 (b) antibodies in initially seronegative subjects aged 10–14 years and 15–25 years at the time of first vaccination (ATP immunogenicity cohort Month 48). 10–14 years: subjects aged 10–14 years at the time of first vaccine dose; 15–25 years: subjects aged 15–25 years at the time of first vaccine dose; GMT: geometric mean titer; Error bars: 95% CI: 95% confidence interval; Seropositivity rates shown above bars. Results of Month 18 were not presented since only eight subjects attended the visit. Natural infection: GMTs of subjects from Study HPV-008 who were HPV-16 (a) or -18 (b) DNA negative and seropositive at baseline (i.e., who had cleared a natural infection; GMT: 29.8 EL.U/mL (a) or GMT: 22.7 EL.U/mL (b))16

Plateau phase: GMTs of subjects from Study HPV-007 in women aged 15–25 years at Months 45–50 after the first vaccine dose (Total cohort; GMT: 397.8 EL.U/mL (a) or GMT: 297.3 EL.U/mL (b))19, 22

Download figure to PowerPoint

In initially seronegative subjects of the 10–14 and 15–25 years age groups, anti-HPV-16 antibody GMTs at Month 48 were, respectively, 96.0- and 39.8-fold higher than anti-HPV-16 antibody levels achieved in subjects who cleared a natural infection and mounted an immune response in the Phase III PATRICIA trial (Fig. 3a).16 Anti-HPV-18 antibody GMTs were respectively 41.4- and 20.7-fold higher than levels after a natural infection for the same age groups (Fig. 3b). Compared to the plateau level observed in subjects from another study in which sustained efficacy of the HPV-16/18 vaccine has been demonstrated,19, 22 anti-HPV-16 antibody titers were respectively 7.2- and 3.0-fold higher in the 10–14 years and the 15–25 years age groups (Fig. 3a). Anti-HPV-18 antibody titers were ∼3.2- and 1.6-fold higher than the plateau level for the same age groups (Fig. 3b).

At Month 48, anti-HPV-16 and -18 antibody testing in CVS was performed on 69 and 66 samples (with Hemastix® < 200 erythrocytes/μL) from subjects of the 15–25 years age group. Anti-HPV-16 and -18 antibodies were detected in CVS from 84.1% (95% CI: 73.3, 91.8) and 69.7% (95% CI: 57.1, 80.4) of subjects. Similar data were observed in CVS samples tested at Month 24 and Month 36.

Serum anti-HPV-16 and -18 IgG antibody response was evaluated at different time-points in subjects with and without detectable anti-HPV-16/18 IgG antibodies in their CVS at Month 48 (Table 2). All subjects remained seropositive for anti-HPV-16 and -18 antibodies at Month 48. However, subjects with detectable cervicovaginal anti-HPV-16 IgG antibodies displayed higher anti-HPV-16 serum GMTs than subjects without detectable antibodies in CVS. The difference in anti-HPV-16 GMTs between subjects with and without detectable cervicovaginal antibodies increased with time (from 1.7 fold at Month 7 to 3.2 fold at Month 48). A comparable trend was observed for anti-HPV-18 IgG antibodies.

Table 2. Comparison of serum antibody response in HPV-16/18 vaccinated young women with and without detectable cervicovaginal anti-HPV-16/18 IgG antibodies at Month 48 (TVC, 15–25 years age group)
inline image

A strong and direct correlation was observed between antibody levels in serum and CVS from the subjects of the 15–25 years age group throughout the study. The correlation coefficients (R) between antibody levels in serum and CVS for anti-HPV-16 antibodies were 0.93, 0.91 and 0.84 at Month 24, 36 and 48, respectively. For anti-HPV-18 antibodies the correlation coefficients were 0.93, 0.91 and 0.90 for the same time-points (Fig. 4).

thumbnail image

Figure 4. Correlation between antibody levels in serum and CVS samples at Month 24, Month 36 and Month 48 for anti-HPV-16 (a) and -18 (b) antibodies. The scatter plots show the ratio (specific IgG/total IgG) transformed to linear log10 values (TVC, 15–25 years age group). M24: Month 24; M36: Month 36; M48: Month 48; R: correlation coefficient.

Download figure to PowerPoint


Throughout the study (Month 0 to Month 48), a total of 27 SAEs were reported by 23 subjects. Four subjects (2.5% CI: 0.7, 6.4) reported 4 SAEs in the 10–14 years age group and 19 subjects (4.1% CI: 2.5, 6.4) reported 23 SAEs in the 15–25 years age group. None of these events was considered to be possibly related to the study vaccination by the investigator.

Twenty-two subjects (13.9% CI: 8.9, 20.3) reported 24 medically significant AEs in the 10–14 years age group and 92 subjects (20.1% CI: 16.5, 24.1) reported 144 medically significant AEs in the 15–25 years age group. The most frequently reported medically significant AEs were depression (11), cystitis (9), asthma (6) and acne (5).

Three subjects (1.9% CI: 0.4, 5.4) in the 10–14 years age group and 19 subjects (4.1% CI: 2.5, 6.4) in the 15–25 years age group reported respectively 3 and 20 NOCDs (based on GSK assessment). The most frequently reported NOCDs were asthma (5) and hypothyroidism (3). None of these events were considered as possibly related to study vaccination by the investigator.

Of 45 pregnancies reported (one in the 10–14 years age group and 44 in the 15–25 years age group), there were 35 normal births, one stillbirth, one therapeutic abortion and one missed abortion in the same subject, four elective terminations and three premature infants.


  1. Top of page
  2. Abstract
  3. Material and Methods
  4. Results
  5. Discussion
  6. Acknowledgements
  7. References

This long-term follow-up study was designed to evaluate the immunogenicity and safety of the HPV-16/18 vaccine in healthy female subjects (aged 10 to 25 years at the first vaccine injection) up to four years after administration of the first vaccine dose. The vaccine had a clinically acceptable safety profile and high serum and mucosal anti-HPV-16 and -18 antibody levels were observed up to Month 48.

All initially seronegative subjects seroconverted and remained seropositive for both anti-HPV-16 and -18 antibodies throughout the study, regardless of their age at vaccination. The immunological kinetic profiles, showing peak titers gradually declining and tending towards a plateau in all age groups, were similar to those observed in other HPV-16/18 vaccine clinical efficacy trials.16, 19, 23 In line with previous studies, anti-HPV-16 and -18 serum antibody titers at Month 48 were still substantially higher than titers elicited by a natural infection,16 and they were above antibody levels associated with sustained protection observed in previous clinical trials.19, 22 This high and sustained immune response induced by the vaccine may in part be explained by the presence of the AS04 adjuvant system in the vaccine formulation.36

Results from the primary study showed that the vaccine induced higher antibody titers when administered to young adolescents aged 10–14 years as compared to young women aged 15–25 years.15 The results of Month 7 were not unexpected since immune response to vaccination is known to be enhanced in younger populations compared to advancing age groups.38–40 Of importance, the same trend was observed throughout the four years of follow-up in the extension study, which therefore brings new findings of major significance with regards to the expected long-lasting protection.

Preclinical studies have demonstrated the role of species-specific antibodies, directed against HPV L1 capsid protein, in protection against HPV infection and subsequent lesion development41 in three distinct animal model systems (canine oral papillomavirus,42 cottontail rabbit papillomavirus43–45 and bovine papillomavirus46). One possible mechanism of protection at the mucosal surface is the transudation/exudation of serum IgG antibodies into CVS. In humans, high levels of mucosal antibodies could prevent virus particles from infecting the cervical basal cell layer at the transformation zone, which is the metaplastic zone between the squamous and columnar epithelium in the cervix where cervical cancers usually develop.47 Serum IgG antibodies are thought to transudate or exudate at this site across the cervical epithelium.27, 48 In a previous study, systemic immunization with HPV-16 VLPs has been shown to elicit high titers of anti-HPV-16-specific IgG antibodies in cervical secretions, which were believed to be derived from serum transudation.28 Similarly, the presence of anti-HPV antibodies at the cervix in women following administration of the HPV-16/18 vaccine has also been reported.23, 26, 49 Moreover, a previous study showed that CVS antibody positivity rates for both anti-HPV-16 and -18 were higher after administration of the HPV-16/18 vaccine than after administration of a quadrivalent VLP HPV-6/11/16/18 vaccine.50

In our study, mucosal immune response to the HPV-16/18 vaccine was evaluated in CVS samples provided by subjects on a voluntary basis. The correlation between CVS and serum titration for antibodies against HPV-16 and HPV-18 was assessed and analysed. At Month 48, 84.1% and 69.7% of subjects vaccinated at the age of 15 to 25 years still had detectable antibody titers in their CVS samples for respectively anti-HPV-16 and anti-HPV-18. The strong correlation between serum and CVS antibodies persisted until Month 48, suggesting that transudation/exudation of serum IgG antibodies to the cervical epithelium is long-standing. Results of three other studies confirm that women who had detectable anti-HPV-16/18 antibodies in CVS reported consistently higher antibody levels in serum, regardless of age.23, 49, 50

The immune response was further evaluated regarding the presence or absence of detectable cervicovaginal anti-HPV-16 and -18 IgG antibodies 48 months after the first vaccine injection. Throughout the study, subjects with detectable CVS antibodies had higher serum GMTs for anti-HPV-16/18 IgG antibodies than subjects with no detectable cervicovaginal anti-HPV-16/18 antibodies. This suggests that the antibody transudation from serum to CVS depends on the antibody level in the serum. Indeed, even if serum antibody levels decreased with time in both groups, the drop-off was slightly higher in subjects without detectable CVS antibodies at Month 48. On the other hand, in the group without detectable CVS antibodies, lower GMTs were observed from the beginning for anti-HPV-18 and from Month 24 onwards for anti-HPV-16. In the absence of an accepted serological correlate of protection, it is unclear whether this group may respond differently to the vaccine and might turn susceptible to infections caused by different HPV types at different times in the future.

The safety analysis revealed a clinically acceptable profile. The frequency of SAEs, medically significant AEs and NOCDs were comparable to those reported in previous analyses.15

The main limitations of our study were the number of subjects in the 48-month follow-up study which was lower compared to the primary study, the limited number of subjects from whom CVS samples were assessable and the fact that CVS samples were not collected since the beginning of the study. The proportion and the demographic characteristics of subjects in the initially 10–14 years and 15–25 years age groups were, however, conserved in the follow-up study.

In conclusion, the long-term immunogenicity in serum and CVS of the HPV-16/18 vaccine for both HPV-16 and HPV-18 was demonstrated. The vaccine had a clinically acceptable safety profile when administered to healthy female subjects aged 10 to 25 years. Moreover, the previously observed higher anti-HPV-16/18 antibody levels in early adolescents as compared to young adults persisted up to 4 years after the first vaccine dose. The strong correlation between levels of anti-HPV-16/18 antibodies in serum and CVS up to Month 48 supports long-term transudation or exudation of serum IgG antibodies to the cervical epithelium. These data support the administration of HPV-16/18 vaccine in preteen/adolescent girls and in young women.


  1. Top of page
  2. Abstract
  3. Material and Methods
  4. Results
  5. Discussion
  6. Acknowledgements
  7. References

The authors acknowledge and thank the study participants and all clinical study site personnel who contributed to the conduct of this trial: Nete Bulow, Lene Hergens, Trine Bager, Britt Kaa, Inge Jensen, Annette Lorenz, Tiina Eriksson, Suvi Siikala, Mari Saarela and Ulla Beldjerd.

The authors also acknowledge the GlaxoSmithKline Biologicals Clinical Study network: Mercedes Lojo Suarez for providing global study coordination; Dominique Eggerickx for the clinical study coordination; Olivier Godeaux for the clinical development; Sylviane Poncelet for the clinical immunology; Katherine Ward for the scientific writing protocol preparation.

We thank Claire Verbelen, Mélanie Muylaert and Denis Sohy for providing editorial assistance and article coordination on behalf of GlaxoSmithKline Biologicals.

Cervarix® is a registered trademark of the GlaxoSmithKline group of companies. Merocel® Eye Spear is a registered trademark of Medtronic Inc. Hemastix® is a registered trademark of Bayer Healthcare LLC.


  1. Top of page
  2. Abstract
  3. Material and Methods
  4. Results
  5. Discussion
  6. Acknowledgements
  7. References
  • 1
    Sankaranarayanan R, Ferlay J. Worldwide burden of gynaecological cancer: the size of the problem. Best Pract Res Clin Obstet Gynaecol 2006; 20: 20725.
  • 2
    Schiffman M, Castle PE, Jeronimo J, Rodriguez AC, Wacholder S. Human papillomavirus and cervical cancer. Lancet 2007; 370: 890907.
  • 3
    Walboomers JM, Jacobs MV, Manos MM, Bosch FX, Kummer JA, Shah KV, Snijders PJ, Peto J, Meijer CJ, Muñoz N. Human papillomavirus is a necessary cause of invasive cervical cancer worldwide. J Pathol 1999; 189: 129.
  • 4
    Bosch FX, Lorincz A, Muñoz N, Meijer CJ, Shah KV. The causal relation between human papillomavirus and cervical cancer. J Clin Pathol 2002; 55: 24465.
  • 5
    Muñoz N, Bosch FX, Castellsagué X, Diaz M, de Sanjosé S, Hammouda D, Shah KV, Meijer CJ. Against which human papillomavirus types shall we vaccinate and screen? The international perspective. Int J Cancer 2004; 111: 27885.
  • 6
    Bosch FX, Burchell AN, Schiffman M, Giuliano AR, de Sanjose S, Bruni L, Tortolero-Luna G, Kjaer SK, Muñoz N. Epidemiology and natural history of human papillomavirus infections and type-specific implications in cervical neoplasia. Vaccine 2008; 26: K116.
  • 7
    Baseman J, Koutsky L. The epidemiology of human papillomavirus infections. J Clin Virol 2005; 32S: S1624.
  • 8
    Dunne EF, Unger ER, Sternberg M, McQuillan G, Swan DC, Patel SS, Markowitz LE. Prevalence of HPV infection among females in the United States. JAMA 2007; 297: 8139.
  • 9
    Richardson H, Kelsall G, Tellier P, Voyer H, Abrahamowicz M, Ferenczy A, Coutlée F, Franco EL. The natural history of type-specific human papillomavirus infections in female university students. Cancer Epidemiol Biomarkers Prev 2003; 12: 48590.
  • 10
    Dillner J. The serological response to papillomaviruses. Semin Cancer Biol 1999; 9: 42330.
  • 11
    Ho G, Studentsov Y, Bierman R, Burk R. Natural history of human papillomavirus type 16 virus-like-particle antibodies in young women. Cancer Epidemiol Biomarkers Prev 2004; 13: 1106.
  • 12
    Franco EL, Villa LL, Sobrinho JP, Prado JM, Rousseau MC, Désy M, Rohan TE. Epidemiology of acquisition and clearance of cervical human papillomavirus infection in women from a high-risk area for cervical cancer. J Infect Dis 1999; 180: 141523.
  • 13
    Garçon N, Chomez P, Van Mechelen M. GlaxoSmithKline Adjuvant Systems in vaccines: concepts, achievements and perspectives. Expert Rev Vaccines 2007; 6: 72339.
  • 14
    Descamps D, Hardt K, Spiessens B, Izurieta P, Verstraeten T, Breuer T, Dubin G. Safety of human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine for cervical cancer prevention: a pooled analysis of 11 clinical trials. Hum Vaccin 2009; 5: 33240.
  • 15
    Pedersen C, Petaja T, Strauss G, Rumke HC, Poder A, Richardus JH, Spiessens B, Descamps D, Hardt K, Lehtinen M, Dubin G. Immunization of early adolescent females with human papillomavirus type 16 and 18 L1 virus-like particle vaccine containing AS04 adjuvant. J Adolesc Health 2007; 40: 56471.
  • 16
    Paavonen J, Jenkins D, Bosch FX, Naud P, Salmerón J, Wheeler CM, Chow S- N, Apter DL, Kitchener HC, Castellsague X, de Carvalho NS, Skinner SR et al. Efficacy of a prophylactic adjuvanted bivalent L1 virus-like-particle vaccine against infection with human papillomavirus types 16 and 18 in young women: an interim analysis of a phase III double-blind, randomised controlled trial. Lancet 2007; 369: 216170.
  • 17
    Paavonen J, Naud P, Salmerón J, Wheeler CM, Chow SN, Apter D, Kitchener H, Castellsague X, Teixeira JC, Skinner SR, Hedrick J, Jaisamrarn U et al. Efficacy of human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine against cervical infection and precancer caused by oncogenic HPV types (PATRICIA): final analysis of a double-blind, randomised study in young women. Lancet 2009; 374: 30114.
  • 18
    De Carvalho N, Teixeira J, Roteli-Martins CM, Naud P, De Borba P, Zahaf T, Sanchez N, Schuind A. Sustained efficacy and immunogenicity of the HPV-16/18 AS04-adjuvanted vaccine up to 7.3 years in young adult women. Vaccine 2010; 28: 624755.
  • 19
    Harper DM, Franco EL, Wheeler CM, Moscicki AB, Romanowski B, Roteli-Martins CM, Jenkins D, Schuind A, Costa Clemens SA, Dubin G. Sustained efficacy up to 4.5 years of a bivalent L1 virus-like particle vaccine against human papillomavirus types 16 and 18: follow-up from a randomised control trial. Lancet 2006; 367: 124755.
  • 20
    Harper DM. Impact of vaccination with Cervarix™ on subsequent HPV-16/18 infection and cervical disease in women 15–25 years of age. Gynecol Oncol 2008; 110: S117.
  • 21
    Jenkins D. A review of cross-protection against oncogenic HPV by an HPV-16/18 AS04-adjuvanted cervical cancer vaccine: importance of virological and clinical endpoints and implications for mass vaccination in cervical cancer prevention. Gynecol Oncol 2008; 110: S1825.
  • 22
    The GlaxoSmithKline Vaccine HPV-007 Study Group. Sustained efficacy and immunogenicity of the HPV-16/18 AS04-adjuvanted vaccine: analysis of a randomised placebo-controlled trial up to 6.4 years. Lancet 2009; 374: 197585.
  • 23
    Schwarz TF, Spaczynski M, Schneider A, Wysocki J, Galaj A, Perona P, Poncelet S, Zahaf T, Hardt K, Descamps D, Dubin G. Immunogenicity and tolerability of an HPV-16/18 AS04-adjuvanted prophylactic cervical cancer vaccine in women aged 15–55 years. Vaccine 2009; 22: 5817.
  • 24
    Villa LL, Costa RL, Petta CA, Andrade RP, Ault KA, Giuliano AR, Wheeler CM, Koutsky LA, Malm C, Lehtinen M, Skjeldestad FE, Olsson SE et al. Prophylactic quadrivalent human papillomavirus (types 6, 11, 16, and 18) L1 virus-like particle vaccine in young women: a randomised double-blind placebo-controlled multicentre phase II efficacy trial. Lancet Oncol 2005; 6: 2718.
  • 25
    Villa LL. Overview of the clinical development and results of a quadrivalent HPV (types 6, 11, 16, 18) vaccine. Int J Infect Dis 2007; 11: S1725.
  • 26
    Kemp TJ, García-Piñere A, Falk RT, Poncelet S, Dessy F, Giannini SL, Rodriguez AC, Porras C, Herrero R, Hildesheim A, Pinto LA. Evaluation of systemic and mucosal anti-HPV16 and anti-HPV18 antibody responses from vaccinated women. Vaccine 2008; 26: 360816.
  • 27
    Schwarz TF, Leo O. Immune response to human papillomavirus after prophylactic vaccination with AS04-adjuvanted HPV-16/18 vaccine: improving upon nature. Gynecol Oncol 2008; 110: S110.
  • 28
    Nardelli-Haeffliger D, Wirthner D, Schiller JT, Lowy DR, Hildesheim A, Ponci F, De Grandi P. Specific antibody levels at the cervix during the menstrual cycle of women vaccinated with human papillomavirus 16 virus-like particles. J Natl Cancer Inst 2003; 95: 112837.
  • 29
    Nardelli-Haefliger D, Lurati F, Wirthner D, Spertini F, Schiller JT, Lowy DR, Ponci F, DeGrandi P. Immune response induced by lower airway mucosal immunisation with a human papillomavirus type 16 virus-like particle vaccine Vaccine 2005; 23: 363441.
  • 30
    Collins S, Mazloomzadeh S, Winter H, Blomfield P, Bailey A, Young LS, Woodman CBJ. High incidence of cervical human papillomavirus infection in women during their first sexual relationship. Br J Obstet Gynaecol 2002; 109: 968.
  • 31
    Winer RL, Lee SK, Hughes JP, Adam DE, Kiviat NB, Koutsky LA. Genital human papillomavirus infection: incidence and risk factors in a cohort of female university students. Am J Epidemiol 2003; 157: 21826.
  • 32
    Rozendaal L, Walboomers JM, van der Linden JC, Voorhorst FJ, Kenemans P, Helmerhorst TJ, van Ballegooijen M, Meijer CJ. PCR-based high-risk HPV test in cervical cancer screening gives objective risk assessment of women with cytomorphologically normal cervical smears. Int J Cancer 1996; 68: 7669.
  • 33
    Laukkanen P, Koskela P, Pukkala E, Dillner J, Läärä E, Knekt P, Lehtinen M. Time trends in incidence and prevalence of human papillomavirus type 6, 11 and 16 infections in Finland. J Gen Virol 2003; 84: 21059.
  • 34
    Coupé VMH, Berkhof J, Bulkmans NWJ, Snijders PJF, Meijer CJLM. Age-dependent prevalence of 14 high-risk HPV types in the Netherlands: implications for prophylactic vaccination and screening. Br J Cancer 2008; 98: 64651.
  • 35
    Castellsagué X, Schneider A, Kaufman AM, Bosch FX. HPV vaccination against cervical cancer in women above 25 years of age: key considerations and current perspectives. Gynecol Oncol 2009; 115: S15S23.
  • 36
    Giannini SL, Hanon E, Moris P, Van Mechelen M, Morel S, Dessy F, Fourneau MA, Colau B, Suzich J, Losonksy G, Martin MT, Dubin G et al. Enhanced humoral and memory B cell immunity using HPV16/18 L1 VLP vaccine formulated with the MPL/aluminium salt combination (AS04) compared to aluminium salt only. Vaccine 2006; 24: 593749.
  • 37
    Castle PE, Rodriguez AC, Bowman FP, Herrero R, Schiffman M, Bratti MC, Morera LA, Schust D, Crowley-Nowick P, Hildesheim A. Comparison of ophthalmic sponges for measurements of immune markers from cervical secretions. Clin Diagn Lab Immunol 2004; 11: 399405.
  • 38
    Fisman DN, Agrawal D, Leder K. The effect of age on immunologic response to recombinant hepatitis B vaccine: a meta-analysis. Clin Infect Dis 2002; 35: 136875.
  • 39
    Kumar R, Burns EA. Age-related decline in immunity: implications for vaccine responsiveness. Expert Rev Vaccines 2008; 7: 46779.
  • 40
    Sambhara S, McElhaney JE. Immunosenescence and influenza vaccine efficacy. Curr Top Microbiol Immunol 2009; 333: 41329.
  • 41
    Christensen N, Reed C, Cladel N, Han R, Kreider J. Immunization with viruslike particles induces long-term protection of rabbits against challenge with cottontail rabbit papillomavirus. J Virol 1996; 70: 9605.
  • 42
    Suzich JA, Ghim SJ, Palmer-Hill FJ, White WI, Tamura JK, Bell JA, Newsome, JA, Jenson AB, Schlegel R. Systemic immunization with papillomavirus L1 protein completely prevents the development of viral mucosal papillomas. Proc Natl Acad Sci USA 1995; 92: 115537.
  • 43
    Lin Y-L, Borenstein LA, Selvakumar R, Ahmed R, Wettstein FO. Effective vaccination against papilloma development by immunization with Ll or L2 structural protein of cottontail rabbit papillomavirus. Virology 1992; 187: 6129.
  • 44
    Jansen KU, Rosolowsky M, Schultz LD, Markus HZ, Cook JC, Donnelly JJ., Martinez D, Ellis RW, Shaw AR. Vaccination with yeast-expressed cottontail rabbit papillomavirus (CRPV) virus-like particles protects rabbits from CRPV-induced papilloma formation. Vaccine 1995; 13: 150914.
  • 45
    Breitburd F, Ramoz N, Salmon J, Orth G. HLA control in the progression of human papillomavirus infections. Semin Cancer Biol 1997; 7: 35971.
  • 46
    Kirnbauer R. Papillomavirus-like particles for serology and vaccine development. Intervirology 1996; 39: 5461.
  • 47
    Roden R, Monie A, Wu TC. The impact of preventive HPV vaccination. Discov Med 2006; 6: 17581.
  • 48
    Stanley M, Lowy DR, Frazer I. Prophylactic HPV vaccines: Underlying mechanisms. Vaccine 2006; 24: S10613.
  • 49
    GlaxoSmithKline Clinical Trials Register. Complementary testing to further evaluate the immunogenicity of GSK Biologicals' HPV vaccine (580299) in healthy female subjects aged over 26 years enrolled in study 104820. Available at: (accessed February 11, 2010).
  • 50
    Einstein MH, Baron M, Levin M, Chatterjee A, Edwards RP, Zepp F, Carletti I, Dessy FJ, Trofa AF, Schuind A, Dubin G. Comparison of the immunogenicity and safety of Cervarix™ and Gardasil® human papillomavirus (HPV) cervical cancer vaccines in healthy women aged 18–45 years. Hum Vaccin 2009; 5: 70519.