An industry update: the latest developments in therapeutic delivery covering May 2020.

The present industry update covers the period 1-31 May 2020, with information sourced from company press releases, regulatory and patent agencies as well as scientific literature.

Attenuated live infectious bronchitis virus QX vaccine disseminates slowly to target organs distant from the site of inoculation.

Infectious bronchitis (IB) is a highly contagious respiratory disease of poultry, caused by the avian coronavirus infectious bronchitis virus (IBV). Currently, one of the most relevant genotypes circulating worldwide is IBV-QX (GI-19), for which vaccines have been developed by passaging virulent QX strains in embryonated chicken eggs. Here we explored the attenuated phenotype of a commercially available QX live vaccine, IB Primo QX, in specific pathogens free broilers. At hatch, birds were inoculated with QX vaccine or its virulent progenitor IBV-D388, and postmortem swabs and tissues were collected each day up to eight days post infection to assess viral replication and morphological changes. In the trachea, viral RNA replication and protein expression were comparable in both groups. Both viruses induced morphologically comparable lesions in the trachea, albeit with a short delay in the vaccinated birds. In contrast, in the kidney, QX vaccine viral RNA was nearly absent, which coincided with the lack of any morphological changes in this organ. This was in contrast to high viral RNA titers and abundant lesions in the kidney after IBV D388 infection. Furthermore, QX vaccine showed reduced ability to reach and replicate in conjunctivae and intestines including cloaca, resulting in significantly lower titers and delayed protein expression, respectively. Nephropathogenic IBVs might reach the kidney also via an ascending route from the cloaca, based on our observation that viral RNA was detected in the cloaca one day before detection in the kidney. In the kidney distal tubular segments, collecting ducts and ureter were positive for viral antigen. Taken together, the attenuated phenotype of QX vaccine seems to rely on slower dissemination and lower replication in target tissues other than the site of inoculation.

Regulatory aspects of quality and safety for live recombinant viral vaccines against infectious diseases in Japan.

Recombinant viral vaccines expressing antigens of pathogenic microbes (e.g., HIV, Ebola virus, and malaria) have been designed to overcome the insufficient immune responses induced by the conventional vaccines. Our knowledge of and clinical experience with the new recombinant viral vaccines are insufficient, and a clear regulatory pathway is needed for the further development and evaluation of recombinant viral vaccines. In 2018, the research group supported by the Ministry of Health, Labour and Welfare, Japan (MHLW) published a concept paper to address the development of recombinant viral vaccines against infectious diseases. Herein we summarize the concept paper-which explains the Japanese regulatory concerns about recombinant viral vaccines-and provide a focus of discussion about the development of recombinant viral vaccines.

Determination of the minimum protective dose of a glycoprotein-G-deficient infectious laryngotracheitis virus vaccine delivered via eye-drop to week-old chickens.

Infectious laryngotracheitis (ILT) is an upper respiratory tract disease of chickens that is caused by infectious laryngotracheitis virus (ILTV), an alphaherpesvirus. This disease causes significant economic loses in poultry industries worldwide. Despite widespread use of commercial live attenuated vaccines, many poultry industries continue to experience outbreaks of disease caused by ILTV. Efforts to improve the control of this disease have resulted in the generation of new vaccine candidates, including ILTV mutants deficient in virulence factors. A glycoprotein G deletion mutant vaccine strain of ILTV (ΔgG ILTV), recently licenced as Vaxsafe ILT (Bioproperties Pty Ltd), has been extensively characterised in vitro and in vivo, but the minimum effective dose required to protect inoculated animals has not been determined. This study performed a vaccination and challenge experiment to determine the minimum dose of ΔgG ILTV that, when delivered by eye-drop to seven-day-old specific pathogen-free chickens, would protect the birds from a robust challenge with a virulent field strain of virus (class 9 ILTV). A dose of 10(3.8) plaque forming units was the lowest dose capable of providing a high level of protection against challenge, as measured by clinical signs of disease, tracheal pathology and virus replication after challenge. This study has shown that the ΔgG ILTV vaccine strain is capable of inducing a high level of protection against a virulent field virus at a commercially feasible dose. These results lay the foundations upon which a commercial vaccine can be developed, thereby offering the potential to provide producers with another important tool to help control ILTV.

Engineered Mesenchymal Cells Improve Passive Immune Protection Against Lethal Venezuelan Equine Encephalitis Virus Exposure.

UNLABELLED: : Mesenchymal stromal cells (MSCs) are being exploited as gene delivery vectors for various disease and injury therapies. We provide proof-of-concept that engineered MSCs can provide a useful, effective platform for protection against infectious disease. Venezuelan equine encephalitis virus (VEEV) is a mosquito-borne pathogen affecting humans and equines and can be used in bio-warfare. No licensed vaccine or antiviral agent currently exists to combat VEEV infection in humans. Direct antibody administration (passive immunity) is an effective, but short-lived, method of providing immediate protection against a pathogen. We compared the protective efficacy of human umbilical cord perivascular cells (HUCPVCs; a rich source of MSCs), engineered with a transgene encoding a humanized VEEV-neutralizing antibody (anti-VEEV), to the purified antibody. In athymic mice, the anti-VEEV antibody had a half-life of 3.7 days, limiting protection to 2 or 3 days after administration. In contrast, engineered HUCPVCs generated protective anti-VEEV serum titers for 21-38 days after a single intramuscular injection. At 109 days after transplantation, 10% of the mice still had circulating anti-VEEV antibody. The mice were protected against exposure to a lethal dose of VEEV by an intramuscular pretreatment injection with engineered HUCPVCs 24 hours or 10 days before exposure, demonstrating both rapid and prolonged immune protection. The present study is the first to describe engineered MSCs as gene delivery vehicles for passive immunity and supports their utility as antibody delivery vehicles for improved, single-dose prophylaxis against endemic and intentionally disseminated pathogens. SIGNIFICANCE: Direct injection of monoclonal antibodies (mAbs) is an important strategy to immediately protect the recipient from a pathogen. This strategy is critical during natural outbreaks or after the intentional release of bio-weapons. Vaccines require weeks to become effective, which is not practical for first responders immediately deployed to an infected region. However, mAb recipients often require booster shots to maintain protection, which is expensive and impractical once the first responders have been deployed. The present study has shown, for the first time, that mesenchymal stromal cells are effective gene delivery vehicles that can significantly improve mAb-mediated immune protection in a single, intramuscular dose of engineered cells. Such a cell-based delivery system can provide extended life-saving protection in the event of exposure to biological threats using a more practical, single-dose regimen.

Identification of an ideal adjuvant for receptor-binding domain-based subunit vaccines against Middle East respiratory syndrome coronavirus.

Middle East respiratory syndrome (MERS), an emerging infectious disease caused by MERS coronavirus (MERS-CoV), has garnered worldwide attention as a consequence of its continuous spread and pandemic potential, making the development of effective vaccines a high priority. We previously demonstrated that residues 377-588 of MERS-CoV spike (S) protein receptor-binding domain (RBD) is a very promising MERS subunit vaccine candidate, capable of inducing potent neutralization antibody responses. In this study, we sought to identify an adjuvant that optimally enhanced the immunogenicity of S377-588 protein fused with Fc of human IgG (S377-588-Fc). Specifically, we compared several commercially available adjuvants, including Freund's adjuvant, aluminum, Monophosphoryl lipid A, Montanide ISA51 and MF59 with regard to their capacity to enhance the immunogenicity of this subunit vaccine. In the absence of adjuvant, S377-588-Fc alone induced readily detectable neutralizing antibody and T-cell responses in immunized mice. However, incorporating an adjuvant improved its immunogenicity. Particularly, among the aforementioned adjuvants evaluated, MF59 is the most potent as judged by its superior ability to induce the highest titers of IgG, IgG1 and IgG2a subtypes, and neutralizing antibodies. The addition of MF59 significantly augmented the immunogenicity of S377-588-Fc to induce strong IgG and neutralizing antibody responses as well as protection against MERS-CoV infection in mice, suggesting that MF59 is an optimal adjuvant for MERS-CoV RBD-based subunit vaccines.

IPNV Antigen Uptake and Distribution in Atlantic Salmon Following Oral Administration.

One impediment to the successful oral vaccination in fish is the hostile stomach environment that antigens must cross. Furthermore, uptake of antigens from the gut to systemic distribution is required for induction of systemic immunity, the dynamics of which are poorly understood. In the present study, groups of Atlantic salmon parr were intubated with live or inactivated infectious pancreatic necrosis virus (IPNV), either orally or anally. At 1, 24 and 72 h post infection (p.i.), the fish were sacrificed. Serum was used for assessing IPNV by ELISA, while formalin-fixed head-kidney, spleen, liver and intestine tissues were used for the demonstration of antigens by immunohistochemistry. Both live and inactivated IPNV antigens were observed in enterocytes of the intestines and in immune cells of the head-kidneys and spleens of all groups. In the liver, no antigens were observed in any of the groups. Significantly higher serum antigen OD values (p < 0.04) were observed in orally- compared to anally-intubated fish. By contrast, no difference (p = 0.05) was observed in tissue antigens between these groups by immunohistochemistry. No significant difference (p = 0.05) in serum antigens was observed between groups intubated with live and inactivated IPNV, while in tissues, significantly more antigens (p < 0.03) were observe in the latter compared to the former. These findings demonstrate that both live and inactivated IPNV are taken up by enterocytes in the intestines of Atlantic salmon, likely by receptor-mediated mechanisms. Higher IPNV uptake by the oral compared to anal route suggests that both the anterior and posterior intestines are important for the uptake of the virus and that IPNV is resistant to gastric degradation of the Atlantic salmon stomach.

Distribution patterns of mucosally applied particles and characterization of the antigen presenting cells.

Mucosal application is the most common route of vaccination to prevent outbreaks of infectious diseases like Newcastle disease virus (NDV). To gain more knowledge about distribution and uptake of a vaccine after mucosal vaccination, we studied the distribution pattern of antigens after different mucosal routes of administration. Chickens were intranasally (i.n.), intratracheally (i.t.) or intraocularly (i.o.) inoculated with fluorescent beads and presence of beads in nasal-associated lymphoid tissue (NALT), Harderian gland (HG), conjunctiva-associated lymphoid tissue (CALT), trachea, lungs, air sacs, oesophagus and blood was characterized. The distribution patterns differed significantly between the three inoculation routes. After i.t. inoculation, the beads were mainly retrieved from trachea, NALT and lung. I.n. inoculation resulted in beads found mainly in NALT but detectable in all organs sampled. Finally, after i.o. inoculation, the beads were detected in NALT, CALT, HG and trachea. The highest number of beads was retrieved after i.n. inoculation. Development of novel vaccines requires a comprehensive knowledge of the mucosal immune system in birds in order to target vaccines appropriately and to provide efficient adjuvants. The NALT is likely important for the induction of mucosal immune responses. We therefore studied the phenotype of antigen-presenting cells isolated from NALT after i.n. inoculation with uncoated beads or with NDV-coated beads. Both types of beads were efficiently taken up and low numbers of bead+ cells were detected in all organs sampled. Inoculation with NDV-coated beads resulted in a preferential uptake by NALT antigen-presenting cells as indicated by high percentages of KUL01+-, MHC II+ and CD40+ bead+ cells.

Large intestine-targeted, nanoparticle-releasing oral vaccine to control genitorectal viral infection.

Both rectal and vaginal mucosal surfaces serve as transmission routes for pathogenic microorganisms. Vaccination through large intestinal mucosa, previously proven protective for both of these mucosal sites in animal studies, can be achieved successfully by direct intracolorectal (i.c.r.) administration, but this route is clinically impractical. Oral vaccine delivery seems preferable but runs the risk of the vaccine's destruction in the upper gastrointestinal tract. Therefore, we designed a large intestine-targeted oral delivery with pH-dependent microparticles containing vaccine nanoparticles, which induced colorectal immunity in mice comparably to colorectal vaccination and protected against rectal and vaginal viral challenge. Conversely, vaccine targeted to the small intestine induced only small intestinal immunity and provided no rectal or vaginal protection, demonstrating functional compartmentalization within the gut mucosal immune system. Therefore, using this oral vaccine delivery system to target the large intestine, but not the small intestine, may represent a feasible new strategy for immune protection of rectal and vaginal mucosa.

In vivo kinetics and biodistribution of a Hantaan virus DNA vaccine after intramuscular injection in mice.

To study the kinetics in vivo of a Hantaan virus DNA vaccine, we constructed a fusion DNA vaccine, pEGFP/S, by cloning the S segment of Hantavirus into the vector, pEGFP-C1, which encodes Green fluorescent protein EGFP. In this report, we provide evidence that pEGFP/S was distributed and persistently expressed for more than 60 days in several organs after inoculation. Our findings suggest that the persistent immune responses induced by a Hantaan virus DNA vaccine are likely due to the plasmid pEGFP/S deposited in vivo, which acts as a booster immunization.

Effect of mucosal and systemic immunization with virus-like particles of severe acute respiratory syndrome coronavirus in mice.

Nasal administration has emerged as a promising and attractive route for vaccination, especially for the prophylaxis of respiratory diseases. Our previous studies have shown that severe acute respiratory syndrome coronavirus (SARS-CoV) virus-like particles (VLPs) can be assembled using a recombinant baculovirus (rBV) expression system and such VLPs induce specific humoral and cellular immune responses in mice after subcutaneous injection. Here, we investigated mucosal immune responses to SARS-CoV VLPs in a mouse model. Mice were immunized in parallel, intraperitoneally or intranasally, with VLPs alone or with VLPs plus cytosine-phosphate-guanosine (CpG). Immune responses, including the production of SARS-CoV-specific serum immunoglobulin G (IgG) and secretory immunoglobulin A (sIgA), were determined in mucosal secretions and tissues. Both immunizations induced SARS-CoV-specific IgG, although the levels of IgG in groups immunized via the intraperitoneal (i.p.) route were higher. sIgA was detected in saliva in groups immunized intranasally but not in groups immunized intraperitoneally. CpG had an adjuvant effect on IgA production in genital tract washes when administered intranasally but only affected IgA production in faeces samples when administered intraperitoneally. In addition, IgA was also detected in mucosal tissues from the lung and intestine, while CpG induced an increased level of IgA in the intestine. Most importantly, neutralization antibodies were detected in sera after i.p. and intranasal (i.n.) immunizations. Secretions in genital tract washes from the i.n. group also showed neutralization activity. Furthermore, VLPs that were administered intraperitoneally elicited cellular immune responses as demonstrated by enzyme-linked immunospot (ELISPOT) assay analyses. In summary, our study indicates that mucosal immunization with rBV SARS-CoV VLPs represent an effective means for eliciting protective systemic and mucosal immune responses against SARS-CoV, providing important information for vaccine design.

GI-5005, a yeast vector vaccine expressing an NS3-core fusion protein for chronic HCV infection.

The HCV nonstructural protein 3 (NS3) and core protein are highly conserved among various HCV genotypes, and several B- and T-cell epitopes have been characterized with these antigens. The immunotherapeutic vaccine GI-5005, being developed by GlobeImmune Inc, is a Tarmogen (targeted molecular immunogen) consisting of recombinant Saccharomyces cerevisiae yeast expressing an HCV NS3-core fusion protein designed to elicit antigen-specific host CD4+ and CD8+ T-cell responses for the treatment of chronic HCV infection. GI-5005 has demonstrated robust immunogenicity in preclinical in vitro and in vivo models. In a phase Ib clinical trial, GI-5005 monotherapy was well tolerated and displayed efficacy in patients with chronic HCV infection. At the time of publication, interim data were available from a completed phase II trial that evaluated a triple therapy of GI-5005 in combination with the standard-of-care (SOC; PEGylated-IFNalpha and ribavirin) regimen, compared with the SOC regimen alone. Triple therapy resulted in improved early virological responses in all treatment-naïve patients. End-of-trial results, including data of sustained virological responses, are required to better evaluate the efficacy of GI-5005 for the improvement of viral clearance and to compare the efficacy of the agent with other approaches such as NS3 protease inhibitors.

Replication kinetics of duck virus enteritis vaccine virus in ducklings immunized by the mucosal or systemic route using real-time quantitative PCR.

A chicken embryo-adapted duck enteritis virus (DEV) strain is the most widely used vaccine against duck virus enteritis (DVE) infection. The kinetics of attenuated DEV vaccine was examined in tissues of ducklings vaccinated by the mucosal or systemic route at 20 days of age and sampled regularly up to 60 days post-vaccination (p.v.). Significant numbers of virus genomes in the lymphoid and other parenchymatous organs were first detected at 60 min p.v., and subsequently rose to peak levels during 90 min to 1 day p.v. independent of the route of vaccine administration. The peak level of vaccine virus in the individual parenchymatous organs of subcutaneously immunized ducklings was significantly higher than that of orally or nasally immunized ducklings. The route of vaccine administration had significant effect on the initial tissue distribution of vaccine virus in respiratory and digestive tracts. Vaccine viruses spread to digestive tract and trachea tissues by mucosal route, i.e. oral and nasal administration, early than that by subcutaneous route. The rapid early increase of vaccine virus levels in all samples examined followed by a steady decline from 90 min to 6 days p.v. The real-time PCR analysis of a variety of tissues is significant for further investigation of the mechanism of vaccinal protection, and the optimization of vaccination regimes.

Biodistribution and toxicological safety of adenovirus type 5 and type 35 vectored vaccines against human immunodeficiency virus-1 (HIV-1), Ebola, or Marburg are similar despite differing adenovirus serotype vector, manufacturer's construct, or gene inserts.

The Vaccine Research Center has developed vaccine candidates for different diseases/infectious agents (including HIV-1, Ebola, and Marburg viruses) built on an adenovirus vector platform, based on adenovirus type 5 or 35. To support clinical development of each vaccine candidate, pre-clinical studies were performed in rabbits to determine where in the body they biodistribute and how rapidly they clear, and to screen for potential toxicities (intrinsic and immunotoxicities). The vaccines biodistribute only to spleen, liver (Ad5 only), and/or iliac lymph node (Ad35 only) and otherwise remain in the site of injection muscle and overlying subcutis. Though approximately 10(11) viral particles were inoculated, already by Day 9, all but 10(3) to 10(5) genome copies per mu g of DNA had cleared from the injection site muscle. By three months, the adenovector was cleared with, at most, a few animals retaining a small number of copies in the injection site, spleen (Ad5), or iliac lymph node (Ad35). This pattern of limited biodistribution and extensive clearance is consistent regardless of differences in adenovector type (Ad5 or 35), manufacturer's construct and production methods, or gene-insert. Repeated dose toxicology studies identified treatment-related toxicities confined primarily to the sites of injection, in certain clinical pathology parameters, and in body temperatures (Ad5 vectors) and food consumption immediately post-inoculation. Systemic reactogenicity and reactogenicity at the sites of injection demonstrated reversibility. These data demonstrate the safety and suitability for investigational human use of Ad5 or Ad35 adenovector-based vaccine candidates at doses of up to 2 x 10(11) given intramuscularly to prevent various infectious diseases.

Kinetics of recombinant adenovirus type 5, vaccinia virus, modified vaccinia ankara virus, and DNA antigen expression in vivo and the induction of memory T-lymphocyte responses.

While a new generation of vaccine vectors has been developed for eliciting cellular immune responses, little is known about the optimal routes for their administration or about the ramifications of the kinetics of in vivo vaccine antigen expression for immunogenicity. We evaluated the kinetics of vaccine antigen expression by real-time in vivo photon imaging and showed dramatic differences in these kinetics using different vectors and different routes of administration. Further, using a gamma interferon enzyme-linked immunospot assay to measure T-lymphocyte immune responses, we observed an association between the kinetics of vaccine antigen expression in vivo and the magnitude of vaccine-elicited memory T-lymphocyte responses. These results highlight the utility of the real-time in vivo photon-imaging technology in evaluating novel immunization strategies and suggest an association between the kinetics of vaccine antigen clearance and the magnitude of vaccine-elicited T-lymphocyte memory immune responses.

Evidence based route of administration of vaccines.

Vaccination is a proven public health initiative, however it is imperative in the context of increasing concerns about vaccine induced adverse reactions and a decreasing incidence of diseases they prevent that the optimal route for their administration is defined. Traditionally all vaccines were given by subcutaneous injection until it was recognized that adjuvanted vaccines given via this route induced an unacceptable rate of injection site reaction. Evidence-based medicine has been championed as a way of improving the quality of patient care. Application of this methodology to the route of administration of vaccines demonstrates that vaccines should be given by intramuscular injection in preference to subcutaneous injection as the intramuscular route is associated with better immune response and a lower rate of injection site reaction. The basis of this superiority is discussed.

Lesiones y neoplasias del tracto genital femenino relacionadas con la infección por el virus del papiloma humano. Impacto previsible de la vacunación profiláctica / No disponible

“El descubrimiento de que el cáncer de cérvix es la rara consecuencia de una infecciónfrecuente ha sido tan impactante para la salud pública como la demostración de la asociaciónexistente entre el tabaco y el cáncer de pulmón.”Si bien la infección por virus del papiloma humano (VPH) desaparece espontáneamente lamayoría de las veces, desde el año 1999 sabemos que es el factor etiológico causante del cáncerde cérvix; posteriormente se ha demostrado su asociación no sólo con las lesiones precursorasde este tumor sino también con otras neoplasias y sus precursores de vulva, vagina, ano,pene y orofaringe. Asimismo está demostrado que determinados tipos de VPH son los causantesde procesos no neoplásicos como los condilomas genitales y la papilomatosis respiratoriarecurrente. En la presente revisión se analizan todos estos procesos, el papel etiopatogénico delos diferentes tipos de VPH, su incidencia, impacto sanitario y mortalidad, así como los procedimientosdiagnósticos y terapéuticos que conllevan.Mientras las lesiones neoplásicas se asocian fundamentalmente a la presencia de los llamadosVPH de alto riesgo basándose en su potencial carcinogenético (tipos más frecuentes:16 y 18), las lesiones no neoplásicas lo hacen a los VPH de bajo riesgo (tipos 6 y 11).La reciente aprobación de una vacuna tetravalente eficaz frente a estos cuatro tipos devirus (6, 11, 16 y 18) hace previsible un importante impacto a medio plazo sobre la incidenciay, por tanto, sobre la mortalidad asociada a ellos

“The discovery that cervical cancer is a rare consequence of a common infection is as momentous for public health as the demonstration of the association between cigarette smoking and lung cancer”. Most of the times the human papillomavirus (HPV) infection is cleared spontaneously,but since 1999 we know that it is the etiological factor for the cervical uterine cancer.Its association with cervical intraepithelial lesions and with other neoplasms and itsprecursors: vulvar, vaginal, penis, anal and nasopharyngeal carcinomas, has been demonstratedlater. The relationship between HPV and other non-cancerous conditions as anogenitalwarts and recurrent respiratory papillomatosis has also been demonstrated. In the presentarticle we review the burden, management and mortality of all these conditions andthe etiological role of different types of HPV.The cancerous conditions usually are associated with High Risk HPV Genotypes in relationto their carcinogenetic potential (the most frequent are 16 y 18) whereas the noncancerous ones are associated with low risk HPV (6, 11).The tetravalent HPV vaccine with proved efficacy against HPV types 6, 11, 16 and 18,has been approved recently with an important expected impact on its morbidity and mortality (AU)

Desarrollo de nuevas vacunas: vacuna frente al virus del papiloma humano. Criterios para su incorporación al programa de inmunización sistemática / No disponible

En las dos últimas décadas estamos asistiendo al desarrollo de nuevas vacunas gracias alos avances tecnológicos y la mejoría de la comprensión del sistema inmunitario y de las interaccionesde patógenos y huésped humano en el desarrollo de enfermedades. La infección porvirus del papiloma humano (VPH) es un claro ejemplo de esta última cuestión. Se sabe que lainfección persistente por algunos tipos de VPH de alto riesgo oncogénico constituye un factorcausal indispensable para el desarrollo del cáncer de cérvix. Este conocimiento ha permitidoel desarrollo de una estrategia de prevención primaria mediante vacunas profilácticas. De manerainminente, vamos a disponer en nuestro mercado de una vacuna para la prevención delVPH. La decisión de las autoridades sanitarias de incluirla o no en el calendario sistemáticodependerá del análisis de todos los factores implicados dentro de este problema de salud quese pretende prevenir. Los pediatras de Atención Primaria somos parte de la estructura que sustentael programa de vacunación. Como parte implicada en el proceso, es importante que conozcamoscuáles son los criterios que se evalúan. Este artículo analiza cada uno de estos criterios,utilizando como ejemplo la enfermedad por VPH y su vacuna, e intentando realizar unaaproximación a la perspectiva de salud pública

In the last two decades, a better knowledge of immune system and interactions betweenpathogens and human guest, involved in disease development, has proved to be crucial in theresearch of new vaccines. A good example of this has been the human papillomavirus (HPV)infection. Thus, high oncogenic risk types of HPV are involved in the development of cervix cancer. In those cases, a primary prevention strategy for HPV infection using prophylactic vaccines,plays an important role in prevention of future cervix cancer. The imminent marketingof HPV vaccine in our country, and its consequent inclusion in the Spanish ImmunizationSchedule, will depend on the results of the analysis of all impact factors in health burden. Weprimary care paediatricians are the final prescribers of vaccines, so we should know which criteriahave been evaluated by Sanitary Authorities. This paper analyzes each one of these criteriafor HPV vaccine

Efectividad e impacto de las vacunas frente al virus del papiloma humano / No disponible

El cáncer de cérvix constituye un problema de salud pública a nivel mundial de gran importancia.La infección por el virus del papiloma humano (VPH) está relacionada causalmentecon prácticamente la totalidad de los casos de cáncer de cérvix; también con una ciertacantidad de otros cánceres de mucosa genital, anal y orofaríngea, y casi la totalidad de lasverrugas genitales. El desarrollo de dos vacunas frente a la infección por el VPH abre la posibilidadde prevenir estas patologías; ambas vacunas contienen los VPH tipos 16 y 18, responsablesde, al menos, el 70% de los cánceres de cérvix. Además, la vacuna tetravalentecontiene los tipos 6 y 11 del VPH, responsables de, al menos, el 90% de las verrugas genitales.Los datos disponibles parecen indicar una alta eficacia protectora frente a las lesionesprecancerosas en mujeres jóvenes en estudios tras cinco años de observación; la vacuna tetravalentetambién protege eficazmente frente a las verrugas genitales. Sin embargo, quedanmuchos aspectos por aclarar relacionados con la efectividad real y el coste-beneficio de estasvacunas

Cervical cancer is a worldwide important public health problem. The infection by humanpapillomavirus (HPV) is causally related to almost every case of cervical cancer; also to a certainamount of other cancers of the genital, anal and nasopharyngeal mucosa, and almost allgenital warts. The development of two vaccines against the infection by HPV opens the possibilityof preventing these conditions; both vaccines contain HPV serotypes 16 and 18, responsibleof, at least, 70% of cervical cancers. Besides, the tetravalent vaccine contains the HPV serotypes6 and 11, responsible of, at least, 90% of genital warts.Data available seem to point to a high protective effect against precancerous lesions inyoung women in studies after five years of follow up; the tetravalent vaccine also gives effective protection against genital warts. Nevertheless, there still remain many aspects to be explainedrelated to the real effectiveness and cost-benefit of these vaccines