A phase 1/2a, dose-escalation, safety and preliminary efficacy study of oral therapeutic vaccine in subjects with cervical intraepithelial neoplasia 3

Current status and future directions for the development of human papillomavirus vaccines

The development of human papillomavirus (HPV) vaccines has made substantive progress, as represented by the approval of five prophylactic vaccines since 2006. Generally, the deployment of prophylactic HPV vaccines is effective in preventing newly acquired infections and incidences of HPV-related malignancies. However, there is still a long way to go regarding the prevention of all HPV infections and the eradication of established HPV infections, as well as the subsequent progression to cancer. Optimizing prophylactic HPV vaccines by incorporating L1 proteins from more HPV subtypes, exploring adjuvants that reinforce cellular immune responses to eradicate HPV-infected cells, and developing therapeutic HPV vaccines used either alone or in combination with other cancer therapeutic modalities might bring about a new era getting closer to the vision to get rid of HPV infection and related diseases. Herein, we summarize strategies for the development of HPV vaccines, both prophylactic and therapeutic, with an emphasis on the selection of antigens and adjuvants, as well as implications for vaccine efficacy based on preclinical studies and clinical trials. Additionally, we outline current cutting-edge insights on formulation strategies, dosing schedules, and age expansion among HPV vaccine recipients, which might play important roles in addressing barriers to vaccine uptake, such as vaccine hesitancy and vaccine availability.

Immunotherapy that leverages HPV-specific immune responses for precancer lesions of cervical cancer

Cervical cancer and its precursor lesion, cervical intraepithelial neoplasia (CIN), are caused by high-risk human papillomavirus (HPV) viral infection and are highly susceptible to host immunity targeting of HPV viral proteins, which include both foreign antigens and cancer antigens expressed by tumors. Immunotherapy that induces Th1 immunoreactivity against viral proteins is expected to take advantage of this immunological regression mechanism. However, although cancer immunotherapies for cervical cancer and CIN have been developed over the past several decades, none have been commercialized. Most of these immunotherapies target the viral cancer proteins E6 and E7, which are generally the same. The reasons for the underdevelopment of HPV-targeted immunotherapy differ depending on whether the target is invasive cancer or CIN. We here summarize the developmental history of cancer immunotherapy for CIN and discuss strategies for solving the problems that led to this underdevelopment. We note that CIN is a mucosal lesion and propose that inducing mucosal immunity may be the key.

Evaluation of Immune Response to Mucosal Immunization with an Oral Probiotic-Based Vaccine in Mice: Potential for Prime-Boost Immunization against SARS-CoV-2

Following the conclusion of the COVID-19 pandemic, the persistent genetic variability in the virus and its ongoing circulation within the global population necessitate the enhancement of existing preventive vaccines and the development of novel ones. A while back, we engineered an orally administered probiotic-based vaccine, L3-SARS, by integrating a gene fragment that encodes the spike protein S of the SARS-CoV-2 virus into the genome of the probiotic strain E. faecium L3, inducing the expression of viral antigen on the surface of bacteria. Previous studies demonstrated the efficacy of this vaccine candidate in providing protection against the virus in Syrian hamsters. In this present study, utilizing laboratory mice, we assess the immune response subsequent to immunization via the gastrointestinal mucosa and discuss its potential as an initial phase in a two-stage vaccination strategy. Our findings indicate that the oral administration of L3-SARS elicits an adaptive immune response in mice. Pre-immunization with L3-SARS enhances and prolongs the humoral immune response following a single subcutaneous immunization with a recombinant S-protein analogous to the S-insert of the coronavirus in Enterococcus faecium L3.

SARS-CoV-2 Spike Protein-Expressing Enterococcus for Oral Vaccination: Immunogenicity and Protection

The declaration of the conclusion of the COVID-19 pandemic notwithstanding, coronavirus remains prevalent in circulation, and the potential emergence of novel variants of concern introduces the possibility of new outbreaks. Moreover, it is not clear how quickly and to what extent the effectiveness of vaccination will decline as the virus continues to mutate. One possible solution to combat the rapidly mutating coronavirus is the creation of safe vaccine platforms that can be rapidly adapted to deliver new, specific antigens in response to viral mutations. Recombinant probiotic microorganisms that can produce viral antigens by inserting specific viral DNA fragments into their genome show promise as a platform and vector for mucosal vaccine antigen delivery. The authors of this study have developed a convenient and universal technique for inserting the DNA sequences of pathogenic bacteria and viruses into the gene that encodes the pili protein of the probiotic strain E. faecium L3. The paper presents data on the immunogenic properties of two E. faecium L3 vaccine strains, which produce two different fragments of the coronavirus S1 protein, and provides an assessment of the protective efficacy of these oral vaccines against coronavirus infection in Syrian hamsters.

Phase I and II randomized clinical trial of an oral therapeutic vaccine targeting human papillomavirus for treatment of cervical intraepithelial neoplasia 2 and 3

BACKGROUND

Although many human papillomavirus (HPV)-targeted therapeutic vaccines have been examined for efficacy in clinical trials, none have been translated into clinical use. These previous agents were mostly administered by intramuscular or subcutaneous injection to induce systemic immunity. We investigated the safety and therapeutic efficacy of an HPV-16 E7-expressing lacticaseibacillus-based oral vaccine.

METHODS

In a double-blind, placebo-controlled, randomized trial, a total of 165 patients with HPV-16-positive high-grade cervical intraepithelial neoplasia 2 and 3 were assigned to orally administered placebo or low, intermediate, or high doses of IGMKK16E7 (lacticaseibacillus paracasei expressing cell surface, full-length HPV-16 E7). In the 4 groups, IGMKK16E7 or placebo was administered orally at weeks 1, 2, 4, and 8 postenrollment. The primary outcomes included histopathological regression and IGMKK16E7 safety.

RESULTS

In per-protocol analyses, histopathological regression to normal (complete response) occurred in 13 (31.7%) of 41 high-dose recipients and in 5 (12.5%) of 40 placebo recipients (rate difference = 19.2, 95% confidence interval [CI] = 0.5 to 37.8). In patients positive for HPV-16 only, the clinical response rate was 40.0% (12 of 30) in high-dose recipients and 11.5% (3 of 26) in recipients of placebo (rate difference = 28.5, 95% CI = 4.3 to 50.0). There was no difference in adverse events that occurred in the high-dose and placebo groups (P = .83). The number of HPV-16 E7-specific interferon-γ producing cells within peripheral blood increased with level of response (stable disease, partial, and complete responses; P = .004). The regression to normal (complete response) rates among recipients with high levels of immune response were increased in a dose-dependent manner.

CONCLUSION

This trial demonstrates safety of IGMKK16E7 and its efficacy against HPV-16-positive cervical intraepithelial neoplasia 2 and 3. IGMKK16E7 is the first oral immunotherapeutic vaccine to show antineoplastic effects.

TRIAL REGISTRATION

jRCT2031190034.

Efficacy and safety of therapeutic HPV vaccines to treat CIN 2/CIN 3 lesions: a systematic review and meta-analysis of phase II/III clinical trials

OBJECTIVES

We aim to assess the efficacy and safety of therapeutic human papillomavirus (HPV) vaccines to treat cervical intraepithelial neoplasia of grade 2 or 3 (CIN 2/3).

DESIGN

Systematic review and meta-analysis, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations.

DATA SOURCES

PubMed, Embase, Web of Science, Global Index Medicus and CENTRAL Cochrane were searched up to 31 January 2022.

ELIGIBILITY CRITERIA

Phase II/III randomised controlled trials (RCTs) and single-arm studies reporting the efficacy of therapeutic vaccines to achieve regression of CIN 2/3 lesions were included. Studies evaluating only safety and side effects of the vaccine were excluded.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers extracted data and evaluated study quality. A random-effect model was used to pool the proportions of regression and/or HPV clearance.

RESULTS

12 trials met the inclusion criteria. Out of 734 women (all studies considered) receiving therapeutic HPV vaccine for CIN 2/3, 414 regressed to normal/CIN 1 with an overall proportion of regression of 0.54 (95% CI 0.39 to 0.69) for vaccinated group; 166 women (from five RCTs) receiving placebo only achieving a pooled normal/CIN 1 regression of 0.27 (95% CI 0.20 to 0.34). When including only the five two-arm studies, the regression proportion for the 410 vaccine group participants was higher than that of the 166 control group participants (relative risk (RR) 1.52; 95% CI 1.14 to 2.04). The pooled proportion of high-risk human papillomavirus (hrHPV) clearance was 0.42 (95% CI 0.32 to 0.52) in the vaccine group (six studies with a total of 357 participants) and 0.17 (95% CI 0.11 to 0.26) in the control group (three RCTs with a total of 104 participants). Based on these three RCTs, the hrHPV clearance was significantly higher in the vaccinated group (250 participants) compared with the control group (RR 2.03; 95% CI 1.30 to 3.16). Similar results were found regarding HPV 16/18 clearance. No significant unsolicited adverse events have been consistently reported.

CONCLUSIONS

The efficacy of the therapeutic vaccines in the treatment of CIN 2/3 was modest. Implementation issues such as feasibility, acceptability, adoption and cost-effectiveness need to be further studied.

PROSPERO REGISTRATION NUMBER

CRD42022307418.

The potential use of bacteria and bacterial derivatives as drug delivery systems for viral infection

Viral infections in humans are responsible for fatalities worldwide and contribute to the incidence of various human ailments. Controllable targeted medicine delivery against many illnesses, including viral infection, may be significantly aided by using bacteria and bacteria-derived products. They may accumulate in diseased tissues despite physical obstacles, where they can launch antiviral immunity. The ability to genetically and chemically modify them means that vaccinations against viral infections may be manufactured and delivered to affected tissues more safely and effectively. The objective of this study is to provide an overview of the latest advancements in the field of utilizing bacteria and bacterial derivatives as carriers for administering medication to treat viral diseases such as SARS-CoV-2, hepatitis B virus, hepatitis C virus, human immunodeficiency virus, human papillomavirus, influenza, and Ebola virus.

Human papillomavirus associated cervical lesion: pathogenesis and therapeutic interventions

Human papillomavirus (HPV) is the most prevalent sexually transmitted virus globally. Persistent high-risk HPV infection can result in cervical precancerous lesions and cervical cancer, with 70% of cervical cancer cases associated with high-risk types HPV16 and 18. HPV infection imposes a significant financial and psychological burden. Therefore, studying methods to eradicate HPV infection and halt the progression of precancerous lesions remains crucial. This review comprehensively explores the mechanisms underlying HPV-related cervical lesions, including the viral life cycle, immune factors, epithelial cell malignant transformation, and host and environmental contributing factors. Additionally, we provide a comprehensive overview of treatment methods for HPV-related cervical precancerous lesions and cervical cancer. Our focus is on immunotherapy, encompassing HPV therapeutic vaccines, immune checkpoint inhibitors, and advanced adoptive T cell therapy. Furthermore, we summarize the commonly employed drugs and other nonsurgical treatments currently utilized in clinical practice for managing HPV infection and associated cervical lesions. Gene editing technology is currently undergoing clinical research and, although not yet employed officially in clinical treatment of cervical lesions, numerous preclinical studies have substantiated its efficacy. Therefore, it holds promise as a precise treatment strategy for HPV-related cervical lesions.

Use of probiotic lactobacilli in the treatment of vaginal infections: In vitro and in vivo investigations

The vaginal microbiome is a distinct component of the human microbiome that is colonized by a wide variety of microorganisms. Lactobacilli are the most frequently identified microorganisms in the healthy human vagina. These Gram-positive bacilli can acidify the vaginal microenvironment, inhibit the proliferation of other pathogenic microorganisms, and promote the maintenance of a eubiotic vaginal microbiome. However, a vaginal flora with a reduced proportion or abundance of lactobacilli is associated with various vaginal infections that have been linked to serious health consequences such as infertility, preterm birth, pelvic inflammatory disease, premature rupture of membranes, and miscarriage. Due to their “Generally Recognized as Safe” classification and critical role in vaginal health, probiotic lactobacilli have been widely used as an alternative or adjunct to traditional antibiotic therapy for the treatment of vaginal infections and restoration of the vaginal microbiome. This review focuses on the significant role of probiotic lactobacilli in the vaginal microenvironment and discusses the use of probiotic lactobacilli in the treatment of female vaginal infections in vitro and in vivo.

The role of probiotics in vaginal health

Probiotics have been widely used in the treatment of intestinal diseases, but the effect of probiotics on female reproductive tract health is still controversial. Lactobacillus is the most abundant microorganism in the vagina, which is related to the vaginal mucosal barrier. Lactobacillus adheres to the vaginal epithelium and can competitively antagonize the colonization of pathogens. The factors produced by Lactobacillus, such as bacteriocin and hydrogen peroxide (H₂O₂), can inhibit the growth of pathogenic microorganisms and maintain the low pH environment of the vagina. Probiotics play an important role in maintaining the stability of vaginal microenvironment, improving immune defense and blocking the progression of cervical cancer. We review the research progress of probiotics represented by Lactobacillus in gynecological diseases such as human papilloma virus (HPV) infection, bacterial vaginosis (BV) and Genitourinary Syndrome of Menopause (GSM), so as to provide basis for further exerting the role of probiotics in women’s health.

Effectiveness and Safety of Therapeutic Vaccines for Precancerous Cervical Lesions: A Systematic Review and Meta-Analysis

Objective

This study systematically evaluated the effectiveness and safety of therapeutic vaccines for precancerous cervical lesions, providing evidence for future research.

Methods

We systematically searched the literature in 10 databases from inception to February 18, 2021. Studies on the effectiveness and safety of therapeutic vaccines for precancerous cervical lesions were included. Then, we calculated the overall incidence rates of four outcomes, for which we used the risk ratio (RR) and 95% confidence interval (95% CI) to describe the effects of high-grade squamous intraepithelial lesions (HSILs) on recurrence.

Results

A total of 39 studies were included, all reported in English, published from 1989 to 2021 in 16 countries. The studies covered 22,865 women aged 15-65 years, with a total of 5,794 vaccinated, and 21 vaccines were divided into six types. Meta-analysis showed that the overall incidence rate of HSIL regression in vaccine therapies was 62.48% [95% CI (42.80, 80.41)], with the highest rate being 72.32% for viral vector vaccines [95% CI (29.33, 99.51)]. Similarly, the overall incidence rates of HPV and HPV16/18 clearance by vaccines were 48.59% [95% CI (32.68, 64.64)] and 47.37% [95% CI (38.00, 56.81)], respectively, with the highest rates being 68.18% [95% CI (45.13, 86.14)] for bacterial vector vaccines and 55.14% [95% CI (42.31, 67.66)] for DNA-based vaccines. In addition, a comprehensive analysis indicated that virus-like particle vaccines after conization reduced the risk of HSIL recurrence with statistical significance compared to conization alone [RR = 0.46; 95% CI (0.29, 0.74)]. Regarding safety, only four studies reported a few severe adverse events, indicating that vaccines for precancerous cervical lesions are generally safe.

Conclusion

Virus-like particle vaccines as an adjuvant immunotherapy for conization can significantly reduce the risk of HSIL recurrence. Most therapeutic vaccines have direct therapeutic effects on precancerous lesions, and the effectiveness in HSIL regression, clearance of HPV, and clearance of HPV16/18 is great with good safety. That is, therapeutic vaccines have good development potential and are worthy of further research.

Systematic Review Registration

PROSPERO https://www.crd.york.ac.uk/PROSPERO/, CRD42021275452.

Potential effectiveness of a therapeutic HPV intervention campaign in Uganda

Cervical cancer is a major source of morbidity and mortality in Uganda. In addition to prophylactic HPV vaccination, secondary prevention strategies are needed to reduce cancer burden. We evaluated the potential cancer reductions associated with a hypothetical single-contact therapeutic HPV intervention-with 70% coverage and variable efficacy [30%-100%]-using a three-stage HPV modeling framework reflecting HPV and cervical cancer burden in Uganda. In the reference case, we assumed prophylactic preadolescent HPV vaccination starting in 2020 with 70% coverage. A one-time therapeutic intervention targeting 35-year-old women in 2025 (not age-eligible for prophylactic vaccination) averted 1801 cervical cancers per 100 000 women over their lifetime (100% efficacy) or 533 cancers per 100 000 (30% efficacy). Benefits were considerably smaller in birth cohorts eligible for prophylactic HPV vaccination (768 cases averted per 100 000 at 100% efficacy). Evaluating the population-level impact over 40 years, we found introduction of a therapeutic intervention in 2025 with 100% efficacy targeted annually to 30-year-old women averted 139 000 incident cervical cancers in Uganda. This benefit was greatly reduced if efficacy was lower (30% efficacy; 41 000 cases averted), introduction was delayed (2040 introduction; 72 000 cases averted) or both (22 000 cases averted). We demonstrate the potential benefits of a single-contact HPV therapeutic intervention in a low-income setting, but show the importance of high therapeutic efficacy and early introduction timing relative to existing prophylactic programs. Reduced benefits from a less efficacious intervention may be somewhat offset if available within a shorter time frame.

Recombinant lactic acid bacteria as promising vectors for mucosal vaccination

Lactic acid bacteria (LAB), a diverse family of gram-positive bacteria, has been proven effective in delivering varieties of therapeutic and prophylactic molecules such as antigens and cytokines. Featuring the properties of acid-resistant, high uptake into Peyer's patches, and superior capacity for inducing secretory IgA antibodies, LAB have good potential to be used as vaccine vectors for mucosal vaccination. Mucosal immunization enables both mucosal and systemic immune responses, which are critical for resisting pathogens that invade the host through the mucosal surfaces. With the development of genetic engineering, LAB strains, primarily Lactococcus and Lactobacillus have been exploited to express a range of heterologous antigens. Numerous studies have demonstrated that LAB mucosal vaccines can stimulate all arms of the immune system to provide adequate protection against pathogen infections. Additionally, several LAB-based human papillomavirus vaccines have entered the clinical trial studies, which suggest the great promise of LAB vaccines for new interventions in mucosal transport diseases. Herein, we will discuss the factors that influence the immunogenicity of LAB vaccines, including LAB strains, the location of antigens, and administration routes, and focus on the current strategies that have been reported for optimizing LAB vaccines.

Current Updates on Cancer-Causing Types of Human Papillomaviruses (HPVs) in East, Southeast, and South Asia

Simple Summary

Among the over 200 human papillomavirus (HPV) genotypes identified, approximately 15 of them can cause human cancers. In this review, we provided an updated overview of the distribution of cancer-causing HPV genotypes by countries in East, Southeast and South Asia. Besides the standard screening and treatment methods employed in these regions, we unravel HPV detection methods and therapeutics utilised in certain countries that differ from other part of the world. The discrepancies may be partly due to health infrastructure, socio-economy and cultural diversities. Additionally, we highlighted the area lack of study, particularly on the oncogenicity of HPV genotype variants of high prevalence in these regions.

Abstract

Human papillomavirus (HPV) infection remains one of the most prominent cancer-causing DNA viruses, contributing to approximately 5% of human cancers. While association between HPV and cervical cancers has been well-established, evidence on the attribution of head and neck cancers (HNC) to HPV have been increasing in recent years. Among the cancer-causing HPV genotypes, HPV16 and 18 remain the major contributors to cancers across the globe. Nonetheless, the distribution of HPV genotypes in ethnically, geographically, and socio-economically diverse East, Southeast, and South Asia may differ from other parts of the world. In this review, we garner and provide updated insight into various aspects of HPV reported in recent years (2015–2021) in these regions. We included: (i) the HPV genotypes detected in normal cancers of the uterine cervix and head and neck, as well as the distribution of the HPV genotypes by geography and age groups; (ii) the laboratory diagnostic methods and treatment regimens used within these regions; and (iii) the oncogenic properties of HPV prototypes and their variants contributing to carcinogenesis. More importantly, we also unveil the similarities and discrepancies between these aspects, the areas lacking study, and the challenges faced in HPV studies.

Probiotic-Based Vaccines May Provide Effective Protection against COVID-19 Acute Respiratory Disease

Severe acute respiratory syndrome coronavirus 2 virus (SARS-CoV-2) infection, the causative agent of COVID-19, now represents the sixth Public Health Emergency of International Concern (PHEIC)—as declared by the World Health Organization (WHO) since 2009. Considering that SARS-CoV-2 is mainly transmitted via the mucosal route, a therapy administered by this same route may represent a desirable approach to fight SARS-CoV-2 infection. It is now widely accepted that genetically modified microorganisms, including probiotics, represent attractive vehicles for oral or nasal mucosal delivery of therapeutic molecules. Previous studies have shown that the mucosal administration of therapeutic molecules is able to induce an immune response mediated by specific serum IgG and mucosal IgA antibodies along with mucosal cell-mediated immune responses, which effectively concur to neutralize and eradicate infections. Therefore, advances in the modulation of mucosal immune responses, and in particular the use of probiotics as live delivery vectors, may encourage prospective studies to assess the effectiveness of genetically modified probiotics for SARS-CoV-2 infection. Emerging trends in the ever-progressing field of vaccine development re-emphasize the contribution of adjuvants, along with optimization of codon usage (when designing a synthetic gene), expression level, and inoculation dose to elicit specific and potent protective immune responses. In this review, we will highlight the existing pre-clinical and clinical information on the use of genetically modified microorganisms in control strategies against respiratory and non-respiratory viruses. In addition, we will discuss some controversial aspects of the use of genetically modified probiotics in modulating the cross-talk between mucosal delivery of therapeutics and immune system modulation.

Efficacy of HPV Vaccination in Women Receiving LEEP for Cervical Dysplasia: A Single Institution's Experience

The aim of this study was to assess the role of a human papilloma virus (HPV) vaccine after loop electrosurgical excision procedure (LEEP) in reducing recurrent cervical dysplasia. A series of 503 women with cervical dysplasia received LEEP between January 2012 and October 2018. Of these patients, 379 were treated between January 2012 and June 2017, thus ensuring an adequate follow-up time. We made three attempts to establish telephone contact with each patient; 77 women did not respond and were excluded from the final study population, which consisted of 302 patients. One hundred eighty-two (60.7%) women were vaccinated with an HPV vaccine within 4 weeks of LEEP and 103 (34.3%) were followed up with but not vaccinated. Recurrence of cervical dysplasia requiring a further LEEP procedure occurred in 30 (10.5%) women, of whom 17 (16.5%) were not vaccinated and 13 (7.1%) were vaccinated (p-value = 0.010). At univariate analysis, HPV vaccination after LEEP (odds ratio (OR) = 0.4, p-value = 0.020) emerged as an independent protective factor. Choosing as an outcome of the analysis only recurrence as severe cervical lesions, the protective role of HPV vaccination after LEEP was found to be much more relevant with an odds ratio of 0.2 (95% CI = 0.1–0.6, p-value = 0.02). Administration of an HPV vaccine after LEEP seems to reduce the risk of recurrence, thus suggesting that HPV vaccination has a role as an adjuvant treatment after LEEP.