Cytomegalovirus DNAemia Requiring (Val)Ganciclovir Treatment for More Than 8 Weeks Is a Key Factor in the Development of Antiviral Drug Resistance.

Background: Prolonged (val)ganciclovir [(V)GCV] exposure for ≥6 weeks is a known predisposing factor for cytomegalovirus (CMV) drug resistance. However, the selection of this threshold was based on limited data. In this study, we sought to reappraise the risk factors for the development of (V)GCV resistance through a specific focus on kidney transplant recipients (KTRs). Methods: This single-center retrospective study included 313 consecutive KTRs treated for a first CMV episode. Adjusted Cox multivariate regression analysis was used for identifying independent risk factors. Results: Antiviral drug resistance was identified in 20 (6%) KTRs. A cumulative (V)GCV exposure for more than 6 weeks (regardless of the viral load) was not associated with antiviral drug resistance (hazard ratio [HR] = 2.45, 95% confidence interval [CI] = 0.33-18.30, P = .38). In contrast, persistent CMV DNAemia requiring (V)GCV treatment for more than 8 weeks was the main independent risk factor for antiviral drug resistance (HR = 11.68, 95% CI = 2.62-52.01, P = .001). The (V)GCV treatment for more than 8 weeks was given to 9% and 18% of patients who had persistent or recurrent CMV DNAemia, respectively. These scenarios were associated with the occurrence of drug resistance in 39% and 12% of cases, respectively. Conclusions: Cumulative (V)GCV exposure ≥6 weeks regardless of the viral load is not associated with antiviral drug resistance. In contrast, prolonged exposure to (V)GCV during CMV replication (with a cutoff ³8 weeks) seems to be a key factor.

Impact of new cyclooxygenase 2 inhibitors on human cytomegalovirus replication in vitro.

BACKGROUND: Human cytomegalovirus (HCMV) is involved in complications on immunocompromised patients. Current therapeutics are associated with several drawbacks, such as nephrotoxicity. PURPOSE: As HCMV infection affects inflammation pathways, especially prostaglandin E2 (PGE2) production via cyclooxygenase 2 enzyme (COX-2), we designed 2'-hydroxychalcone compounds to inhibit human cytomegalovirus. STUDY DESIGN: We first selected the most efficient new synthetic chalcones for their effect against COX-2-catalyzed PGE2. STUDY SAMPLE: Among the selected compounds, we assessed the antiviral efficacy against different HCMV strains, such as the laboratory strain AD169 and clinical strains (naïve or multi-resistant to conventional drugs) and toxicity on human cells. RESULTS: The most efficient and less toxic compound (chalcone 7) was tested against HCMV in combination with other antiviral molecules: artesunate (ART), baicalein (BAI), maribavir (MBV), ganciclovir (GCV), and quercetin (QUER) using Compusyn software. Association of chalcone 7 with MBV and BAI is synergistic, antagonistic with QUER, and additive with GCV and ART. CONCLUSION: These results provide a promising search path for potential bitherapies against HCMV.

Letermovir breakthroughs during the French Named Patient Programme: interest of monitoring blood concentration in clinical practice.

OBJECTIVES: To analyse mechanisms of letermovir breakthrough during compassionate primary and secondary prophylaxis. METHODS: Mechanisms of letermovir breakthrough during compassionate primary and secondary prophylaxis were analysed in four patients from the French Named Patient Programme by the French National Reference Centre for Herpesviruses. RESULTS: Of three absolute resistance cases, two were associated with treatment interruption or low letermovir concentrations in blood. A fourth case of breakthrough was not associated with resistance. Next-generation sequencing (NGS) genotyping confirmed rapid emergence of resistant mutants, within 3 months of treatment initiation. CONCLUSIONS: Measurement of letermovir concentration and genotyping should be recommended for patient follow-up during letermovir therapy.

The human cytomegalovirus terminase complex as an antiviral target: a close-up view.

Human cytomegalovirus (HCMV) is responsible for life-threatening infections in immunocompromised individuals and can cause serious congenital malformations. Available antivirals target the viral polymerase but are subject to cross-resistance and toxicity. New antivirals targeting other replication steps and inducing fewer adverse effects are therefore needed. During HCMV replication, DNA maturation and packaging are performed by the terminase complex, which cleaves DNA to package the genome into the capsid. Identified in herpesviruses and bacteriophages, and with no counterpart in mammalian cells, these terminase proteins are ideal targets for highly specific antivirals. A new terminase inhibitor, letermovir, recently proved effective against HCMV in phase III clinical trials, but the mechanism of action is unclear. Letermovir has no significant activity against other herpesvirus or non-human CMV. This review focuses on the highly conserved mechanism of HCMV DNA-packaging and the potential of the terminase complex to serve as an antiviral target. We describe the intrinsic mechanism of DNA-packaging, highlighting the structure-function relationship of HCMV terminase complex components.

Identification of a short sequence in the HCMV terminase pUL56 essential for interaction with pUL89 subunit.

The human cytomegalovirus (HCMV) terminase complex consists of several components acting together to cleave viral DNA into unit length genomes and translocate them into capsids, a critical process in the production of infectious virions subsequent to DNA replication. Previous studies suggest that the carboxyl-terminal portion of the pUL56 subunit interacts with the pUL89 subunit. However, the specific interacting residues of pUL56 remain unknown. We identified a conserved sequence in the C-terminal moiety of pUL56 (671WMVVKYMGFF680). Overrepresentation of conserved aromatic amino acids through 20 herpesviruses homologues of pUL56 suggests an involvement of this short peptide into the interaction between the larger pUL56 terminase subunit and the smaller pUL89 subunit. Use of Alpha technology highlighted an interaction between pUL56 and pUL89 driven through the peptide 671WMVVKYMGFF680. A deletion of these residues blocks viral replication. We hypothesize that it is the consequence of the disruption of the pUL56-pUL89 interaction. These results show that this motif is essential for HCMV replication and could be a target for development of new small antiviral drugs or peptidomimetics.

Contrasting effect of new HCMV pUL54 mutations on antiviral drug susceptibility: Benefits and limits of 3D analysis.

Human cytomegalovirus (HCMV) resistance to antiviral drugs is a major drawback of repeated or long-duration treatment in immunocompromised patients. Resistance testing is usually performed by genotypic assays. For accurate interpretation of these assays, the role of new mutations in HCMV resistance has to be assessed. Two previously unknown UL54 single point mutations (D515Y and V787A) were characterized for phenotypic drug-resistance by marker transfer analysis using bacterial artificial chromosome (BAC) mutagenesis. Increases in 50% inhibitory concentrations of ganciclovir and foscarnet were found for both mutated recombinant strains showing that mutations D515Y and V787A induce resistance to both antivirals. Importantly, none of those impacted the viral growth kinetics. For a better understanding of their molecular resistance mechanisms, a 3D homology model was used to localize the mutated amino-acids in functional domains of UL54 and predict their impact on UL54 function and resistance. However, 3D homology model analysis has limits and phenotypic characterization using BAC-HCMV is still essential to measure the role of unknown mutations.

Ex vivo model of congenital cytomegalovirus infection and new combination therapies.

INTRODUCTION: Congenital human cytomegalovirus (HCMV) infection is a major public health problem due to severe sequelae in the fetus and newborns. Currently, due to their toxicity anti-CMV treatments cannot be administered to pregnant women. We thus developed an ex vivo model of 1(st) trimester placental CMV infection to observe the route of infection across the placenta and to test the efficacy of various new drugs targeting different stages of viral cycle. METHODS: After validation of the viability of floating villi explants by ELISA ß-HCG, the kinetics of placental infection were determined by immunochemistry and qPCR in this ex vivo model. Antiviral susceptibility was determined in vitro using focus reduction assay and by qPCR in the ex vivo model. RESULTS: The ex vivo model showed viral infection in trophoblasts and mesenchymal space of floating villi. In vitro, antiviral combinations of maribavir with baïcalein or artesunate inhibited viral infection by more than 90%. On the other hand, in ex vivo model, infection was reduced by 40% in presence of maribavir and artesunate. The synergistic effect observed in vitro was not observed ex vivo. DISCUSSION: This model allowed us to understand the CMV spread in 1(st) trimester floating villi better and to analyze the anti-CMV efficacy and toxicity of new drugs that could be administered to pregnant women, either alone or in combination. CONCLUSIONS: Such an ex vivo model could be applied to other viruses such as rubella or parvovirus B19 and in new drug development.

Human cytomegalovirus quantification in toddlers saliva from day care centers and emergency unit: a feasibility study.

BACKGROUND: Cytomegalovirus (CMV) infection is the most important cause of congenital viral infection in developed countries. In utero transmission occurs at higher rates in seronegative women during primary infection, especially those in contact with young children in day-care centers (DCC). Nevertheless data on variability of CMV excretion among children in French DCCs are lacking, and are important for public health planning. OBJECTIVES: Our main objective was to assess the feasibility of a salivary sample in DCCs in order to study CMV excretion among toddlers. Our secondary aims were to assess prevalence of CMV excretion in children attending Hospital Emergency Unit (EU) in comparison with various types of DCCs and to validate the analytical chain for collected specimens. STUDY DESIGN: Excretion of CMV in saliva was quantified using a real-time PCR assay in children aged from 3 months to 6 years old in EU and in DCC, with gB, gH and gN genotypes determined in infected children. Salivary sampling was performed using small sponges placed into a DNA conservation medium. Socio cultural and medical information were collected from attending parents. RESULTS: A total of 625 children were included, with 256 from six DCCs and 369 from one EU. In DCCs, the acceptability of the procedure was 87.3% (95%CI 78.5-96.2) amongst parents and children, and in the EU, acceptability was higher at 97.6% (95%CI 95.5-98.9). CMV shedding overall prevalence was 21.7% (95%CI 17.6-26.2), with CMV shedding prevalence in DCCs of 51.9% (95%CI 22.8-81.1). CONCLUSION: We validated the feasibility and acceptability of measuring CMV shedding in the saliva of French toddlers. The discrepancy between CMV infection rates in day care centers and in the general population (as sampled in the EU) indicates the need for a further study to determine risk factors and shedding levels in the DCC population.

Interest of human papillomavirus DNA quantification and genotyping in paired cervical and urine samples to detect cervical lesions.

BACKGROUND: Cervical cancer is caused by persistent infection with high-risk human papillomavirus (HR-HPV). Conventional human papillomavirus (HPV) testing requires cervical sampling. However, vaginal and urine self-sampling methods are more acceptable for patients and result in increased participation when they are available in screening programs. In this context, we have developed a non-invasive screening method via the detection of HPV DNA in urine samples. PURPOSE: To compare HPV viral loads and genotypes in paired cervical and urine samples, and to assess correlation between virological and cytological results in women seeking gynecological consultation. METHODS: Paired urine and cervical specimens were collected and analyzed from 230 of 245 women participating in the previously described prospective PapU study. HPV DNA detection and quantification were performed using a real-time PCR method with short fragment PCR primers. Genotyping was carried out using the INNO-LiPA HPV genotyping assay. RESULTS: The prevalence of HPV in the 230 paired urine and cervical smear samples was 42 and 49 %, respectively. Overall agreement for HPV positivity and negativity between the paired samples was 90 % (κ = 0.80). High HPV viral load in both cervical and urine samples was associated with cytological abnormalities. HPV-positive women were mostly infected with HR-HPV types. The agreement between high- and low-risk HPV (LR-HPV) detection in both samples was 97 % (κ = 0.95 for HR-HPV and κ = 0.97 for LR-HPV). CONCLUSIONS: High concordance rates for HPV-DNA quantification and high/low-risk HPV genotyping in paired urine/cervical samples suggest that urinary HPV DNA testing could be useful for cervical lesion screening.

Maribavir use in practice for cytomegalovirus infection in French transplantation centers.

Maribavir (MBV), a UL97 inhibitor, shows good oral bioavailability, low host cell toxicity, and theoretical benefits to inhibit cross-resistant viruses. We herein examined clinical and virological outcomes of 12 patients, including 3 bone marrow recipients and 9 organ recipients infected with resistant cytomegalovirus (CMV) and treated with MBV during 2011-2012. All received at least 800-mg daily doses. They had developed clinical (12/12) and/or virological (11/12) resistance to CMV infection. Based on a decrease of viral load in blood >1.5 log copies/mL half of them responded to MBV treatment. The individual changes varied from a rapid decrease in viral load (n = 4) to no response (n = 3) with some late response slowly decreasing viremia (n = 3). In 2 cases MBV was used as secondary prophylaxis. No clear parameter emerged as a clinical surrogate for nonresponse to MBV. These results contrast with the lack of efficacy in phase III trials of MBV prophylaxis among stem cell recipients, which were possibly due to low doses or inadequate timing of drug initiation in the study. Additional clinical and surrogate laboratory markers are needed to determine antiviral responses to guide MBV use. Dosage ranging studies might benefit future MBV use.

[Gardasil®-induced erythema nodosum]. / Erythème noueux induit par le Gardasil®.

Erythema nodosum is a panniculitis occurring more frequently in young women. We report a 16-year-old woman who presented with erythema nodosum that occurred following Gardasil® administration (vaccine against HPV types 6, 11, 16 and 18) and that is proposed to young female. This adverse effect is not a contraindication to the HPV vaccination because its benefit against the oncogene risk of Papillomavirus is documented.

Insight into the structure of the pUL89 C-terminal domain of the human cytomegalovirus terminase complex.

In a previous study, we identified 12 conserved domains within pUL89, the small terminase subunit of the human cytomegalovirus. A latter study showed that the fragment pUL89(580-600) plays an important role in the formation of the terminase complex by interacting with the large terminase subunit pUL56. In this study, analysis was performed to solve the structure of pUL89(568-635) in 50% H2O/50% acetonitrile (v/v). We showed that pUL89(568-635) consists of four alpha helices, but we did not identify any tertiary structure. The fragment 580-600 formed an amphipathic alpha helix, which had a hydrophobic side highly conserved among herpesviral homologs of pUL89; this was not observed for its hydrophilic side. The modeling of pUL89(457-612) using the recognition fold method allowed us to position pUL89(580-600) within this domain. The theoretical structure highlighted three important features. First, we identified a metal-binding pocket containing residues Asp(463), Glu(534), and Glu(588), which are highly conserved among pUL89 homologs. Second, the model predicted a positively charged surface able to interact with the DNA duplex during the nicking event. Third, a hydrophobic patch on the top of the catalytic site suggested that this may constitute part of the pUL89 site recognized by pUL56 potentially involved in DNA binding.

[HPV detection and typing by INNO-LiPA assay on liquid cytology media Easyfix Labonord after extraction QIAamp DNA Blood Mini Kit Qiagen and Nuclisens easyMAG Biomérieux]. / Dépistage et typage des infections à HPV par technique INNO-LiPA sur milieu liquide Easyfix Labonord après extraction QIAamp DNA Blood Mini Kit Qiagen et Nuclisens easyMAG Biomérieux.

OBJECTIVES: The objective of this study is to validate the use of test INNO-LIPA HPV Genotyping Extra (Innogenetics) on liquid cytology media EasyFix Labonord by comparing the extraction kit QIAamp DNA Blood Mini Kit (Qiagen) and an automated method, Nuclisens easyMAG (Biomérieux). METHODS: Thirty-two samples were typed by the technique Hybrid Capture 2 (HC2) Digene (Qiagen). DNA was extracted through manual or automated extraction and quality controlled PCR "HLA". Typing was performed with the INNO-LIPA test. A nested PCR followed by sequencing was used to compare different results. RESULTS: Similar results were found for the two types of extraction, with an increase of sensitivity after automated extraction. Among the nine patients with a negative result with the HC2 test, seven had a negative result in INNO-LIPA and two a positive result (one untypable and one HPV66). On the 23 patients with a positive result with the HC2 test, 17 are consistent results. The six discordant results include one negative, one HPV54, two untypable HPV and two HPV53. The overall concordance between the HC2 and INNO-LIPA tests is 81% with a kappa test of 0.79. CONCLUSION: Coupled with an automated extraction, the test INNO-LIPA confirmed its high sensitivity for detecting and typing HPV in the EasyFix media Labonord, especially in the presence of multiple genotypes. This typing systematic approach is becoming increasingly relevant in the context of HPV vaccination.

[Comparison between the LightCycler CMV Quant Kit (Roche Diagnostics) with a standardized in-house Taqman assay for cytomegalovirus blood viral load quantification]. / Comparaison de la trousse LightCycler CMV Quant Kit (Roche Diagnostics) avec une PCR "maison" standardisée pour la quantification du CMV sur sang total.

UNLABELLED: The broad use of cytomegalovirus (CMV) viral load quantification in blood to follow immunosuppressed patients need standardized assays. Choice of whole blood allows follow-up for several viruses and simplifies pretreatment and storage of samples. METHODS: We therefore evaluated the LightCycler CMV Quant Kit (Roche Diagnostics) assay on whole blood after a manual extraction (High Pure viral nucleic acid kit, Roche Diagnostics), using as a reference an in-house Taqman assay (LC1UL83) which has been validated in various clinical situations. A panel obtained by serial dilutions of a virion stock in CMV whole blood, a commercial plasma quality control (VQC, Argène, France) crude or diluted in whole blood, infected cells extracts and 46 clinical samples from transplanted patients were tested simultaneously by both techniques. RESULTS: For plasma quality controls, both PCR assays are correlated VQC (R(2)=0.93). On whole blood or infected cells dilutions, correlation shows an overestimation by the LC1UL83 assay (mean 1.2 log copies/ml) over 3 log though R(2)=0.94. Results with CMV Quant Kit are closer to expected values. Results on clinical samples are close to quality controls with a lower variation of quantification (0.76 log copies/ml). CONCLUSION: CMV Quant Kit performs well when compared with a clinically validated PCR. Quality control results showed discrepancies between plasma and whole blood, demonstrating the need for whole blood standardized panels to compare the methods. This underlines the need to follow a patient with the same technique during his follow-up.

Direct genotyping of cytomegalovirus envelope glycoproteins from toddler's saliva samples.

BACKGROUND: The polymorphism of genes encoding CMV envelope protein is used for strain classification and may influence pathogenesis and/or infectivity. CMV genotyping is usually based on sequencing or acrylamide gel-RFLP, but these methods are not suited to rapid screening of large populations. OBJECTIVES: We developed a high-throughput method to analyze CMV strains diversity and to detect multiple-strain infection in a large population of toddlers (six daycare centers (DCC) and an emergency unit (EU)). METHODS: We developed a new PCR-RFLP method coupled with capillary electrophoresis fragment detection for UL55-gB, UL75-gH and UL73-gN genotyping. To detect gB recombinants, gpUL55 typing was applied to two variable zones (NTerminal and central). We applied this method to 212 CMV-positive saliva samples and controlled the results by direct sequencing of PCR products. RESULTS: We identified 112 strains, that fell into eight groups in UL55-gB, two groups in UL75-gH, and seven groups in UL73-gN. The 79 samples from the emergency unit contained 30 strains, 28 children harboring 2 strains. The samples (n=133) from the six daycare centers contained respectively 4, 1, 6, 1 and 11 strains. Fifteen percent of strains were UL55-gB recombinants. CONCLUSION: Our new method can simultaneously determine gB, gH and gN genotypes and offers more precise classification of CMV strains than previous RFLP-based methods. This could constitute the basis for a new classification, particularly in UL55-gB. Easy direct identification of multiple strains and recombinants in pathological samples could facilitate large epidemiologic studies.

[Testing of a new probe 16/18/45 Hybrid Capture (Digene) in women with high risk HPV infection]. / Evaluation d'une sonde spécifique HPV 16, 18 et 45 Hybrid Capture (Digene) chez des patientes présentant une infection à HPV haut risque oncogène.

BACKGROUND: HPV HR detection test are needed when ASCUS is diagnosed on Pap test. The risk of progression to cervical cancer is dependant on the HPV genotype and three types (HPV 16, 18 and 45) are found in 77.4% of the cervical cancer. Here we have tested a new probe 16/18/45 (Digene) that is able to detect specifically these three types. MATERIAL AND METHODS: Thirty-seven women with a Hybrid Capture 2 High Risk test (Digene) positive were selected to test the new probe 16/18/45. Samples were typed using sequencing reaction after GP5+/GP6+ PCR. Types were given after comparison with the GenBank. Discordant results were controlled with Inno-Lipa HPV genotyping v2 test (Innogenetics). RESULTS: Among the 37 women with HR HPV result, 48.6% were positive with the probe 16/18/45 (18 patients). After genotyping, 12 results were concordant and six discordant (three HPV 31, two HPV 58 et one HPV 59). For the other 19 patients with negative result, 18 are concordant and one discordant (HPV 18). Global concordance for typing between this probe and sequencing was 81% with a kappa test of 0.62 that means a good concordance. Positive predictive value is 66.6% and negative predictive value is 94.7%. CONCLUSION: This study shows a good efficiency of the 16/18/45 probe to detect the genotypes that have the higher risk of progression to cervical cancer. This probe could also allow to follow the epidemiology of HR HPV infection after a large use of HPV vaccines.

[Evaluation of accuracy of three assays for human papillomavirus detection and typing: Hybrid Capture 2, HPV Consensus kit and Amplicor HPV]. / Evaluation des performances de trois techniques de détection et de typage des papillomavirus humains: Hybrid Capture 2, HPV Consensus kit et Amplicor HPV.

BACKGROUND: Detection of high-risk human papillomavirus has proved its usefulness in complement of abnormal cervical scrape result. The Hybrid Capture 2 (HC2, Digene) test has proven its efficiency. We have compared this test with HPV Consensus kit (HPVC, Argène) and Amplicor HPV test (AHPV, RocheDiagnostics) on a panel of 88 samples with low HC2 ratios or discordant results between HC2 and cervical scrape. MATERIAL AND METHODS: Cervical samples were tested in parallel by the three methods using a nested amplification of L1 region as reference. RESULTS: Eighty-six samples were suitable for analysis. Results of HC2 and AHPV tests were closely related. The use of a "generic" probe in the HPVC test was responsible for undetermined results, which were not clinically relevant. CONCLUSION: Despite the low viral load of the samples chosen, the hybridization (HC2) and PCR (AHPV or HPVC) methods gave comparable results, with false positive and false negative results for all tests, but a 75% concordance and a high sensibility to detect HPV infection. However, a complementary study on a larger population with ASCUS diagnosis and biopsy under colposcopy would be necessary to valid these assays for a clinical indication.

[Immunity and antiviral vaccinations. Example: the respiratory mucosa]. / Immunité et vaccinations antivirales : exemple de la muqueuse respiratoire.

OBJECTIVE: As the mucosal surfaces of the respiratory tract represent a major portal of entry for most human viruses and many bacteria, they seem to be a critical component of the mammalian immunologic repertoire. Thus, vaccines stimulating this local immunity could represent an interesting approach to prevent these infections. After detailing the different mechanisms implied in this mucosal immunity, the aim of this study is to analyze the basis of such a vaccination and the different vaccines available to mucosal respiratory tract use. MUCOSAL IMMUNITY: The major antibody isotype in external secretions is secretory immunoglobin A (S-IgA); the role of IgM (S-IgM) and IgG (S-IgG) are actually questionned. It is, however, interesting that the major effector cells in the mucosal surfaces are not IgA B cells, but T lymphocytes that may represent up to 80% of the entire mucosal lymphoid cell population. IMMUNOPROPHYLAXIS BY THE MUCOSAL ROUTE: Passive antibodies were shown to protect against mucosal viral infections, such as those caused by RSV, but very high quantities of passive antibodies are needed to restrict virus replication on mucosal surface.In general, factors which favor development of mucosal antibody and cell mediated immune responses include the oral or respiratory immunization and the replicating nature of the vaccine agents. However, to date only a few vaccines have become available to mucosal respiratory tract use, and cold-adapted influenza virus vaccines is the only one available using nasal route. Other parenteral licensed vaccines have not been recommended for mucosal administration. Some of them have been experimentally used with nasal administration of replicating agents (varicella and measles vaccines) or non replicating agents (influenza inactivated vaccine), but have been found to induce a very low mucosal response. CONCLUSION: Based on the experience with existing vaccines, the development of mucosal immunity or administration of vaccines via the mucosal route is clearly not a prerequisite today for control or prevention of most viral infectious respiratory diseases or diseases with respiratory tract as a route of contamination. But the example of live attenuated intranasal influenza vaccine inducing both systemic and local immune response without immunopathology, is promising for the future of the mucosal immunization against respiratory viral infections.

[Human papillomavirus prophylactic vaccines: stakes and perspectives]. / Vaccins prophylactiques antipapillomavirus: enjeux et perspectives.

Human Papillomavirus (HPV) infection is established as the necessary cause of cervical precancers and cancers. To date, more than 120 genotypes are known, but only high risk oncogen genotypes could induce a cancer. HPV 16 and 18 are implied in nearly 70% of cervical cancer around the world. Although some persistent HPV infections progress to cervical cancer, host immunity is generally able to clear most HPV infections providing an opportunity for cervical cancer prevention through vaccination. Candidate prophylactic vaccines based on papillomavirus L1 virus-like particles (VLPs) are currently on human clinical trials: one targeting cervical cancer with a bivalent VLP L1 vaccine containing the two genotypes most frequently involved in cervical cancer (type 16 and 18) and the other, protecting against warts as well as cervical cancer, with a quadrivalent HPV VLP L1 vaccine containing genotypes 6, 11, 16 and 18. The first clinical trials revealed the satisfactory tolerance and excellent immunogenicity of these vaccines inducing high serum antibody titers with minimal side effects. After more than three years, both clinical trials on women 15 to 25 years old have shown that vaccines are able to type specifically protect against nearly 90% of infection and all cervical intra-epithelial neoplasia. The vaccinal strategy defined to date targets preadolescents and adolescent young females (11-13 years) before the first sexual course but some questions are still not resolved concerning the prescriber, the actors of the vaccination and the duration of the protection. Nevertheless cervical cancer screening should be carried on for many years, even if a large vaccinal strategy is decided. Such a vaccine would save lives and reduce the need for costly medical procedures and the psychological stress induced by this cancer.