Key Points
Question
Is the quadrivalent human papillomavirus (HPV) vaccine immunogenic in reproductive-aged women after hematopoietic stem cell transplant?
Findings
In this open-label nonrandomized clinical trial that included 64 women, most of the clinically stable reproductive-aged women who underwent allogeneic hematopoietic cell transplant, including those receiving immunosuppression, developed robust anti-HPV neutralizing antibody responses after vaccination similar to those observed in healthy women.
Meaning
These findings suggest that the full HPV vaccine series might be administered to reproductive-aged women after allogeneic hematopoietic stem cell transplant and that the current use of immunosuppression or prior use of rituximab after transplant does not preclude vaccination.
Abstract
Importance
Human papillomavirus (HPV) infection is found in about 40% of women who survive allogeneic hematopoietic stem cell transplant and can induce subsequent neoplasms.
Objective
To determine the safety and immunogenicity of the quadrivalent HPV vaccine (HPV-6, -11, -16, and -18) in clinically stable women post–allogeneic transplant compared with female healthy volunteers.
Interventions
Participants received the quadrivalent HPV vaccine in intramuscular injections on days 1 and 2 and then 6 months later.
Design, Setting, and Participants
This prospective, open-label phase-1 study was conducted in a government clinical research hospital and included clinically stable women posttransplant who were or were not receiving immunosuppressive therapy compared with healthy female volunteers age 18 to 50 years who were followed up or a year after first receiving quadrivalent HPV vaccination. The study was conducted from June 2, 2010, until July 19, 2016. After all of the results of the study assays were completed and available in early 2018, the analysis took place from February 2018 to May 2019.
Main Outcomes and Measures
Anti-HPV-6, -11, -16, and -18–specific antibody responses using L1 virus-like particle enzyme-linked immunosorbent assay were measured in serum before (day 1) and at months 7 and 12 postvaccination. Anti-HPV-16 and -18 neutralization titers were determined using a pseudovirion-based neutralization assay.
Results
Of 64 vaccinated women, 23 (35.9%) were receiving immunosuppressive therapy (median age, 34 years [range, 18-48 years]; median 1.2 years posttransplant), 21 (32.8%) were not receiving immunosuppression (median age, 32 years [range, 18-49 years]; median 2.5 years posttransplant), and 20 (31.3%) were healthy volunteers (median age, 32 years [range, 23-45 years]). After vaccine series completion, 18 of 23 patients receiving immunosuppression (78.3%), 20 of 21 not receiving immunosuppression (95.2%), and all 20 volunteers developed antibody responses to all quadrivalent HPV vaccine types (P = .04, comparing the 3 groups). Geometric mean antibody levels for each HPV type were higher at months 7 and 12 than at baseline in each group (all geometric mean ratios >1; P < .001) but not significantly different across groups. Antibody and neutralization titers for anti-HPV-16 and anti-HPV-18 correlated at month 7 (Spearman ρ = 0.92; P < .001 for both). Adverse events were mild and not different across groups.
Conclusions and Relevance
Treatment with the HPV vaccination was followed by strong, functionally active antibody responses against vaccine-related HPV types and no serious adverse events. These findings suggest that HPV vaccination may be safely administered to women posttransplant to potentially reduce HPV infection and related neoplasia.
Trial Registration
ClinicalTrials.gov Identifier: NCT01092195
This nonrandomized clinical trial examines the safety and immunogenicity of the quadrivalent human papillomavirus vaccine in clinically stable women post–allogeneic transplant compared with female healthy volunteers.
Introduction
Human papillomavirus (HPV) infection causes cancer of the cervix, anogenital area, and oropharynx as well as genital and cutaneous warts.1,2 Persistent infection with high-risk, oncogenic HPV types, particularly HPV-16 and -18, is an established prerequisite for the development of cervical cancer; low-risk types HPV-6 and -11 are responsible for most genital warts.1,3 In healthy individuals, infection to cancer development typically has a long latency.3,4
Allogeneic hematopoietic stem cell transplant is a form of cellular therapy that replaces the recipient’s hematopoiesis, including the humoral and cellular immune compartments. Long-term survivors of allogeneic cell transplant are at risk for infections and malignancy.5,6,7 Human papillomavirus–associated genital neoplasia, a frequent late complication after hematopoietic cell transplant in women, and HPV infection elsewhere contribute substantially to the high burden of HPV-related comorbidity and secondary malignancy in these survivors.5,6,8 The HPV disease arises in the setting of immune dysregulation, impaired cell-mediated immunity, consequences of the transplant process, and the immunosuppressive treatment of graft vs host disease.9,10 Hysterectomy does not protect women from developing HPV-related neoplasia in other anogenital or extragenital sites.6
While vaccination is encouraged following allogeneic hematopoietic cell transplant, the immunogenicity of vaccines in this immunosuppressed population is uncertain.9,10,11 Quadrivalent HPV vaccine to prevent acquisition of HPV-6, -11, -16, and -18 is safe and immunogenic in healthy reproductive-aged women conferring durable immunity.12,13,14,15 As sexual activity resumes after transplant and women remain immune-compromised, their risk of acquiring HPV is increased, especially with a new sexual partner. Reports of HPV disease developing years post–allogeneic transplant suggest a period to augment immunity through vaccination.6 We assessed the safety and immunogenicity of quadrivalent HPV vaccine in women after allogeneic hematopoietic cell transplant (including some taking immunosuppression) by measuring humoral and neutralizing HPV-specific immunity and compared them with healthy female volunteers.
Methods
Study Design
We conducted a prospective study of the immunogenicity and adverse effects of quadrivalent HPV vaccine in clinically stable, nonpregnant women and female healthy volunteers age 18 to 50 years (eAppendix in the Supplement). Healthy volunteers and participants who were at least 90 days post–allogeneic cell transplant were recruited across the Intramural Research Program at the National Institutes of Health Clinical Center from May 2010 to March 2016. We included posttransplant participants taking stable doses of immunosuppressive treatment. Women posttransplant with malignancy, life-threatening infections or uncontrolled chronic graft vs host disease, prior HPV vaccination, or HPV-related genital neoplasia requiring treatment were excluded. The study was approved by the National Institute of Child Health and Human Development institutional review board (NCT01092195). Written informed consent was provided by participants. Recording race/ethnicity was part of the National Institutes of Health policy regarding study participation and was classified by participants.
Transplant history, immunosuppressive medication use, and examination for extent of chronic graft vs host disease (including genital graft vs host disease) were recorded.16 Posttransplant immunosuppressive treatment, generally used to prevent or treat graft vs host disease, varied but typically included low doses of prednisone (<0.5 mg/kg), calcineurin inhibitors, sirolimus, or mycophenolate mofetil either alone or in combination. Healthy volunteers underwent a history and physical examination to confirm eligibility. Participants underwent gynecologic genital examination to identify HPV-related condyloma or high-grade squamous intraepithelial lesions (SILs) and obtain exfoliated cervical cells for cytology, HPV cotesting for high- and low-risk types (Hybrid Capture Test; Quest Diagnostics Nichols Institute), and a cervical mucosal sample for HPV polymerase chain reaction (PCR). Abnormal cytology results were described using the Bethesda 2001 classification system17 and clinically apparent HPV-related disease was evaluated using the American Society for Colposcopy and Cervical Pathology guidelines, including colposcopy and biopsy where indicated.18
Vaccine Dosing
The quadrivalent HPV vaccine (HPV-6, HPV-11, HPV-16, and HPV-18; Gardasil; Merck) was administered using the US Food and Drug Administration (FDA)–approved regimen of 3 separate 0.5 mL intramuscular injections at 0, 2, and 6 months. At vaccination visits, vital signs were obtained before and after vaccine administration. Participants recorded oral temperatures daily for 5 days after vaccination, injection site reactions, and systemic adverse events on a vaccination report card. Participants were contacted 2 to 3 days after vaccination to assess adverse reactions.
Follow-up
Before each vaccination and at 1 and 6 months after completing the vaccine series (study months 7 and 12), peripheral blood was obtained for complete blood cell count with differential, lymphocyte subsets and serum for research laboratories. Sexual activity was assessed19 and buccal mucosal specimens obtained for HPV type–specific testing at baseline, 7 months, and 12 months. At 12 months, a pelvic examination was conducted for cytology, HPV cotesting, and HPV type–specific testing; transplant participants underwent systemic and genital graft vs host disease assessment.16
Immunological Measurements
Anti-HPV-6, -11, -16, and -18–specific antibody levels by enzyme-linked immunosorbent assay (ELISA) were measured pre- (day 1) and postvaccination at months 2, 6, 7, and 12. Neutralization titers for HPV-16 and -18 were determined by pseudovirion-based secreted alkaline phosphatase neutralization assays 1 month after the last dose (month 7) in a single batch as previously described.20 All virus-like particles and pseudovirions used were produced at the HPV Immunology Laboratory at the Frederick National Laboratory for Cancer Research (Frederick, Maryland) as previously reported.21 Antibody levels determined by ELISA were expressed as ELISA units (EU)/mL and the seropositivity cutoffs were 8 EU/mL for anti-HPV-16 and 7 EU/mL for the others (eMethods in the Supplement). The HPV-16 and HPV-18 ELISA has been calibrated with the respective World Health Organization International Standards (HPV-16: 1 IU/mL = 5.75 EU/mL and HPV-18: 1 IU/mL = 6.81 EU/mL).
HPV DNA Measurements
DNA from each oral specimen was extracted via the MagNAPure LC DNA isolation procedure (Roche Diagnostics) as previously described.22 The extracted DNA samples were then tested for HPV DNA by PCR amplification using the HPV short PCR fragment 10 PCR DNA enzyme immunoassay LiPA25 (line probe assay) 25, version 1 (Labo Biomedical Products), which uses short PCR fragment 10 primers and LiPA25 line probe assay to provide the genotype of 26 alpha HPV types, including 12 carcinogenic (HPV-16, -18, -31, -33, -35, -39, -45, -51, -52, -56, -58, and -59) and 14 noncarcinogenic (HPV-6, -11, -34, -40, -42, -43, -44, -53, -54, -66, -68, -73, -70, and -74) types.23,24
DNA from each cervical specimen was extracted after lysis and purified by ultrafiltration. Extracted DNA samples were then tested for HPV DNA by PCR amplification using the TypeSeq HPV genotyping assay, which targets 51 HPV types, followed by next-generation sequencing25 (eMethods in the Supplement).
At baseline, participants were considered currently negative for HPV if they had normal cervical cytology results, negative pooled testing for HPV types, negative serology results for HPV-6, -11, -16, and -18 antibodies, and no history of cervical/genital treatment. Participants were classified as having HPV if they had abnormal cytology results (American Society for Colposcopy and Cervical Pathology criteria), HPV lesions on pelvic examination, or were positive on HPV pooled testing results. The HPV type–specific testing on oral and cervical specimens were ascertained as described previously.
Statistical Methods
The power and sample size were calculated based on the primary outcome of assessing the difference between anti-HPV-6, -11, -16, and -18 antibody levels at prevaccine (day 1) and postvaccination levels at month 7 (1 month after series completion) or month 12. We hypothesized that those receiving immunosuppressive treatment would have a significantly lower response than those off immunosuppression or healthy volunteers. With 20 participants in each cohort, we had more than 95% power to detect a 1.5-SD effect size between any 2 cohorts, using a 2-sided independent 2-sample z test at the significance level of .002. This adjusted α level allows for a conservative Bonferroni correction for multiple comparisons for the primary outcome. Anticipating loss to follow-up and missing samples, we planned to enroll up to 24 participants per group.
The analysis was conducted according to the study group at enrollment regardless of changes in immunosuppression for clinical indications. For baseline patient and transplant-related characteristics, the Kruskal-Wallis test and Wilcoxon rank-sum test were used to compare the continuous variables and the Fisher exact test to compare the categorical variables between study cohorts.
Because the ELISA antibody levels were not normally distributed, the geometric mean level with 95% confidence intervals was reported. The geometric mean level ratio (GMR) and 95% CIs were used to summarize the primary vaccine outcome between pre- and postvaccination. The Kruskal-Wallis test was used to compare the difference in GMR among 3 study groups and the Wilcoxon rank-sum test was used to assess the pairwise differences in GMR between study groups using a significance level of .002. As a secondary outcome, the vaccine response at months 7 and 12 was defined as any increase in antibody levels from baseline by ELISA. The Fisher exact test was used to compare the proportions of participants who developed antibody responses among the 3 study groups. Correlations between neutralizing anti-HPV-16 and -18 antibody titers and ELISA antibody levels at month 7 were assessed by the Spearman rank correlation. Baseline participant and transplant covariates, including age at vaccination, baseline HPV antibody level, time from transplant, stem cell source, donor sex and age, IgG, and cluster of differentiation (CD) 4 and CD19 levels at baseline or month 7 were examined to assess their effect on the immunogenicity of quadrivalent HPV using a multiple linear regression adjusted for the patient study group. Adverse events were analyzed by participant and vaccination. These events were categorized by the worst severity for each symptom after any vaccination. For each symptom, each participant was counted once. Individual participants could have more than one symptom.
All tests were 2-sided. For comparisons of secondary outcomes, adverse events and covariate differences among the study groups, P < .05 indicated a possible trend toward a significant association. The analysis was performed using R statistical software, version 3.6.1 (R Foundation for Statistical Computing).
Results
Participants
Sixty-five nonpregnant women were enrolled; 1 withdrew prior to vaccination (Figure 1). Twenty-three of 44 women who were postallogeneic cell transplant (52.3%) were receiving systemic immunosuppressive treatment (eTable 1 in the Supplement) and 20 (31.3%) were healthy female volunteers (Table 1). All vaccinated participants completed the vaccine series and the 7- and 12-month follow-up visit. Groups were similar for age (median, 34.3 years [receiving immunosuppressive treatment; range, 18.6-48.1], 32.2 years [not receiving immunosuppression; range, 18.3-49.9], and 32.9 years [controls; range, 23.0-45.8]; P = .40). Other baseline characteristics were comparable, except for race/ethnicity (Table 1).
Figure 1. Study Schema Diagram.
Table 1. Baseline Characteristics.
| Participant Characteristics | No. (%) | P Value | ||
|---|---|---|---|---|
| Healthy Volunteers (n = 20) | Posttransplant (n = 44) | |||
| Receiving Immunosuppression (n = 23) | Not Receiving Immunosuppression (n = 21) | |||
| Age, median (range), y | 32.9 (23.0-45.8) | 34.3 (18.3-48.1) | 32.2 (18.3-49.9) | .40 |
| Race/ethnicity | ||||
| White | 12 (60.0) | 8 (34.8) | 12 (57.1) | .01 |
| Black | 2 (10.0) | 11 (47.8) | 1 (4.8) | |
| Asian | 5 (25.0) | 1 (4.3) | 5 (23.8) | |
| Hispanic | 1 (5.0) | 3 (13.0) | 3 (14.3) | |
| Education | ||||
| High school | 0 (0) | 4 (17.4) | 6 (28.6) | .045 |
| Some college | 3 (15) | 5 (21.7) | 5 (23.8) | |
| College graduate | 5 (25) | 10 (43.5) | 5 (23.8) | |
| Graduate school | 10 (50) | 3 (13.0) | 3 (14.3) | |
| Unknown | 2 (10) | 1 (4.2) | 2 (9.5) | |
| Relationship | ||||
| Never had sex | 1 (5) | 2 (8.7) | 3 (14.3) | .80 |
| Currently sexually active | 14 (70) | 9 (39.1) | 13 (61.9) | .13 |
| Smokinga | 3 (15) | 3 (13) | 4 (19) | .91 |
| Evidence of HPV infection at baselineb | 5 (25) | 6 (26.1) | 7 (33.3) | .83 |
| HPV-negative at baselinec | 2 (10) | 9 (39.1) | 7 (33.3) | .08 |
| HPV type–specific testingd | 2 (10) | 1 (4.2) | 1 (4.8) | .68 |
| Posttransplant Patients, Transplant Characteristics | All Posttransplant (n = 44) | |||
| Age at transplant, median (range), y | 31.7 (9.7-49.2) | 32 (11.1-46.8) | 27.6 (9.7-49.2) | .17 |
| Transplant indication | ||||
| Malignant | 27 (61.4) | 14 (60.9) | 13 (61.9) | >.99 |
| Nonmalignant | 17 (38.6) | 9 (39.1) | 8 (38.1) | |
| Graft source | ||||
| Bone marrow | 7 (16.2) | 3 (13) | 4 (20) | .54 |
| Peripheral blood stem cells | 35 (81.4) | 20 (87) | 15 (75) | |
| Cord | 1 (2.3) | 0 (0) | 1 (5) | |
| HLA matching (fully matched) | 32 (72.7) | 15 (65.2) | 17 (80.9) | .32 |
| Donor relationship (related) | 30 (68.2) | 17 (73.9) | 13 (61.9) | .52 |
| Donor age, median (range), y | 33 (14-66) | 38 (14-66) | 28 (15-59) | .14 |
| Donor sex (female) | 22 (50) | 11 (47.8) | 11 (52.4) | .76 |
| Conditioning intensity (myeloablative) | 14 (31.8) | 6 (26.1) | 8 (38.1) | .52 |
| T cell depletion | 16 (36.4) | 8 (34.8) | 8 (38.1) | >.99 |
| Time since transplant, median (range), y | 2.1 (0.4-12.6) | 1.3 (0.4-7.5) | 2.3 (0.4-12.6) | .31 |
| Donor lymphocyte infusion | 8 (18.2) | 4 (17.4) | 4 (19.0) | >.99 |
| Acute GVHD | ||||
| Grade II-IV | 13 (29.5) | 8 (34.8) | 5 (23.8) | .51 |
| Grade III-IV | 4 (9.1) | 4 (17.4) | 0 (0) | .11 |
| Chronic GVHD | 21 (47.7) | 12 (52.2) | 9 (42.9) | .56 |
| Extensive | 13 (29.5) | 8 (34.8) | 5 (23.8) | .51 |
| Genital | 10 (22.7) | 6 (26.1) | 4 (19.0) | .72 |
| Rituximab use | 8 (18.1) | 4 (17.4) | 4 (19.0) | >.99 |
| IgG, median (IQR), mg/dL | 941 (674-1185) | 1020 (694-1246) | 869 (552-1057) | .44 |
| CD19, median (IQR), No. of cells/uL | 302 (105-547) | 275 (56-564) | 306 (200-501) | .58 |
| CD4, median (IQR), No. of cells/uL | 511 (269-716) | 403 (232-721) | 593 (371-709) | .34 |
Abbreviations: ASCCP, American Society for Colposcopy and Cervical Pathology; CD, cluster of differentiation; GVHD, graft vs host disease; HLA, human leukocyte antigen; HPV, human papillomavirus; IgG, immunoglobulin G; IQR, interquartile range.
SI conversion factor: To convert IgG to grams per liter, multiply by 0.01.
All smokers are former smokers.
Abnormal cytology (ASCCP criteria), HPV anogenital lesions, or HPV-positive on pooled testing for either high- or low-risk types.
HPV-negative at baseline includes negative cytology results, negative for cervical low or high-risk HPV DNA on pooled testing, and negative HPV-6/-11/-16/-18 antibodies at enrollment and no prior history of cervical or lower genital tract treatment.
HPV DNA type–specific testing for HPV-6, HPV-11, HPV-16, HPV-18 in oral or cervical specimens.
Transplant Characteristics
Baseline transplant-related characteristics were similar across cohorts (Table 1). Most underwent transplant for malignancy (27/44 [61.4%]), received peripheral blood stem cells (35/44 [79.5%]), and underwent reduced-intensity conditioning (30/44 [68.2%]). Factors identified that would potentially delay immune reconstitution included T-cell depletion (16/44 [36.4%]), development of either acute (17/44 [38.6%]) or active extensive chronic graft vs host disease (13/44 [29.5%]), or posttransplant treatment with rituximab before (8/44 [18.2%]) or during the study (2/44 [4.5%]). The vaccine was administered between 5 months to 12.5 years posttransplant (median, 1.3 years receiving and 2.3 years not receiving immunosuppressive treatment).
Baseline HPV Status
At baseline, 11 (17.2%), 9 (14.1%), 24 (37.5%), and 32 (50%) participants had detectable anti-HPV-6, -11, -16, and -18 antibodies by ELISA, respectively (eFigure 1 and eTable 2 in the Supplement). Fewer posttransplant participants not receiving immunosuppression had anti-HPV-18 antibodies (6 not receiving immunosuppression [28.6%] vs 12 receiving immunosuppression [52.2%] vs 14 health volunteers [70%]; P = .03).
More than half were currently sexually active. Eighteen of 64 (28.1%) were currently negative for HPV and 21 others (32.8%) had prior or current evidence of HPV infection (Table 1); among women undergoing colposcopy, only low-grade SIL was identified. In baseline cervical samples, 4 of 64 women (6.3%) carried either HPV-16 (n = 3) or HPV-18 (n = 1), but none carried HPV-6 or -11 (eTable 3 in the Supplement). No quadrivalent HPV vaccine types occurred in buccal samples.
Vaccine Adverse Effects
Adverse events did not differ between healthy volunteers and women posttransplant (eTable 4 in the Supplement). Some posttransplant participants (7 receiving immunosuppression [30.4%]; 5 not receiving immunosuppression [23.8%]) received other vaccines concurrently. Adverse effects were predominately limited mild injection site reactions that resolved within a few days without treatment. No detectable flares of graft vs host disease occurred after vaccination.
HPV Vaccine Response at 7 and 12 Months
After vaccine series completion, 18 of 23 patients receiving immunosuppressive treatment (78.3%), 20 of 21 (95.2%) not, and all 20 healthy volunteers developed antibody responses to all quadrivalent HPV vaccine types (P = .04 comparing across the 3 groups; eFigure 1 in the Supplement). The other 6 participants (5 posttransplant receiving immunosuppression and 1 not) had an antibody response to some but not all HPV types (eTable 1 in the Supplement).
Mean antibody levels after vaccination were significantly higher than baseline at month 7 and 12 for each HPV type and study group (all geometric mean ratios >1; P < .001; eTable 5 in the Supplement; Figure 2). At month 7 or 12, the change in HPV antibody levels from baseline was not significantly different between the 2 posttransplant groups or between either posttransplant group and healthy volunteers (Table 2; Kruskal-Wallis test; all P > .05). Neutralization assay titers for anti-HPV-16 and -18 strongly correlated with ELISA antibody levels at month 7 (Spearman ρ = 0.92; P < .001 for both; n = 61; eFigure 2 in the Supplement).
Figure 2. Human Papillomavirus (HPV)–Type-Specific Antibody Response to Quadrivalent Vaccine by Study Cohort Over Time, Measured by Enzyme-linked Immunosorbent Assay.
A, HPV-6. B, HPV-11. C, HPV-16. D, HPV-18. Geometric mean antibody levels with geometric SDs were plotted at day 1 (prevaccine baseline) and months 2, 6, 7, and 12 after the first vaccination. The blue circles represent hematopoietic stem cell transplant participants (HCT) receiving immunosuppression therapy (IST), the orange squares represent HCT not receiving IST, and the grey triangles represent healthy volunteers. Levels lower than the cutoff were given the value of 4 EU/mL.
Table 2. Geometric Mean Level Ratio at Month 7 and Month 12 vs Baseline for HPV-6, -11, -16, and -18a.
| Anti-HPV Type | GMR (95% CI)b | P Valuec | ||
|---|---|---|---|---|
| Posttransplant | Healthy Volunteers (n = 20) | |||
| Receiving Immunosuppression (n = 23) | Not Receiving Immunosuppression (n = 21) | |||
| At Month 7 Since Initial Vaccination (1 mo after dose 3) | ||||
| Anti-HPV-6 | 28.8 (8.1-102.1) | 106.6 (41.9-271.3) | 104.0 (66.1-163.8) | .17 |
| Anti-HPV-11 | 60.3 (15.9-228.5) | 172.0 (70.9-417.4) | 181.1 (121.4-270.1) | .51 |
| Anti-HPV-16 | 120.1 (32.8-439.9) | 409.8 (182.7-919.1) | 218.0 (114.4-415.3) | .26 |
| Anti-HPV-18 | 34.7 (11.4-105.7) | 108.7 (41.8-283.1) | 50.2 (29.6-85.1) | .13 |
| At Month 12 Since Initial Vaccination (6 mo after dose 3) | ||||
| Anti-HPV-6 | 9.3 (3.6-23.8) | 26.4 (12.0-58.1) | 31.0 (19.8-48.6) | .06 |
| Anti-HPV-11 | 20.6 (7.4-57.8) | 45.9 (21.7-97.1) | 46.9 (30.7-71.5) | .41 |
| Anti-HPV-16 | 39.4 (15.3-101.8) | 118.9 (62.5-226.3) | 58.3 (32.8-103.4) | .09 |
| Anti-HPV-18 | 11.5 (4.7-28.3) | 35.5 (15.4-81.6) | 12.1 (7.7-19.0) | .052 |
Abbreviations: GMR, geometric mean level ratio; HPV, human papillomavirus.
Levels lower than the cutoff were given the value of 4 EU/mL. GMR was defined as the ratio of the geometric mean levels (EU/mL) at month 7 or month 12 months vs baseline (prevaccination, day 1).
All GMRs were significantly greater than 1; P < .001.
P value using Kruskal-Wallis test to compare the 3 study groups. There were no significant differences in GMR among the study groups for anti-HPV-6, -11, -16, and -18 type at months 7 or 12 (all P > .05). Wilcoxon rank-sum tests were used to assess the pairwise differences between any 2 study groups using a significance level of .002 after Bonferroni correction and none of the pairwise comparisons showed significant difference (all P > .03, not included in Table 2).
Patient Characteristics and Immunogenicity
As observed in the general population, a lower magnitude of response was associated with increasing age among all women for anti-HPV-6 and -1126 (eFigure 3 in the Supplement). The time from transplant was not associated with the vaccine response for any anti-HPV antibody type (eFigure 4 in the Supplement). No other baseline parameters were associated with immunogenicity. In the transplant cohorts, lower CD19 T-cell subsets at month 7 were associated with a lower magnitude of response across anti-HPV antibody types (eFigure 5 in the Supplement). Among the 10 patients (22.7%) who had received rituximab posttransplant, 5 (1 receiving immunosuppression and 4 not) had an antibody response while the remaining 5 had either a poor response (3 receiving immunosuppression) or a blunted antibody response (2 receiving rituximab during the vaccination series).
Discussion
Most clinically stable reproductive-aged women who underwent allogeneic hematopoietic cell transplant, including those receiving immunosuppression, developed robust neutralizing anti-HPV antibody responses after vaccination that were not significantly different from those in healthy women. Although immune response to all 4 HPV vaccine types tended to be less likely in women posttransplant who were receiving immunosuppression than healthy women, the magnitude of response among those responding in the receiving immunosuppression and not receiving immunosuppression cohorts approached those of healthy controls after completion of the full vaccine series. Of the 6 patients with poor response to HPV vaccination (9.4%), 5 were receiving immunosuppression, including 3 who had received prior rituximab. Overall, antibody concentrations measured by ELISA were highly associated with neutralizing antibody titers as previously described.27 Adverse effects were time-limited and mild. Human papillomavirus vaccination was well tolerated after transplant and did not precipitate graft vs host disease flares, even when combined with other routine vaccinations.
Predictably, posttransplant rituximab use, which results in B cell lymphopenia, was the strongest factor associated with impaired response to the HPV vaccine as observed in other vaccine studies after rituximab.28 These findings are consistent with the observations that rituximab eliminates peripheral B cell memory in a dose-dependent manner,29 a depletion that may be prolonged.30 Importantly however, 5 of 8 participants (63%), of whom 4 were not receiving immunosuppression, developed anti-HPV responses to vaccination despite rituximab exposure at least 6 months previously; other reports suggest that such patients may develop a vaccine response.31
The HPV vaccination schedules used after allogeneic hematopoietic cell transplant were recommended by expert transplant and infectious disease committees following population-based age recommendations.9,10 Importantly, vaccination was recommended regardless of whether the recipient or donor had undergone previous HPV vaccination before the transplant. Generally, responses to vaccines comprising proteins like the quadrivalent HPV vaccine are more immunogenic than polysaccharide vaccines.32 To our knowledge, unlike other vaccinations, the lowest level of antibodies that provides protection following HPV vaccination is unknown. However, achieving antibody levels following vaccination that are greater than those observed following natural infection could be considered potentially efficacious.32 Additionally, HPV vaccines exhibit crossreactivity against nonvaccine HPV types.32 Although the HPV vaccine was shown to be highly immunogenic in the posttransplant setting, our study suggested that those who continued to receive immunosuppression or who had CD19 lymphopenia because of having received rituximab were less likely to mount antibody responses to all types in the vaccine. While these individuals might benefit from later or subsequent vaccination, studies are needed to confirm our findings and determine appropriate recommendations for these groups of patients.
As quadrivalent HPV vaccine is not a therapeutic vaccine, women warranting treatment for HPV were excluded. Study participants with low-grade SIL were followed closely to enable early treatment of worsening HPV disease. Only half of the posttransplant women were sexually active. Some showed prior immunity to HPV types or had undergone HPV treatment, yet few carried types found in the quadrivalent HPV (4 [6.3%]) or nonavalent HPV (10 [15.6%]) vaccine (Merck; eTable 3 in the Supplement). These study participants would potentially benefit from vaccination to protect them against new HPV infections. This approach follows clinical guidelines to administer HPV vaccine regardless of current HPV infection.33 The vaccine would not have a therapeutic effect against types currently causing HPV disease yet can boost immunity to other vaccine types26,34 and possibly protect against de novo exposure to new HPV infections.
Strengths and Limitations
One strength of our study was the adherence to the study schedule by participants because of multidisciplinary collaboration among investigators. Cohorts were well-matched for age and demographic characteristics; recipients were clinically stable at a median of 2.1 years after transplant. Importantly, despite heterogeneity in transplant regimens and a small sample size, the vaccine response across transplant survivors was similar in magnitude.
Our study has several limitations; the cohort was relatively small and only included women, some of whom were recruited late after transplant. Disparities in the kinetics of immune recovery within the posttransplant group may be partially due to transplant diversity.9 Posttransplant participants were allowed but not required to receive other vaccinations, making it easier to recruit participants but more difficult to attribute adverse effects exclusively to quadrivalent HPV vaccination. Human papillomavirus carriage may be underestimated by sampling only the cervix and oral cavity with the sampling techniques used. We studied only the quadrivalent HPV vaccine, which is now replaced by a nonavalent HPV vaccine that protects against acquiring HPV-6, -11, -16, and -18 and 5 additional oncogenic HPV types.21,35 Given the small sample size and transplant diversity, it is unknown whether these results are generalizable to men, all types of allogeneic transplant, or other immunosuppression regimens.
Conclusions
To our knowledge, this prospective study is the first to show the immunogenicity and functional neutralizing antibody activity induced by HPV vaccination after allogeneic hematopoietic cell transplant. Human papillomavirus vaccination increases HPV-specific immunity, protects against incident HPV infection and related neoplasia, and thus may decrease HPV disease occurrence.3,32 As recommended after transplant, the full vaccine series should be administered. Reproductive-aged men who are at risk of oropharyngeal and anogenital HPV infection may also benefit from vaccination. Importantly, the current use of immunosuppression or prior use of rituximab after transplant should not preclude vaccination. However, to maximize vaccine immunogenicity, one could consider delaying HPV vaccination until immunosuppression is discontinued and CD19 lymphopenia has resolved. Given the high HPV incidence and generally later occurrence of HPV disease after transplant, our results suggest that vaccinating women up to age 50 years, an expanded age range recently approved by the FDA for HPV vaccine use,36 combined with periodic cytology/HPV screening37 could be a practical approach to reduce incident HPV infections and subsequent HPV-associated SIL and malignant disease in this population.
eAppendix.
eMethods.
eTable 1. Immunosuppression dose, medication, contributing factors, HPV vaccine response
eTable 2. Geometric Mean Level (GMT, EU/mL) and Range for HPV-6, -11, -16, and -18 at baseline among those seropositive at baseline by ELISA.
eTable 3. Specific HPV-type by cohort
eTable 4. Adverse events
eTable 5. Geometric Mean Level (GMT, EU/mL) vs. Baseline for HPV-6, -11, -16,
and -18 at month 7 and 12.
eFigure 1. Percent seropositive by ELISA at baseline and after receiving the full quadrivalent HPV vaccine series by HPV type and study cohort.
eFigure 2. Comparison of ELISA antibody levels and PBNA neutralizing antibody
titers for HPV-16 and -18 at month 7
eFigure 3. HPV-type specific antibody response measured by ELISA to quadrivalent vaccine by age and study cohort at month 7
eFigure 4. HPV-type specific antibody response measured by ELISA to quadrivalent vaccine by time from transplant and study cohort at month 7
eFigure 5. HPV-type specific antibody response measured by ELISA to quadrivalent vaccine by CD19 T-cell value and transplant study cohort at month 7
Trial Protocol
References
- 1.Crow JM. HPV: the global burden. Nature. 2012;488(7413):S2-S3. doi: 10.1038/488S2a [DOI] [PubMed] [Google Scholar]
- 2.Forman D, de Martel C, Lacey CJ, et al. . Global burden of human papillomavirus and related diseases. Vaccine. 2012;30(suppl 5):F12-F23. doi: 10.1016/j.vaccine.2012.07.055 [DOI] [PubMed] [Google Scholar]
- 3.Lowy DR, Solomon D, Hildesheim A, Schiller JT, Schiffman M. Human papillomavirus infection and the primary and secondary prevention of cervical cancer. Cancer. 2008;113(7)(suppl):1980-1993. doi: 10.1002/cncr.23704 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Vedham V, Verma M, Mahabir S. Early-life exposures to infectious agents and later cancer development. Cancer Med. 2015;4(12):1908-1922. doi: 10.1002/cam4.538 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Wang Y, Brinch L, Jebsen P, Tanbo T, Kirschner R. A clinical study of cervical dysplasia in long-term survivors of allogeneic stem cell transplantation. Biol Blood Marrow Transplant. 2012;18(5):747-753. doi: 10.1016/j.bbmt.2011.09.012 [DOI] [PubMed] [Google Scholar]
- 6.Shanis D, Anandi P, Grant C, et al. . Risks factors and timing of genital human papillomavirus (HPV) infection in female stem cell transplant survivors: a longitudinal study. Bone Marrow Transplant. 2018;53(1):78-83. doi: 10.1038/bmt.2017.210 [DOI] [PubMed] [Google Scholar]
- 7.Chang HA, Armenian SH, Dellinger TH. Secondary neoplasms of the female lower genital tract after hematopoietic cell transplantation. J Natl Compr Canc Netw. 2018;16(2):211-218. doi: 10.6004/jnccn.2018.7005 [DOI] [PubMed] [Google Scholar]
- 8.Danylesko I, Shimoni A. Second malignancies after hematopoietic stem cell transplantation. Curr Treat Options Oncol. 2018;19(2):9. doi: 10.1007/s11864-018-0528-y [DOI] [PubMed] [Google Scholar]
- 9.Conrad A, Alcazer V, Valour F, Ader F, Lyon HSG; Lyon HEMINF Study Group . Vaccination post-allogeneic hematopoietic stem cell transplantation: what is feasible? Expert Rev Vaccines. 2018;17(4):299-309. doi: 10.1080/14760584.2018.1449649 [DOI] [PubMed] [Google Scholar]
- 10.Majhail NS, Rizzo JD, Lee SJ, et al. ; Center for International Blood and Marrow Transplant Research (CIBMTR); American Society for Blood and Marrow Transplantation (ASBMT); European Group for Blood and Marrow Transplantation (EBMT); Asia-Pacific Blood and Marrow Transplantation Group (APBMT); Bone Marrow Transplant Society of Australia and New Zealand (BMTSANZ); East Mediterranean Blood and Marrow Transplantation Group (EMBMT); Sociedade Brasileira de Transplante de Medula Ossea (SBTMO) . Recommended screening and preventive practices for long-term survivors after hematopoietic cell transplantation. Biol Blood Marrow Transplant. 2012;18(3):348-371. doi: 10.1016/j.bbmt.2011.12.519 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Gea-Banacloche J, Komanduri KV, Carpenter P, et al. . National Institutes of Health Hematopoietic Cell Transplantation Late Effects Initiative: the Immune Dysregulation and Pathobiology Working Group Report. Biol Blood Marrow Transplant. 2017;23(6):870-881. doi: 10.1016/j.bbmt.2016.10.001 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Castellsagué X, Schneider A, Kaufmann AM, Bosch FX. HPV vaccination against cervical cancer in women above 25 years of age: key considerations and current perspectives. Gynecol Oncol. 2009;115(3)(suppl):S15-S23. doi: 10.1016/j.ygyno.2009.09.021 [DOI] [PubMed] [Google Scholar]
- 13.Lehtinen M, Dillner J. Clinical trials of human papillomavirus vaccines and beyond. Nat Rev Clin Oncol. 2013;10(7):400-410. doi: 10.1038/nrclinonc.2013.84 [DOI] [PubMed] [Google Scholar]
- 14.Einstein MH, Takacs P, Chatterjee A, et al. ; HPV-010 Study Group . Comparison of long-term immunogenicity and safety of human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine and HPV-6/11/16/18 vaccine in healthy women aged 18-45 years: end-of-study analysis of a phase III randomized trial. Hum Vaccin Immunother. 2014;10(12):3435-3445. doi: 10.4161/hv.36121 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Meites E, Kempe A, Markowitz LE. Use of a 2-dose schedule for human papillomavirus vaccination—updated recommendations of the Advisory Committee on Immunization Practices. MMWR Morb Mortal Wkly Rep. 2016;65(49):1405-1408. doi: 10.15585/mmwr.mm6549a5 [DOI] [PubMed] [Google Scholar]
- 16.Filipovich AH, Weisdorf D, Pavletic S, et al. . National Institutes of Health consensus development project on criteria for clinical trials in chronic graft-versus-host disease: I. diagnosis and staging working group report. Biol Blood Marrow Transplant. 2005;11(12):945-956. doi: 10.1016/j.bbmt.2005.09.004 [DOI] [PubMed] [Google Scholar]
- 17.Solomon D, Davey D, Kurman R, et al. ; Forum Group Members; Bethesda 2001 Workshop . The 2001 Bethesda System: terminology for reporting results of cervical cytology. JAMA. 2002;287(16):2114-2119. doi: 10.1001/jama.287.16.2114 [DOI] [PubMed] [Google Scholar]
- 18.Massad LS. New guidelines on cervical cancer screening: more than just the end of annual Pap testing. J Low Genit Tract Dis. 2012;16(3):172-174. doi: 10.1097/LGT.0b013e31824bc178 [DOI] [PubMed] [Google Scholar]
- 19.Syrjala KL, Roth-Roemer SL, Abrams JR, et al. . Prevalence and predictors of sexual dysfunction in long-term survivors of marrow transplantation. J Clin Oncol. 1998;16(9):3148-3157. doi: 10.1200/JCO.1998.16.9.3148 [DOI] [PubMed] [Google Scholar]
- 20.Kemp TJ, García-Piñeres A, Falk RT, et al. ; Costa Rica Vaccine Trial (CVT) Group . Evaluation of systemic and mucosal anti-HPV16 and anti-HPV18 antibody responses from vaccinated women. Vaccine. 2008;26(29-30):3608-3616. doi: 10.1016/j.vaccine.2008.04.074 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Herrin DM, Coates EE, Costner PJ, et al. . Comparison of adaptive and innate immune responses induced by licensed vaccines for human papillomavirus. Hum Vaccin Immunother. 2014;10(12):3446-3454. doi: 10.4161/hv.34408 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Herrero R, Quint W, Hildesheim A, et al. ; CVT Vaccine Group . Reduced prevalence of oral human papillomavirus (HPV) 4 years after bivalent HPV vaccination in a randomized clinical trial in Costa Rica. PLoS One. 2013;8(7):e68329. doi: 10.1371/journal.pone.0068329 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23.Kleter B, van Doorn LJ, Schrauwen L, et al. . Development and clinical evaluation of a highly sensitive PCR-reverse hybridization line probe assay for detection and identification of anogenital human papillomavirus. J Clin Microbiol. 1999;37(8):2508-2517. doi: 10.1128/JCM.37.8.2508-2517.1999 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24.Kleter B, van Doorn LJ, ter Schegget J, et al. . Novel short-fragment PCR assay for highly sensitive broad-spectrum detection of anogenital human papillomaviruses. Am J Pathol. 1998;153(6):1731-1739. doi: 10.1016/S0002-9440(10)65688-X [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25.Wagner S, Roberson D, Boland J, et al. . Development of the TypeSeq assay for detection of 51 HPV genotypes by next generation sequencing. J Clin Microbiol. 2019;57(5):e01794. doi: 10.1128/JCM.01794-18 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26.Petersen LK, Restrepo J, Moreira ED Jr, et al. . Impact of baseline covariates on the immunogenicity of the 9-valent HPV vaccine—a combined analysis of five phase III clinical trials. Papillomavirus Res. 2017;3:105-115. doi: 10.1016/j.pvr.2017.03.002 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 27.LaMontagne DS, Mugisha E, Pan Y, et al. . Immunogenicity of bivalent HPV vaccine among partially vaccinated young adolescent girls in Uganda. Vaccine. 2014;32(47):6303-6311. doi: 10.1016/j.vaccine.2014.08.071 [DOI] [PubMed] [Google Scholar]
- 28.de Souza KJ, Ferro RS, Prestes-Carneiro LE, Carrilho PAM, Vasconcelos DM. Infectious diseases and immunological markers associated with patients with non-Hodgkin lymphoma treated with rituximab. Immunopharmacol Immunotoxicol. 2018;40(1):13-17. doi: 10.1080/08923973.2017.1392562 [DOI] [PubMed] [Google Scholar]
- 29.Cho A, Bradley B, Kauffman R, et al. . Robust memory responses against influenza vaccination in pemphigus patients previously treated with rituximab. JCI Insight. 2017;2(12):2. doi: 10.1172/jci.insight.93222 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 30.Höcker B, Aguilar M, Schnitzler P, et al. . Vaccination titres pre- and post-transplant in paediatric renal transplant recipients and the impact of immunosuppressive therapy. Pediatr Nephrol. 2018;33(5):897-910. doi: 10.1007/s00467-017-3868-0 [DOI] [PubMed] [Google Scholar]
- 31.Breedveld F, Agarwal S, Yin M, et al. . Rituximab pharmacokinetics in patients with rheumatoid arthritis: B-cell levels do not correlate with clinical response. J Clin Pharmacol. 2007;47(9):1119-1128. doi: 10.1177/0091270007305297 [DOI] [PubMed] [Google Scholar]
- 32.Schiller J, Lowy D. Explanations for the high potency of HPV prophylactic vaccines. Vaccine. 2018;36(32 Pt A):4768-4773. doi: 10.1016/j.vaccine.2017.12.079 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 33.Immunization Expert Work Group, Committee on Adolescent Health Care Committee opinion No. 704: human papillomavirus vaccination. Obstet Gynecol. 2017;129(6):e173-e178. doi: 10.1097/AOG.0000000000002052 [DOI] [PubMed] [Google Scholar]
- 34.Markowitz LE. HPV vaccines prophylactic, not therapeutic. JAMA. 2007;298(7):805-806. doi: 10.1001/jama.298.7.805 [DOI] [PubMed] [Google Scholar]
- 35.Joura EA, Giuliano AR, Iversen OE, et al. ; Broad Spectrum HPV Vaccine Study . A 9-valent HPV vaccine against infection and intraepithelial neoplasia in women. N Engl J Med. 2015;372(8):711-723. doi: 10.1056/NEJMoa1405044 [DOI] [PubMed] [Google Scholar]
- 36.US Food & Drug Administration FDA approves expanded use of Gardasil 9 to include individuals 27 through 45 years old. https://www.fda.gov/news-events/press-announcements/fda-approves-expanded-use-gardasil-9-include-individuals-27-through-45-years-old. Accessed January 3, 2019.
- 37.Bosch FX, Robles C, Díaz M, et al. . HPV-FASTER: broadening the scope for prevention of HPV-related cancer. Nat Rev Clin Oncol. 2016;13(2):119-132. doi: 10.1038/nrclinonc.2015.146 [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
eAppendix.
eMethods.
eTable 1. Immunosuppression dose, medication, contributing factors, HPV vaccine response
eTable 2. Geometric Mean Level (GMT, EU/mL) and Range for HPV-6, -11, -16, and -18 at baseline among those seropositive at baseline by ELISA.
eTable 3. Specific HPV-type by cohort
eTable 4. Adverse events
eTable 5. Geometric Mean Level (GMT, EU/mL) vs. Baseline for HPV-6, -11, -16,
and -18 at month 7 and 12.
eFigure 1. Percent seropositive by ELISA at baseline and after receiving the full quadrivalent HPV vaccine series by HPV type and study cohort.
eFigure 2. Comparison of ELISA antibody levels and PBNA neutralizing antibody
titers for HPV-16 and -18 at month 7
eFigure 3. HPV-type specific antibody response measured by ELISA to quadrivalent vaccine by age and study cohort at month 7
eFigure 4. HPV-type specific antibody response measured by ELISA to quadrivalent vaccine by time from transplant and study cohort at month 7
eFigure 5. HPV-type specific antibody response measured by ELISA to quadrivalent vaccine by CD19 T-cell value and transplant study cohort at month 7
Trial Protocol