Safety and immunogenicity of the HPV-16/18 AS04-adjuvanted vaccine in HIV-positive women in South Africa: A partially-blind randomised placebo-controlled study

In developing countries, risk of human papillomavirus (HPV) infection may be increased by the high prevalence of human immunodeficiency virus (HIV) infection. We evaluated the safety and immunogenicity of the HPV-16/18 AS04-adjuvanted vaccine in HIV-infected women in South Africa. Asymptomatic HIV-positive women aged 18–25 years (N = 120) were stratified by CD4⁺ T-cell count and randomised (1:1) to receive HPV-16/18 vaccine (Cervarix^®; GlaxoSmithKline Vaccines) or placebo (Al[OH]₃) at 0, 1 and 6 months (double-blind). HIV-negative women (N = 30) received HPV-16/18 vaccine (open label). Anti-HPV-16/18 antibody and CD4⁺ T-cell responses, CD4⁺ T-cell count, HIV viral load, HIV clinical stage and safety were evaluated for 12 months. The safety and reactogenicity profile of the HPV-16/18 vaccine was comparable in HIV-positive and HIV-negative women. Irrespective of baseline HPV status, all HIV-positive and HIV-negative women who received the HPV-16/18 vaccine were seropositive for both HPV-16 and HPV-18 after the second vaccine dose (month 2) and remained seropositive for both antigens at month 12. Anti-HPV-16/18 antibody titres at month 12 remained substantially above levels associated with natural infection. The HPV-16/18 vaccine induced sustained anti-HPV-16/18 CD4⁺ T-cell responses in both HIV-positive and HIV-negative women. No impact of baseline CD4⁺ T-cell count or HIV viral load was observed on the magnitude of the immune response in HIV-positive women. In HIV-positive women, CD4⁺ T-cell count, HIV viral load and HIV clinical stage were unaffected by HPV-16/18 vaccine administration. In conclusion, the HPV-16/18 AS04-adjuvanted vaccine appears immunogenic and well-tolerated in women with HIV infection.     

Co-administration of human papillomavirus-16/18 AS04-adjuvanted vaccine with hepatitis B vaccine: randomized study in healthy girls

Background

To evaluate co-administration of GlaxoSmithKline Biologicals’ human papillomavirus-16/18 AS04-adjuvanted vaccine (HPV) and hepatitis B vaccine (HepB).

Methods

This was a randomized, controlled, open, multicenter study. Healthy girls, aged 9-15 years, were randomized to receive HPV (n = 247), HepB (n = 247) or HPV co-administered with HepB (HPV + HepB; n = 247) at Months 0, 1 and 6. Antibodies against hepatitis B surface antigen (HBs), HPV-16 and HPV-18 were measured, and reactogenicity and safety monitored. Co-primary objectives were to demonstrate non-inferiority of hepatitis B and HPV-16/18 immune responses at Month 7 for co-administered vaccines, compared with vaccines administered alone, in the according-to-protocol cohort.

Results

The pre-defined criteria for non-inferiority were met for all co-primary immunogenicity endpoints at Month 7. Anti-HBs seroprotection rates ≥10 mIU/mL were achieved by 97.9% and 100% of girls, respectively, following co-administration or HepB alone. Anti-HBs geometric mean titers (GMTs) (95% confidence interval) were 1280.9 (973.3-1685.7) and 3107.7 (2473.1-3905.1) milli-international units/mL, respectively. Anti-HPV-16 and -18 seroconversion rates were achieved by ≥99% of girls following co-administration or HPV alone. Anti-HPV-16 GMTs were 19819.8 (16856.9-23303.6) and 21712.6 (19460.2-24225.6) ELISA units (ELU)/mL, respectively. Anti-HPV-18 GMTs were 8835.1 (7636.3-10222.1) and 8838.6 (7948.5-9828.4) ELU/mL, respectively. Co-administration was generally well tolerated.

Conclusions

The study results support the co-administration of HPV-16/18 AS04-adjuvanted vaccine with hepatitis B vaccine in adolescent girls aged 9-15 years.

Clinical trials registration

ClinicalTrials.gov registration number NCT00652938.     

Bivalent AS04-adjuvanted HPV vaccine provides optimal cancer prevention for HPV types not included in the vaccine

All available HPV vaccines contain oncogenic types 16 and 18, most often found in HPV-related cancers and precursor lesions, but they differ in their valence and adjuvant potency. The quadri- and nonavalent HPV vaccines both contain additional types 6 and 11, related to anogenital warts, while the nonavalent vaccine contains another five types that are less frequently found in cancers. The bivalent vaccine is adjuvanted by AS04. Phase-III randomised controlled trials and population-based studies on bi- and quadrivalent vaccines suggest that the two vaccines when administered to HPV-naive persons, are optimally effective in preventing cervical intra-epithelial neoplasia grade 3 or greater, caused by types 16 or 18 (specific protection). In addition, the bivalent vaccine, but not the quadrivalent vaccine, cross-protects against HPV types not contained in the vaccine. The advantage of the quadrivalent vaccine to provide additional protection against anogenital warts, should not be traded for a lower overall efficacy in preventing pre-cancerous lesions and eventually cancer.     

Impact of human papillomavirus (HPV) vaccination on HPV 16/18-related prevalence in precancerous cervical lesions

Background

Vaccination against human papillomavirus (HPV) types 16 and 18 is recommended for girls aged 11 or 12 years with catch-up vaccination through age 26 in the U.S. Cervical intraepithelial neoplasia (CIN) grade 2 or 3 and adenocarcinoma in situ (CIN2+) are used to monitor HPV vaccine impact on cervical disease. This report describes vaccination status in women diagnosed with CIN2+ and examines HPV vaccine impact on HPV 16/18-related CIN2+.

Methods

As part of a vaccine impact monitoring project (HPV-IMPACT), females 18–31 years with CIN2+ were reported from pathology laboratories in CA, CT, NY, OR, TN from 2008 to 2011. One diagnostic block was selected for HPV DNA typing with Roche Linear Array. Demographic, abnormal Papanicolaou (Pap) test dates and vaccine status information were collected. The abnormal Pap test immediately preceding the CIN2+ diagnosis was defined as the ‘trigger Pap’.

Results

Among 5083 CIN2+ cases reported to date, 3855 had vaccination history investigated; 1900 had vaccine history documented (vaccinated, with trigger Pap dates, or unvaccinated). Among women who initiated vaccination >24 months before their trigger Pap, there was a significantly lower proportion of CIN2+ lesions due to 16/18 compared to women who were not vaccinated (aPR = .67, 95% CI: .48–.94). Among the 1900 with known vaccination status, 20% initiated vaccination on/after their trigger screening. Women aged 21–23 years were more likely to initiate vaccination on/after the trigger Pap compared to 24–26 year olds (29.0% vs. 19.6%, p = .001), as were non-Hispanic blacks compared to non-Hispanic whites (27.3% vs. 19.0%, p = .001) and publicly compared to privately insured women (38.1% vs. 17.4%, p < .0001).

Conclusion

We found a significant reduction in HPV 16/18-related lesions in women with CIN2+ who initiated vaccination at least 24 months prior to their trigger Pap. These preliminary results suggest early impact of the HPV vaccine on vaccine-type disease, but further evaluation is warranted.     

Sustained efficacy and immunogenicity of the HPV-16/18 AS04-adjuvanted vaccine up to 7.3 years in young adult women

We report efficacy and immunogenicity of the HPV-16/18 AS04-adjuvanted vaccine up to 7.3 years post-vaccination. The study was conducted in a population (N = 433) of women enrolled in Brazilian centres from an initial placebo-controlled study. Women were aged 15–25 years at first vaccination. During the most recent year of follow-up, approximately 7 years after initial vaccination, no cases of infection or cytohistological lesions associated with HPV-16/18 were observed in the vaccinees. Vaccine efficacy (95% confidence interval) up to 7.3 years was 94.5% (82.9, 98.9) for incident infection, 100% (55.7, 100) for 12-month persistent infection and 100% (−129.8, 100) for cervical intraepithelial neoplasia grade 2+. Antibody titres for total IgG and neutralising antibodies remained several folds above natural infection levels and ≥96% of women were seropositive. Vaccine safety was similar to placebo. This is the longest follow-up study for a licensed cervical cancer vaccine.     

Preliminary studies on the immunogenicity of a prime-and-trap malaria vaccine in nonhuman primates

Development of next-generation vaccines against Plasmodium falciparum (Pf) is a priority. Many malaria vaccines target the pre-erythrocytic sporozoite (SPZ) and liver stages. These include subunit vaccines based on the Pf circumsporozoite protein (CSP) and attenuated PfSPZ vaccines. However, these strategies require 3–4 doses and have not achieved optimal efficacy against field-transmitted malaria. Prime-and-trap is a recently developed two-step heterologous vaccine strategy that combines priming with DNA encoding CSP followed by a single dose of attenuated SPZ. This strategy aims to induce CD8⁺ T cells that can eliminate parasites in the liver. Prior data has demonstrated that prime-and-trap with P. yoelii CSP and PySPZ was immunogenic and protective in mice. Here we report preliminary data on the immunogenicity of PfCSP prime and PfSPZ trap vaccine in rhesus macaques. This vaccine induced PfCSP-specific antibodies and T cell responses in all animals. However, response magnitude differed between individuals, suggesting further study is required.     

Efficacy and immunogenicity of a single dose of human papillomavirus vaccine compared to no vaccination or standard three and two-dose vaccination regimens: A systematic review of evidence from clinical trials

ObjectivesThis study aimed to systematically review the literature on the efficacy and immunogenicity of single-dose HPV vaccination compared to no vaccination or multi-dose schedules among vaccine trial participants.MethodsMedline, EMBASE, Global Health Database and Cochrane Central Register of Controlled Trials were searched for publications and conference abstracts (dated January 1999-August 2018) using MeSH and non-MeSH terms for human papillomavirus AND vaccines AND (immunogenicity OR efficacy/effectiveness) AND dosage. Search results were screened against pre-specified eligibility criteria. Data were extracted from included articles, and a narrative synthesis conducted on efficacy against HPV16/18 infection and humoral immunogenicity.ResultsSeven of 6,523 unique records identified were included in the review. Six were nested observational studies of participants randomised to receive two or three doses in three large HPV vaccine trials, in which some participants did not complete their allocated schedules. One small pilot study prospectively allocated participants to receive one or no vaccine dose. Frequency of HPV16/18 infection was low (e.g. <1% for 12-month-persistent infection) in all vaccinated participants up to seven years post vaccination and did not significantly differ by number of doses (p > 0.05 in all cases). Frequency of infection was significantly lower in one-dose recipients compared to unvaccinated controls (p < 0.01 for all infection endpoints in each study). HPV16/18 seropositivity rates were high in all HPV vaccine recipients (100% in three of four studies reporting this endpoint), though antibody levels were lower with one compared to two or three doses.ConclusionsThis review supports the premise that one HPV vaccine dose may be as effective in preventing HPV infection as multi-dose schedules in healthy young women. However, it also highlights the paucity of available evidence from purpose-designed, prospectively-randomised trials. Results from ongoing clinical trials assessing the efficacy and immunogenicity of single-dose HPV vaccination compared to currently-recommended schedules are awaited.     

Quadrivalent HPV vaccine in HIV-1-infected early adolescent girls and boys in Kenya: Month 7 and 12 post vaccine immunogenicity and correlation with immune status

IntroductionIn sub-Saharan Africa, a generation of HIV-1-infected children is approaching the age of sexual debut and becoming at risk for HPV infection and its sequelae. We assessed safety and immunogenicity of the quadrivalent HPV (qHPV) vaccine in HIV-1-infected adolescents.MethodsIn an open-label trial among Kenyan, HIV-1-infected adolescents aged 9–14 years, we administered the qHPV vaccine at 0, 2 and 6 months and measured antibody titers to HPV-16, 18, 6 and 11 at month 7 and 12 post-vaccination. Measures of immunogenic response from HIV-1-negative historical cohorts from Africa and HIV-1 positive adolescent cohorts from the USA were used for comparison.ResultsWe enrolled 100 girls and 80 boys with a median age of 12 years and median baseline CD4 cell count of 684 (IQR 478, 935) cells/µL. One hundred and fifty four (86%) were receiving antiretroviral therapy for a median of 4.5 (IQR 2.3, 6.3) years; 110 (71%) had <400 copies of plasma HIV-1 RNA/mL. Of 189 enrolled children, 179 received all three doses. Two hundred and eighty five (64%) of 445 adverse events were injection site reactions; none were greater than grade 2. Of 6 Serious Adverse Events (SAEs), none were considered vaccine related. Seroconversion to HPV-18, 16, 11, 6 at month 7 occurred in 93.3%, 98.3%, 97.2% and 99.6% of vaccine recipients; similar rates have been reported in historical controls. The mean log₁₀ HPV antibody titer measured at month 7 increased with each log₁₀ increase in CD4 by 1.4 (95% CI: 1.1–1.7) for HPV-18; 1.2 (0.9–1.4) for HPV-16; 1.1 (0.8–1.3) for HPV-11; 0.7 (0.5–1.0) for HPV-6 (all p < 0.0001).ConclusionAlmost all Kenyan HIV-1-infected adolescents mounted an immune response comparable to other immunized populations. HPV antibody titers were higher in those with preserved CD4 cell counts. Longer term-follow up will determine sustainability of the immune response.ClinicalTrials.gov number, NCT00557245.     

Four year immunogenicity of the RTS,S/AS02(A) malaria vaccine in Mozambican children during a phase IIb trial

Previous studies with the malaria vaccine RTS,S/AS02_A in young children in a malaria endemic area of Mozambique have shown it to have a promising safety profile and to reduce the risk of Plasmodium falciparum infection and disease.In this study, we assessed the antibody responses to the P. falciparum and hepatitis B components of the RTS,S/AS02_A vaccine over a 45 months surveillance period in a large phase IIb trial which included 2022 children aged 1-4 years at recruitment.The RTS,S/AS02_A vaccine induced high anti-circumsporozoite antibody levels with at least 96% of children remaining seropositive during the entire follow-up period. IgG titers decayed over the first 6 months of follow-up to about 25% of the initial level, but still remained 30-fold higher until month 45 compared to controls. Children with higher levels of naturally acquired immunity at baseline, assessed by blood stage indirect fluorescent antibody test, had slightly higher anti-circumsporozoite levels, after adjusting for the effect of age.The RTS,S/AS02_A vaccine also induced high levels of anti-hepatitis B surface antigen antibodies (seroprotection >97%).RTS,S/AS02_A vaccine is immunogenic and induces long-lasting anti-circumsporozoite antibodies, persisting at least 42 months after immunization. These antibodies may play a role in protection against malaria.     

Chronic helminth infection does not impair immune response to malaria transmission blocking vaccine Pfs230D1-EPA/Alhydrogel® in mice

Introduction

Malaria transmission blocking vaccines (TBV) are innovative approaches that aim to induce immunity in humans against Plasmodium during mosquito stage, neutralizing the capacity of the infected vectors to transmit malaria. Pfs230D1-EPA/Alhydrogel®, a promising protein-protein conjugate malaria TBV, is currently being tested in human clinical trials in areas where P. falciparum malaria is coendemic with helminth parasites. Helminths are complex metazoans that share the master capacity to downregulate the host immune response towards themselves and also to bystander antigens, including vaccines. However, it is not known whether the activity of a protein-based malaria TBV may be affected by a chronic helminth infection.

Case reduction and cost-effectiveness of the RTS,S/AS01 malaria vaccine alongside bed nets in Lilongwe,Malawi

BackgroundRTS,S/AS01, the most advanced vaccine against malaria, is now undergoing pilot implementation in Malawi, Ghana, and Kenya where an estimated 360,000 children will be vaccinated each year. In this study we evaluate RTS,S/AS01 alongside bed net use and estimate cost-effectiveness.MethodsRTS,S/AS01 phase III trial and bed net prevalence data were used to determine the effect of vaccination in the urban/periurban and rural areas of Lilongwe, Malawi. Cost data were used to calculate the cost-effectiveness of various interventions over three years.FindingsSince bed nets reduce malaria incidence and homogeneous vaccine efficacy was assumed, participants without bed nets received greater relative benefit from vaccination with RTS,S/AS01 than participants with bed nets. Similarly, since malaria incidence in rural Lilongwe is higher than in urban Lilongwe, the impact and cost-effectiveness of vaccine interventions is increased in rural areas. In rural Lilongwe, we estimated that vaccinating one child without a bed net would prevent 2·59 (1·62 to 3·38) cases of malaria over three years, corresponding to a cost of $10·08 (7·71 to 16·13) per case averted. Alternatively, vaccinating one child with a bed net would prevent 1·59 (0·87 to 2·57) cases, corresponding to $16·43 (10·16 to 30·06) per case averted. Providing RTS,S/AS01 to 30,000 children in rural Lilongwe was estimated to cost $782,400 and to prevent 58,611 (35,778 to 82,932) cases of malaria over a three-year period. Joint interventions providing both vaccination and bed nets (to those without them) were estimated to prevent additional cases of malaria and to be similarly cost-effective, compared to vaccine-only interventions.InterpretationTo maximize malaria prevention, vaccination and bed net distribution programs could be integrated.FundingImpacts of Environment, Host Genetics and Antigen Diversity on Malaria Vaccine Efficacy (1R01AI137410-01)     

Comparing human T cell and NK cell responses in viral-based malaria vaccine trials

Vaccination with viral-based vaccines continues to hold promise for the prevention of malaria. Whilst antigen-specific T cell responses are considered a major aim of such an approach, a role for induced NK cells as anti-malarial effector cells, or in shaping T cell responses, has received less attention. In this study naïve human volunteers were vaccinated in a prime-boost vaccination regimen comprising recombinant viral vectors fowlpox (FP9) and modified vaccinia Ankara (MVA) encoding liver-stage antigens, or a virosome vaccine. Significant T cell responses specific for the vectored vaccine antigens were demonstrated by IFNγ ELISPOT and intracellular cytokine staining (ICS) for IFNγ and IL-2, the ICS being associated with increased time to parasitaemia following subsequent challenge. Numbers of CD56^bright lymphocytes increased significantly following vaccination, as did CD3⁺ CD56⁺ lymphocytes, whilst CD56^dim cells did not. No such increases were seen with the virosome vaccine. There was no significant correlation of these CD56⁺ populations with the antigen-specific T cell responses nor time to parasitaemia. To investigate pathways of immune activation that could contribute to these lymphocyte responses, viral vectors were shown in vitro to efficiently infect APCs but not lymphocytes, and stimulated inflammatory cytokines such as type I interferons. In conclusion, measuring antigen-specific T cells is more meaningful than NK cells in these vaccination regimens.     

The study of human papillomavirus (HPV) vaccine uptake from a parental perspective: a systematic review of observational studies in the United States

Despite widespread information about the human papillomavirus (HPV) vaccine, uptake continues to be low (CDC, 2010). HPV vaccine uptake may be maximized by better understanding factors likely to influence parents' decisions to vaccinate their age-recommended children. Previous reviews have summarized barriers and facilitators likely to influence parents' decision to vaccinate their adolescents (mostly daughters) against HPV; however, less attention has been given to summarize and evaluate the methodology. The aim of this study is to systematically review the methodology used in observational studies of HPV vaccine uptake from a parental perspective. A systematic search of Academic Search Premier, CINAHL, ERIC, Medline and PsycInfo to obtain relevant articles after FDA vaccine approval (2006 to present) yielded 446 studies, of which 17 studies were eligible. Results showed the majority of studies were cross-sectional, with random sampling from list-assisted sources being the most common method for data collection. Most studies used convenience samples and relied on parental self-report. Also, the majority of studies explored vaccine initiation, but only a few explored regimen completion and timely completion of vaccine regimen. Given that the effectiveness of the HPV vaccine is based on established recommendations for a three dose regimen within a timely interval, studies on factors likely to influence regimen completion and timely completion of regimen are essential to maximize the effectiveness and public health benefits of the vaccine. Research with more diverse samples, better and increased use of random sampling techniques, and the use of precise and objective measures of vaccine uptake to supplement parental self-report, is necessary to reduce selection and information biases in future studies. Studies to inform on factors likely to influence parents' decisions to vaccinate their sons against HPV are also needed.     

Immunization of Early Adolescent Females with Human Papillomavirus Type 16 and 18 L1 Virus-Like Particle Vaccine Containing AS04 Adjuvant

PurposeIn female individuals 15–25-years of age, the AS04-containing human papillomavirus (HPV)–16/18 vaccine is highly immunogenic and provides up to 100% protection against HPV-16/18 persistent infection and associated cervical lesions up to 4.5 years. Optimal cervical cancer prevention will require prophylactic vaccination against oncogenic HPV 16 and 18 before the onset of sexual activity in early adolescent girls. To establish the feasibility of vaccination in girls 10–14 years of age, we compared the immunogenicity and safety in early adolescent female individuals to those 15–25 years in whom vaccine efficacy has been demonstrated.MethodsWe enrolled 773 female participants aged 10–14 years and 15–25 years to receive the HPV-16/18 L1 VLP AS04 vaccine, which was administered at months 0, 1, and 6. Serum samples were collected at months 0 and 7; antibodies to HPV 16 and 18 VLPs were measured by enzyme-linked immunosorbent assay. Vaccine safety was assessed at 7 or 30 days after each dose; serious adverse events were recorded during the entire study period.ResultsBoth age groups achieved 100% seroconversion for HPV 16 and 18. Participants in the group aged 10–14 years were not only noninferior to those 15–25 years in terms of HPV 16 and 18 seroconversion rates but also had approximately twice as high geometric mean titers. The vaccine was generally safe and well tolerated.ConclusionsThese findings suggest that HPV vaccination during early adolescence is generally safe, well tolerated, and highly immunogenic. The observed higher antibody titers in the group 10–14 years of age are likely to result in longer antibody persistence. Overall, these data support the implementation of prophylactic HPV vaccination in this age group.     

Reported adverse events in girls aged 13-16 years after vaccination with the human papillomavirus (HPV)-16/18 vaccine in the Netherlands

In 2009, human papillomavirus (HPV) vaccination was offered to girls born in 1993-1996 in a catch-up campaign, followed in 2010 by the implementation of the vaccination in the National Immunization Programme (NIP) for girls born in 1997. To monitor the tolerability of the 2009 catch-up campaign, we investigated the occurrence of adverse events within 7 days after vaccination with the bivalent HPV vaccine. A total of 6000 girls were asked to participate, including 1500 from each birth cohort from 1993 to 1996. One week after each of the required three successive doses, the participants received by e-mail a Web-based questionnaire focused on local reactions and systemic events. One or more questionnaires were returned by 4248 girls. Any local reaction was reported by 92.1% of the girls after the first dose, 79.4% after the second dose, and 83.3% after the third dose, and 91.7%, 78.7%, and 78.4% reported any systemic event after the three doses, respectively. Pain in the arm was the most frequently reported local reaction, of which 24.0%, 11.7%, and 14.7% was classified as pronounced. Myalgia was the most often reported systemic event. The proportion of local reactions and most systemic events was significantly lower after the second and third dose compared with the first dose (Odds ratio [OR], 0.33-0.76). Older girls reported a higher proportion of adverse events than younger girls. After vaccination with the bivalent HPV vaccine, girls 13-16 years of age reported a high proportion of short-term adverse events. These are maximum estimates and not necessarily caused by the vaccination itself. Although, girls experienced HPV vaccination as painful, no serious or unexpected adverse events were reported. The results of this survey are being communicated to health care workers and the public.     

A qualitative study of HPV vaccine acceptability among health workers, teachers, parents, female pupils, and religious leaders in northwest Tanzania

Background

As human papillomavirus (HPV) vaccines become available in developing countries, acceptability studies can help to better understand potential barriers and facilitators of HPV vaccination and guide immunisation programs.

Methods

Prior to a cluster-randomised phase IV trial of HPV vaccination delivery strategies in Mwanza Region, Tanzania, qualitative research was conducted to assess attitudes and knowledge about cervical cancer and HPV, and acceptability of and potential barriers to HPV vaccination of Tanzanian primary schoolgirls. Semi-structured interviews (n = 31) and group discussions (n = 12) were conducted with a total of 169 respondents (parents, female pupils, teachers, health workers and religious leaders).

Results

While participants had heard of cancer in general, most respondents had no knowledge of cervical cancer, HPV, or HPV vaccines. Only health workers had heard of cervical cancer but very few knew its cause or had any awareness about HPV vaccines. After participants were provided with information about cervical cancer and HPV vaccination, the majority stated that they would support HPV vaccination of their daughter to protect them against cervical cancer. Opt-out consent for vaccination was considered acceptable. Most preferred age-based vaccination, saying this would target more girls before sexual debut than class-based vaccination. Potential side effects and infertility concerns were raised by 5/14 of participating male teachers.

Discussion

Reported acceptability of HPV vaccination amongst parents, teachers and other community members was high in this population. Respondents stressed the need to provide adequate information about the vaccine to parents, that also addresses side effects and infertility concerns.     

Immune responses elicited by a fourth dose of the HPV-16/18 AS04-adjuvanted vaccine in previously vaccinated adult women

Background

Vaccines are now available for the prevention of HPV-16/18-related cervical infections and pre-cancers, primarily targeting adolescent girls. Since the risk of HPV exposure potentially persists throughout a woman's sexual life, vaccine-derived immunity should be long-term. The current study, HPV-024 (NCT00546078, http://clinicaltrials.gov), assessed the immune memory in North American women who received three doses of HPV-16/18 AS04-adjuvanted vaccine 7 years earlier in HPV-001 (NCT00689741).

Methods

Women vaccinated in HPV-001 received a 4th-dose of the HPV-16/18 vaccine (024-4DV group, N = 65). Post 4th-dose immune responses were compared with post 1st-dose immune responses in cross-vaccination controls (024-3DV group, N = 50). Reactogenicity was compared between the 4th-dose and the 1st-dose administration.

Results

Pre 4th-dose, 100% of subjects in the 024-4DV group remained seropositive for anti-HPV-16/18 antibodies (ELISA). Compared to pre 4th-dose, GMTs for anti-HPV-16 and anti-HPV-18 antibodies were respectively 9.3-fold and 8.7-fold higher at day 7, and 22.7-fold and 17.2-fold higher at month 1. Compared to post 1st-dose, GMTs for anti-HPV-16 and anti-HPV-18 were respectively 80.5-fold and 205.4-fold higher at day 7, and 11.8-fold and 20.5-fold higher at month 1. Furthermore, 68.2% and 77.3% of women had HPV-16/18 specific memory B-cells, respectively, pre 4th-dose, rising to 100% one month post 4th-dose vaccination. The 4th-dose was generally well tolerated.

Conclusion

A 4th-dose of HPV-16/18 AS04-adjuvanted vaccine triggered a rapid and strong anamnestic response in previously vaccinated women, demonstrating vaccine-induced immune memory.     

Four-year follow-up of the immunogenicity and safety of the HPV-16/18 AS04-adjuvanted vaccine when administered to adolescent girls aged 10-14 years

PurposeLong-term immunogenicity and safety of the human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine when administered to adolescent girls was evaluated.MethodsThis open-label, follow-up study (NCT00316706) was conducted in 31 centers in Taiwan, Germany, Honduras, Panama, and Colombia. In the initial study (NCT00196924), 1,035 girls aged 10–14 years received the HPV-16/18 AS04-adjuvanted vaccine at 0, 1, and 6 months. Here, geometric mean titers (GMTs) of antibodies against HPV-16, HPV-18, and monophosphoryl lipid A (MPL), a component of the AS04 Adjuvant System, were reported up to month 48.ResultsIn the according-to-protocol immunogenicity cohort (N = 563), GMTs at month 48 in initially seronegative participants were 2,374.9 (95% confidence interval: 2,205.7–2,557.0) EL.U/mL for anti-HPV-16 and 864.8 (796.9–938.4) EL.U/mL for anti-HPV-18, that is, six- and threefold higher than the plateau level in a reference study demonstrating vaccine efficacy in young women (age, 15–25 years). All participants remained seropositive for anti-HPV-16 and anti-HPV-18 at month 48. Most participants (81.8%) were seropositive for anti-MPL antibodies before vaccination. Anti-MPL antibody titers in initially seropositive participants increased initially, and then declined. Most initially seronegative participants for anti-MPL seroconverted; 69.6% remained seropositive at month 48, with anti-MPL antibody titers similar to the natural background level. The vaccine was generally well tolerated. No serious adverse events were considered related to vaccination.ConclusionsIn adolescent girls, the HPV-16/18 AS04-adjuvanted vaccine produces anti-HPV-16 and anti-HPV-18 antibody titers that are maintained for up to 4 years at higher levels than those in young women in whom vaccine efficacy against cervical lesions was demonstrated.     

HIV viral suppression results in higher antibody responses in HIV-positive women vaccinated with the quadrivalent human papillomavirus vaccine

ObjectiveTo evaluate the immunogenicity and safety of the quadrivalent HPV (qHPV) vaccine in HIV-positive women over 24 months.DesignBetween November 2008 and December 2012, 372 women aged 15 and older were enrolled from 14 Canadian HIV outpatient clinics in an open label cohort study. The qHPV vaccine (0.5 mL) was administered intramuscularly at months 0, 2 and 6. The primary study endpoint was seroconversion to any of the HPV types targeted by the qHPV vaccine. Antibody levels were measured at 0, 2, 7, 12, 18, and 24 months. Adverse events were recorded throughout.ResultsOf 372 participants enrolled, 310 (83%) received at least one dose of the qHPV vaccine and 277 (74%) received all three doses. Ninety-five percent (293/308) were seronegative for at least one vaccine type at baseline. The median age was 38 years (IQR 32–45, range 15–66), 36% were white, 44% black and 13% were of Indigenous origin. Seventy-two percent of participants had a suppressed HIV viral load (VL < 40 c/ml) at baseline, with a median CD4 count of 510 cells/mm³ (376–695). Month 7 HPV type-specific seroconversion rates were 99.0%, 98.7%, 98.1% and 93.6% for HPV types 6, 11, 16 and 18 respectively in the per-protocol population. Participants with suppressed HIV VL at first vaccine had a 1.74–3.05 fold higher peak antibody response compared to those without (p from 0.006 to <0.0001).ConclusionsThis study is the first to examine the qHPV vaccine in HIV-positive women out to 24 months and the first to include HIV-positive women through to age 66. The qHPV vaccine was well tolerated, and highly immunogenic. As women with suppressed viral load had higher antibody responses, planning HPV vaccination to occur when persons are virologically suppressed would be optimal for maximizing immune response. Findings provide strong evidence that older HIV-positive women can still benefit from HPV vaccination.Clinical trial registration: http://www.isrctn.com/ISRCTN33674451     

Comparing immunogenicity of the Escherichia coli-produced bivalent human papillomavirus vaccine in females of different ages

BackgroundThe safety and efficacy of a recently licensed Escherichia coli (E. coli)-produced bivalent HPV vaccine have been shown. Specific antibody levels are important indicators to evaluate the efficacy of vaccination. Therefore, we compared the immunogenicity of this HPV 16/18 vaccine in females of different ages in this study.MethodsImmunogenicity of the vaccine was analyzed in the per-protocol sets for immunogenicity (PPS-I) of a phase III trial and an immune-bridging trial. The serum samples were collected at month 0 and one month after the final dose (month 7) to assess the specific IgG antibody levels by ELISA. The seroconversion rates, geometric mean concentration (GMC), and geometric mean increase (GMI) were used to assess the immunogenicity of the test vaccine. The non-linear association of antibody levels with age was estimated via natural cubic splines and the Akaike information criterion was used to assess optimal model.ResultsBy combining the PPS-I data from the two trials, nearly all of the females seroconverted for both HPV types. In the 3-dose group, the GMC of IgG to both HPV types decreased with increasing age, especially in adolescent girls and young women. For HPV-16 and -18, the declining trend slowed down in women older than 32 and 35 years old, respectively. The GMI ranged from 648 to 80 for HPV-16 and from 218 to 42 for HPV-18. In the 2-dose group, the specific antibodies for HPV-16 and -18 peaked in girls aged 10 years with GMIs of 401 and 98, respectively, and then decreased with age.ConclusionsThe E. coli-produced bivalent HPV-16/18 vaccine induced specific antibody responses in females aged 9–45 years. The antibody levels were inversely associated with age, and the declining trends slowed down in women older than 32 or 35 years for HPV-16 and -18, respectively.