The efficacy and duration of vaccine protection against human papillomavirus: a systematic review and meta-analysis

Human papillomavirus prevalence and vaccine effectiveness in young women in Germany, 2017/2018: results from a nationwide study

Background

Infections with human papillomaviruses (HPV) are sexually transmitted and can cause cancer. In Germany, vaccination against HPV is recommended for girls and boys aged 9-17 years. We aimed to investigate HPV DNA prevalence, genotype distribution and vaccine effectiveness (VE) in women aged 20-25 years 10 years after the introduction of HPV vaccination in Germany (2018-2019), and compared these data to an equally designed study from 2010-2012.

Methods

Seventy six geographical clusters were randomly selected, followed by random selection of 61 women aged 20-25 years per cluster. Participants performed cervicovaginal self-sampling and answered questions on demographics, sexual behaviour and HPV vaccination. Samples were tested for 18 high risk and nine low risk HPV genotypes. We performed chi-square tests, Fisher's exact test, unpaired Student's t-test and proportion t-test, and calculated crude and adjusted prevalence ratios (PR) and 95% CIs.

Results

Of 7,858 contacted women a total of 1,226 agreed to participate. Of these, 94 women were positive for HPV types 16 and/or 18. HPV16 prevalence was 7.0% (95% CI 5.6-8.6) and HPV18 prevalence was 0.8% (95% CI 0.4-1.5). HPV6 and HPV11 were rare with only five (0.4%; 0.1-0.9) and one (0%; 95% CI 0.0-0.5) positive tests. Seven hundred fifty-seven women (62%) had received at least one HPV vaccine dose and 348 (28%) were vaccinated as currently recommended. Confounder-adjusted VE was 46.4% (95% CI 4.2-70.1) against HPV16/18 infection and 49.1% (95% CI 8.2-71.8) against infection with at least one HPV genotype covered by the quadrivalent HPV vaccine. Compared with the 2010-2012 study results, HPV16/18 prevalence dropped from 22.5% (95% CI 19.0-26.3) to 10.3% (95% CI 7.5-13.9; p < 0.0001) in unvaccinated participants.

Conclusion

Vaccine-covered HPV genotypes were rare among 20-25 years old women in Germany and decreased compared to the time point shortly after the start of the HPV vaccination program. HPV prevalence of almost all vaccine-covered genotypes was strongly reduced in vaccinated participants. A decrease of HPV16 and HPV18 was even observed in unvaccinated participants, compared to 2010-2012 data, suggesting indirect protection of unvaccinated women. Low VE against HPV16/18 and HPV6/11/16/18 in our study might be attributable to study design in combination with the endpoint selection of (mainly transient) HPV DNA positivity.

Can human papillomavirus vaccination during pregnancy result in miscarriage and stillbirth? A meta-analysis and systematic review

INTRODUCTION

Contradictory results regarding the safety of human papillomavirus (HPV) vaccination during pregnancy have been obtained, which has cast doubt on the use of this method. This review and meta-analysis were conducted to evaluate the safety of HPV vaccination during pregnancy.

METHODS

Complying with the inclusion and exclusion criteria, we searched Web of Science, Scopus, Medline, EMBASE, PubMed and Google Scholar databases for articles published in the past decade using the following keywords: 'papilloma human virus', 'HPV vaccine', 'pregnancy' and 'safety and prevention'. The minimum report quality of the articles was 16 based on the STROBE checklist.

RESULTS

Seven articles were included in the study, three of which were included in the meta-analysis, and the rest were reviewed systematically. The results of the meta-analysis showed that vaccination against HPV during pregnancy or around this period does not increase the risk of miscarriage (RR=2.01; 95% CI: 0.66-6.13) and stillbirth (RR=2.02: 95% CI: 0.65-6.27). No significant difference between miscarriage and stillbirth was observed in women vaccinated against HPV versus those not vaccinated.

CONCLUSIONS

The study of 1380424 individuals showed that HPV vaccination during pregnancy is better postponed until after this period. However, no significant evidence was found to indicate that vaccination was dangerous and unsafe during pregnancy. Further studies are needed to draw a more definitive conclusion.

HPV vaccination leads to decrease of anogenital warts and precancerous lesions of the cervix uteri in young women with low vaccination rates: a retrospective cohort analysis

BACKGROUND

Although the human papillomavirus (HPV) vaccine has been recommended in Germany for girls since 2007, no organised vaccination programme was introduced and HPV vaccine coverage remains low. We investigated the HPV vaccination rates from 2008 to 2018 and the effects of HPV vaccination on anogenital warts and precancerous lesions in young women in Bavaria, Germany, a state with low vaccination rates.

METHODS

Retrospective analyses of claims data from the Bavarian Association of Statutory Health Insurance Physicians (KVB) on females born between 1990 and 2009 (9 to 28 years old in 2018) were conducted to calculate vaccination rates by birth cohort, proportion of vaccine types administered and incidence of anogenital warts and precancerous lesions of the cervix uteri. 942 841 Bavarian females 9 to 28 years old with available information on HPV vaccination were included to calculate vaccination rates. For the outcome analyses, data from 433 346 females 19 to 28 years old were analysed. Hazard ratios (HR) were computed from univariable and multivariable Cox regression models comparing vaccinated and unvaccinated women, considering type of vaccine used and contraceptive prescription.

RESULTS

40·9% of 18-year-olds and only 13·3% of 12-year-olds were fully vaccinated in 2018 in Bavaria. Gardasil® and Gardasil9® were most commonly administered. Vaccinated compared to unvaccinated women had a lower incidence of anogenital warts and cervical lesions, however only small differences were detected between fully and partially vaccinated women. Fully vaccinated women had a 63% (HR 0·37 (95% confidence interval (CI) 0·34 to 0·40) and 23% (HR 0·77, 95%CI 0·71 to 0·84) lower risk of anogenital warts and cervical lesions, respectively. Women who were prescribed contraceptives prior to vaccination had a 49% higher risk of developing anogenital warts (HR 1·49, 95%CI 1·25 to 1·79) or cervical lesions (HR 1·49, 95%CI 1·27 to 1·75) compared to vaccinated women without contraceptive prescription.

CONCLUSIONS

The evaluation of the effects of HPV vaccination in Bavaria showed a promising decline of anogenital warts and precancerous lesions in vaccinated young women. However, an increase in vaccination rates is necessary to achieve a greater population impact in preventing HPV-related diseases.

[Vaccination against human papillomavirus]

Vaccination against human papillomavirus (HPV), which has been proven to be highly effective and safe, is recommended as part of standard vaccination by the German Standing Committee on Vaccination (STIKO) for 9‑ to 14-year-old girls and boys. Up to 90% of cervical cancer and its precancerous lesions can be prevented with timely vaccination (before first intercourse). In addition, the effectiveness extends to the primary prevention of HPV-associated neoplasms of the vulva, vagina, anus, penis and oropharynx. The HPV vaccination is the focus of the global initiative of the WHO calling on German health policymakers to significantly increase the immunization coverage of the German population, which is currently only 45-60%. Due to the high immunogenicity and the convincing long-term effects, the goals of eliminating cervical cancer and significantly reducing other HPV-associated cancers are theoretically achievable.

Awareness and knowledge of human papillomavirus vaccination and their influential factors among Chinese women: a systematic review

Objectives

To systematically review the knowledge attitudes and the influential factors on human papillomavirus (HPV) vaccination among Chinese women.

Methods

Published studies on knowledge and attitudes of HPV vaccination for preventing cervical cancer among Chinese female population were retrieved using the major Chinese and English databases. Meanwhile, handwork retrieval was also conducted and the references including in the literature were retrieved. The quality of the literature was rigorously evaluated and extracted independently by two researchers and the data were analyzed and described by review manager 5.3 (RevMan5.3) software.

Results

In all, 19 articles including 8 articles in Chinese and 11 in English were chosen. A total of 30,176 participants were included and the sample size ranged from 64 to 6,024. The overall awareness of HPV and HPV vaccine among Chinese women was at a low level. Chinese women generally showed poor knowledge about HPV and HPV vaccine. Acceptance of HPV vaccination among Chinese women was at a high level. Vaccination intentions were influenced by the theory of planned behavior (TPB) and measured by attitudes subjective norms and perceived behavioral control.

Conclusions

The health authorities may evaluate and develop TPB-based interventions to increase HPV vaccination intentions of Chinese women. HPV vaccination programs should focus on carrying out multi-level and targeted health education and developing effective public health strategies after balancing the cost and benefit of HPV vaccine program. Medical staff should play the positive role in promoting the use of HPV vaccines in China. Integration of policy and community perspectives and multi-level interventions are essential to maximize the public health benefits of HPV vaccination.

[The new standard operating procedure of the German standing committee on vaccination (STIKO): history, structure, and implementation]

In Germany, the Standing Committee on Vaccination (STIKO) develops recommendations on vaccinations and other measures of specific prophylaxis against communicable diseases. Myths, wrong assumptions, and conspiracy theories are able to disturb the implementation of vaccination recommendations. Evidence and transparency of recommendations are needed to rationalize the discussion.In November 2011, STIKO adopted a new standard operating procedure (SOP) for the development of evidence-based vaccination recommendations. Following guidance provided by the SOP, a number of new vaccination recommendations have been developed since 2011. Furthermore, existing recommendations were revised or extended accordingly. This article provides an overview on the methodology of the SOP, describes experiences made so far, and characterizes future challenges.

Efficacy, effectiveness and safety of vaccination against human papillomavirus in males: a systematic review

BACKGROUND

Human papillomavirus (HPV) vaccination is safe and effective in preventing cervical cancer in females. As HPV infections can also induce cancers of the anus, penis and oral cavity, male vaccination is also advocated, but systematic reviews on efficacy and safety in males are lacking.

METHODS

We performed a systematic review on the efficacy, effectiveness and safety of HPV vaccination in males of any age. MEDLINE, Embase, the Cochrane Central Register of Controlled Trials and ClinicalTrials.gov were searched from inception to April 2017.

RESULTS

We identified 5196 articles and seven studies (four randomized controlled trials (RCTs), three non-randomized studies) were included, comprising a total of 5294 participants. Vaccine efficacy against at least 6-month persisting anogenital HPV 16 infections was 46.9% (95% confidence interval (CI) 28.6-60.8%), whereas efficacy against persisting oral infections was 88% (2-98%). A vaccine efficacy of 61.9% (21.4-82.8%) and 46.8% (- 20 to -77.9%) was observed against anal intraepithelial neoplasia grade 2 and grade 3 lesions, respectively. No meaningful estimates were available on vaccine efficacy or effectiveness against penile intraepithelial neoplasia grade 2 or 3, and no data were identified for anal, penile or head and neck squamous cell cancer. In participants who were HPV-seronegative and PCR-negative at enrolment, efficacy against all outcomes was higher as compared to seropositive and/or PCR-positive individuals. Risk of bias was low in three RCTs and high in one, while the three non-randomized studies were at serious to critical risk of bias. Grading of Recommendations Assessment, Development and Evaluation evidence quality was moderate to low for most outcomes.

CONCLUSIONS

HPV vaccination in males is moderately effective against persistent anogenital HPV infection and high-grade anal intraepithelial lesions in studies where the population consists mainly of HPV-infected males. Vaccine effectiveness was high in study groups comprising HPV-naïve males. This supports a recommendation for vaccination of boys before the onset of sexual activity with the goal of establishing optimal vaccine-induced protection. Mathematical modelling studies will still be needed to assess the effects of adding males to existing HPV vaccination programs in females.

TRIAL REGISTRATION

Prospective Register for Systematic Reviews (PROSPERO) registration CRD42016038965 .

Advancing the public health applications of Chlamydia trachomatis serology

Genital Chlamydia trachomatis infection is the most commonly diagnosed sexually transmitted infection. Trachoma is caused by ocular infection with C trachomatis and is the leading infectious cause of blindness worldwide. New serological assays for C trachomatis could facilitate improved understanding of C trachomatis epidemiology and prevention. C trachomatis serology offers a means of investigating the incidence of chlamydia infection and might be developed as a biomarker of scarring sequelae, such as pelvic inflammatory disease. Therefore, serological assays have potential as epidemiological tools to quantify unmet need, inform service planning, evaluate interventions including screening and treatment, and to assess new vaccine candidates. However, questions about the performance characteristics and interpretation of C trachomatis serological assays remain, which must be addressed to advance development within this field. In this Personal View, we explore the available information about C trachomatis serology and propose several priority actions. These actions involve development of target product profiles to guide assay selection and assessment across multiple applications and populations, establishment of a serum bank to facilitate assay development and evaluation, and development of technical and statistical methods for assay evaluation and analysis of serological findings. The field of C trachomatis serology will benefit from collaboration across the public health community to align technological developments with their potential applications.

Prophylactic vaccination against human papillomaviruses to prevent cervical cancer and its precursors

BACKGROUND

Persistent infection with high-risk human papillomaviruses (hrHPV) types is causally linked with the development of cervical precancer and cancer. HPV types 16 and 18 cause approximately 70% of cervical cancers worldwide.

OBJECTIVES

To evaluate the harms and protection of prophylactic human papillomaviruses (HPV) vaccines against cervical precancer and HPV16/18 infection in adolescent girls and women.

SEARCH METHODS

We searched MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL) and Embase (June 2017) for reports on effects from trials. We searched trial registries and company results' registers to identify unpublished data for mortality and serious adverse events.

SELECTION CRITERIA

Randomised controlled trials comparing efficacy and safety in females offered HPV vaccines with placebo (vaccine adjuvants or another control vaccine).

DATA COLLECTION AND ANALYSIS

We used Cochrane methodology and GRADE to rate the certainty of evidence for protection against cervical precancer (cervical intraepithelial neoplasia grade 2 and above [CIN2+], CIN grade 3 and above [CIN3+], and adenocarcinoma-in-situ [AIS]), and for harms. We distinguished between the effects of vaccines by participants' baseline HPV DNA status. The outcomes were precancer associated with vaccine HPV types and precancer irrespective of HPV type. Results are presented as risks in control and vaccination groups and risk ratios (RR) with 95% confidence intervals in brackets.

MAIN RESULTS

We included 26 trials (73,428 participants). Ten trials, with follow-up of 1.3 to 8 years, addressed protection against CIN/AIS. Vaccine safety was evaluated over a period of 6 months to 7 years in 23 studies. Studies were not large enough or of sufficient duration to evaluate cervical cancer outcomes. All but one of the trials was funded by the vaccine manufacturers. We judged most included trials to be at low risk of bias. Studies involved monovalent (N = 1), bivalent (N = 18), and quadrivalent vaccines (N = 7). Most women were under 26 years of age. Three trials recruited women aged 25 and over. We summarize the effects of vaccines in participants who had at least one immunisation.Efficacy endpoints by initial HPV DNA statushrHPV negativeHPV vaccines reduce CIN2+, CIN3+, AIS associated with HPV16/18 compared with placebo in adolescent girls and women aged 15 to 26. There is high-certainty evidence that vaccines lower CIN2+ from 164 to 2/10,000 (RR 0.01 (0 to 0.05)) and CIN3+ from 70 to 0/10,000 (RR 0.01 (0.00 to 0.10). There is moderate-certainty evidence that vaccines reduce the risk of AIS from 9 to 0/10,000 (RR 0.10 (0.01 to 0.82).HPV vaccines reduce the risk of any CIN2+ from 287 to 106/10,000 (RR 0.37 (0.25 to 0.55), high certainty) and probably reduce any AIS lesions from 10 to 0/10,000 (RR 0.1 (0.01 to 0.76), moderate certainty). The size of reduction in CIN3+ with vaccines differed between bivalent and quadrivalent vaccines (bivalent: RR 0.08 (0.03 to 0.23), high certainty; quadrivalent: RR 0.54 (0.36 to 0.82), moderate certainty). Data in older women were not available for this comparison.HPV16/18 negativeIn those aged 15 to 26 years, vaccines reduce CIN2+ associated with HPV16/18 from 113 to 6 /10,000 (RR 0.05 (0.03 to 0.10). In women 24 years or older the absolute and relative reduction in the risk of these lesions is smaller (from 45 to 14/10,000, (RR 0.30 (0.11 to 0.81), moderate certainty). HPV vaccines reduce the risk of CIN3+ and AIS associated with HPV16/18 in younger women (RR 0.05 (0.02 to 0.14), high certainty and RR 0.09 (0.01 to 0.72), moderate certainty, respectively). No trials in older women have measured these outcomes.Vaccines reduce any CIN2+ from 231 to 95/10,000, (RR 0.41 (0.32 to 0.52)) in younger women. No data are reported for more severe lesions.Regardless of HPV DNA statusIn younger women HPV vaccines reduce the risk of CIN2+ associated with HPV16/18 from 341 to 157/10,000 (RR 0.46 (0.37 to 0.57), high certainty). Similar reductions in risk were observed for CIN3+ associated with HPV16/18 (high certainty). The number of women with AIS associated with HPV16/18 is reduced from 14 to 5/10,000 with HPV vaccines (high certainty).HPV vaccines reduce any CIN2+ from 559 to 391/10,000 (RR 0.70 (0.58 to 0.85, high certainty) and any AIS from 17 to 5/10,000 (RR 0.32 (0.15 to 0.67), high certainty). The reduction in any CIN3+ differed by vaccine type (bivalent vaccine: RR 0.55 (0.43 to 0.71) and quadrivalent vaccine: RR 0.81 (0.69 to 0.96)).In women vaccinated at 24 to 45 years of age, there is moderate-certainty evidence that the risks of CIN2+ associated with HPV16/18 and any CIN2+ are similar between vaccinated and unvaccinated women (RR 0.74 (0.52 to 1.05) and RR 1.04 (0.83 to 1.30) respectively). No data are reported in this age group for CIN3+ or AIS.Adverse effectsThe risk of serious adverse events is similar between control and HPV vaccines in women of all ages (669 versus 656/10,000, RR 0.98 (0.92 to 1.05), high certainty). Mortality was 11/10,000 in control groups compared with 14/10,000 (9 to 22) with HPV vaccine (RR 1.29 [0.85 to 1.98]; low certainty). The number of deaths was low overall but there is a higher number of deaths in older women. No pattern in the cause or timing of death has been established.Pregnancy outcomesAmong those who became pregnant during the studies, we did not find an increased risk of miscarriage (1618 versus 1424/10,000, RR 0.88 (0.68 to 1.14), high certainty) or termination (931 versus 838/10,000 RR 0.90 (0.80 to 1.02), high certainty). The effects on congenital abnormalities and stillbirths are uncertain (RR 1.22 (0.88 to 1.69), moderate certainty and (RR 1.12 (0.68 to 1.83), moderate certainty, respectively).

AUTHORS' CONCLUSIONS

There is high-certainty evidence that HPV vaccines protect against cervical precancer in adolescent girls and young women aged 15 to 26. The effect is higher for lesions associated with HPV16/18 than for lesions irrespective of HPV type. The effect is greater in those who are negative for hrHPV or HPV16/18 DNA at enrolment than those unselected for HPV DNA status. There is moderate-certainty evidence that HPV vaccines reduce CIN2+ in older women who are HPV16/18 negative, but not when they are unselected by HPV DNA status.We did not find an increased risk of serious adverse effects. Although the number of deaths is low overall, there were more deaths among women older than 25 years who received the vaccine. The deaths reported in the studies have been judged not to be related to the vaccine. Increased risk of adverse pregnancy outcomes after HPV vaccination cannot be excluded, although the risk of miscarriage and termination are similar between trial arms. Long-term of follow-up is needed to monitor the impact on cervical cancer, occurrence of rare harms and pregnancy outcomes.

Psychiatric conditions and general practitioner attendance prior to HPV vaccination and the risk of referral to a specialized hospital setting because of suspected adverse events following HPV vaccination: a register-based, matched case-control study

AIM

No association between human papilloma virus (HPV) vaccination and numerous diseases has been found. Still, a large number of Danish women are reporting suspected adverse events. Other factors may play a role, and the aim of this study is to examine the association between psychiatric conditions, general practitioner (GP) attendance and indicators of psychological symptoms prior to HPV vaccination and the risk of referral to an HPV center following vaccination.

STUDY DESIGN AND SETTING

Register-based, matched case-control study. Cases were identified from five Danish, regional HPV centers, and health data for cases and controls were obtained from national registries.

PARTICIPANTS

Cases were defined as women referred to an HPV center between January 1, 2015 and December 31, 2015 (n=1,496). Each case was matched with five controls on age, region and time of first vaccine registration. The total study population consisted of 8,976 women.

RESULTS

Overall, women above 18 years who had been referred to an HPV center were more likely to have used psychiatric medication (odds ratio [OR]: 1.88 [95% CI 1.48-2.40]) or to have been hospitalized because of a psychiatric disorder within 5 years prior to the first vaccine registration (OR: 2.13 [95% CI 1.59-2.86]). Specifically, referred women were more likely to have used antipsychotics, antidepressants, attention deficit hyperactivity disorder (ADHD) medication or anxiolytics, and to have been hospitalized for affective disorders or anxiety, but not to have been hospitalized for schizoid, ADHD or eating disorders. In addition, they were more likely to have had talk therapy or psychometric test performed prior to vaccination (OR: 1.72 [95% CI 0.1.35-2.18] and OR: 1.67 [95% CI 1.30-2.13], respectively). Referred women of all ages had higher use of GP before vaccination. Population attributable fraction analyses indicated that psychiatric medication, hospitalization due to a psychiatric disorder and use of talk therapy, or psychometric test "explained" 13%, 10%, 12% and 11% of the referrals, respectively. Results did not change substantially when adjusted for potential confounders.

CONCLUSION

Women referred to HPV centers because of suspected adverse events after vaccination more often had preexisting psychiatric conditions, psychological symptoms or frequent GP attendance prior to HPV vaccination.

Cost-effectiveness of human papillomavirus vaccination in Germany

BACKGROUND

The aim of this study was to assess the cost-effectiveness of human papillomavirus (HPV) vaccination in addition to the current cervical cancer screening programme in Germany using a dynamic transmission model.

METHODS

Based on a mathematical model simulating the transmission dynamics and the natural history of HPV infection and associated diseases (cervical intraepithelial neoplasia, cervical cancer, and genital warts), we estimated the epidemiological and economic consequences of HPV vaccination with both the quadrivalent and bivalent vaccines. In our base case analysis, we assessed the cost-effectiveness of vaccinating 12-year-old girls with a 3-dose schedule. In sensitivity analysis, we also evaluated the use of a 2-dose schedule and assessed the impact of vaccinating boys.

RESULTS

From a health care payer perspective, incremental cost-effectiveness ratios (ICERs) of a 3-dose schedule were €34,249 per quality-adjusted life year (QALY) for the bivalent and €14,711 per QALY for the quadrivalent vaccine. Inclusion of indirect costs decreased ICERs by up to 40%. When adopting a health care payer perspective, ICERs of a 2-dose approach decreased to €19,450 per QALY for the bivalent and to €3645 per QALY for the quadrivalent vaccine. From a societal perspective, a 2-dose approach using the quadrivalent vaccine was a cost-saving strategy while using the bivalent vaccine resulted in an ICER of €13,248 per QALY. Irrespective of the perspective adopted, additional vaccination of boys resulted in ICERs exceeding €50,000 per QALY, except for scenarios with low coverage (20%) in girls.

CONCLUSIONS

Our model results suggest that routine HPV vaccination of 12-year-old girls with three doses is likely to be cost-effective in Germany. Due to the additional impact on genital warts, the quadrivalent vaccine appeared to be more cost-effective than the bivalent vaccine. A 2-dose schedule of the quadrivalent vaccine might even lead to cost savings when adopting a societal perspective. The cost-effectiveness of additional vaccination of boys was highly dependent on the coverage in girls.

Porcine epidemic diarrhea virus virus-like particles produced in insect cells induce specific immune responses in mice

Porcine epidemic diarrhea virus (PEDV), which causes 80-100% mortality in neonatal piglets, is one of the most devastating viral diseases affecting swine worldwide. To date, the lack of effective vaccines and drugs is the main problem preventing control of the global spread of PEDV. In this study, we produced PEDV virus-like particles (VLPs) composed of S, M, and E proteins with a baculovirus expression system and tested them via indirect immunofluorescence assay (IFA)and Western blot analysis. Electron microscopy showed that the morphological structure of the PEDV VLPs was similar to that of the protovirus. Microneutralization assays and ELISpot analysis demonstrated that PEDV VLPs induced highly specific antibody responses and Th2-mediated humoral immunity. As a result, the PEDV VLPs displayed excellent immunogenicity in mice. Therefore, a VLP-based vaccine has the potential to prevent PEDV infection.

Kaposi's sarcoma-associated herpesvirus stably clusters its genomes across generations to maintain itself extrachromosomally

Several human tumor viruses, including Kaposi’s sarcoma–associated herpesvirus (KSHV), maintain their plasmid genomes by tethering them to cellular chromosomes. Chiu et al. identify a viral segregation mechanism: KSHV stably clusters some of its genomes, which are inherited as units. Clustering, as predicted computationally and observed in live cells, rapidly establishes high viral copy numbers in cells.

Genetic elements that replicate extrachromosomally are rare in mammals; however, several human tumor viruses, including the papillomaviruses and the gammaherpesviruses, maintain their plasmid genomes by tethering them to cellular chromosomes. We have uncovered an unprecedented mechanism of viral replication: Kaposi’s sarcoma–associated herpesvirus (KSHV) stably clusters its genomes across generations to maintain itself extrachromosomally. To identify and characterize this mechanism, we developed two complementary, independent approaches: live-cell imaging and a predictive computational model. The clustering of KSHV requires the viral protein, LANA1, to bind viral genomes to nucleosomes arrayed on both cellular and viral DNA. Clustering affects both viral partitioning and viral genome numbers of KSHV. The clustering of KSHV plasmids provides it with an effective evolutionary strategy to rapidly increase copy numbers of genomes per cell at the expense of the total numbers of cells infected.

Naprotecnología: ciencia y persona en la infección por el virus del papiloma humano (VPH) en mujeres y preadolescencentes

En la actualidad hay suficiente evidencia científica que relaciona directamente adquisición, exposición y prevalencia del virus del papiloma humano (VPH) con el cáncer del cuello de uterino. Por ello, el artículo aborda el VPH en la mujer teniendo en cuenta la naprotecnología, que permite conjugar evidencia científica y planteamientos éticos. Se busca que se tengan en cuenta tanto el aspecto biológico de la sexualidad como la capacidad de hacerse persona en su núcleo sexual. De ahí que se analicen programas dirigidos a la educación sexual, basados tanto en la prevención sanitaria como en la antropología de la sexualidad, y apoyados por las instituciones familiares, que han demostrado una mejor acogida ante los riesgos de las enfermedades de transmisión sexual, y entre ellas la infección por el VPH.

The differential diagnosis and interdisciplinary treatment of anal carcinoma

BACKGROUND

Anal carcinoma accounts for 2-4% of all cases of colorectal and anorectal carcinoma. Its peak incidence is from age 58 to age 64; women are affected somewhat more commonly than men. Its incidence has risen markedly in the past three decades.

METHODS

This article is based on a selective review of the literature, including the guidelines of the National Comprehensive Cancer Network and the European Society of Medical Oncology.

RESULTS

Anal carcinoma is often an incidental finding. About 85% of newly diagnosed cases are associated with an HPV infection with strain 16, 18, or 33. Radiochemotherapy with 5-fluorouracil and mitomycin C is the treatment of choice. The 5-year survival rate is 80-90%. Primary surgery with curative intent is indicated only for well-differentiated carcinoma of the anal margin (T1, N0). 10-30% of patients now undergo radical resection. The utility of endosonography and positron emission tomography for staging is debated and needs further study.

CONCLUSION

The treatment of patients with anal carcinoma requires a specialized multidisciplinary approach in accordance with the current evidence-based guidelines. The potential role of prophylactic vaccination against oncogenic types of HPV in the prevention of anal carcinoma merits further investigation.