Low antigen immunogenicity poses a significant challenge in vaccine development, often leading to inadequate immune responses and reduced vaccine efficacy. Therefore, the discovery of potent immune-enhancing adjuvants is crucial. STING (stimulator of interferon genes) agonists are a promising class of adjuvants which have been identified in various immune cells and are activated in response to DNA fragments, triggering a broad range of type-I interferon-dependent immune responses. Integrating STING agonists with vaccine components is an ideal strategy to bolster vaccine-induced immunity to infections and cancer cells. Several STING agonists are currently under investigation in preclinical studies and clinical trials; however, some have shown limited efficacy, while others exhibit off-target effects. To ensure safety, they are typically delivered with carriers that exhibit high biocompatibility and insolubility. In this review, we present the latest research on natural and synthetic STING agonists that have been effectively used in vaccine development, and summarize their application in adjuvant preventive and therapeutic vaccines. Additionally, we discuss the safety of STING agonists as vaccine adjuvants by reviewing potential delivery strategies. Overall, incorporating STING agonists into vaccine formulations represents a significant advancement in vaccine research with the potential to significantly enhance immune responses and improve vaccine efficacy. However, ongoing research is still required to identify the most effective and safe delivery strategies for STING agonists, as well as to evaluate their long-term safety and efficacy in clinical trials.

Chronic hepatitis E virus (HEV) infection is frequently reported in immunocompromised patients, but has also been increasingly reported in non-immunocompromised individuals. We characterized the course of chronic HEV infection in immunocompetent rabbits. In two independent experiments, 40 specific-pathogen-free rabbits were infected with a rabbit HEV genotype 3 strain in serial diluted titers (10⁸ to 10⁴ copies/mL). Serum and fecal samples were collected weekly and were tested for HEV RNA, antigen, anti-HEV and liver enzymes. Rabbits that spontaneously cleared the infection before 10 weeks post-inoculation (wpi) were kept to the end of the study as recovery control. Liver tissues were collected from HEV-infected rabbits at 5, 10 and 26 wpi for histopathological analysis. Nineteen rabbits (47.5%) developed chronic HEV infection with persistent viraemia and fecal HEV shedding for >6 months. Seroconversion to anti-HEV was observed in 84.2% (16/19) of the chronically infected rabbits. Serum levels of aminotransferase were persistently elevated in most of the rabbits. Characterizations of chronic HEV infection in immunocompetent settings could be recapitulated in rabbits, which can serve as a valuable tool for future studies on pathogenesis.

Cecolin9, a second-generation 9-valent HPV vaccine derived from the WHO-prequalified Cecolin, has received marketing authorisation in China in May 2025. The non-inferiority of type-specific immune responses between Cecolin9 and Gardasil9 has been previously established at month 7 in Chinese women aged 18-26 years (NCT04782895). This study aimed to compare the plateau antibody levels between the two vaccines three years post the first dose. This was a prospective extension study of a randomised, single-blind trial conducted in China (ClinicalTrials.gov, NCT06197802). All the participants included in the base study were invited to participate in this extension. Blood samples were collected at year 3 (median follow-up time of 34 months) for neutralising antibody detection, assessed by a triple-colour pseudovirion-based neutralisation assay. The primary outcome, geometric mean concentrations (GMCs), was analysed within three-dose recipients without major protocol violations, seronegative for the relevant type at baseline, and with available serum results at year 3. Non-inferiority of the GMC ratios (Cecolin9 vs Gardasil9) was determined as the lower bound of the two-sided 95% confidence interval (CI) in excess of 0.5. Of the 487 participants enrolled in the base study, 82.8% (403/487) completed the three-year follow-up visit. The mean age at the first vaccination was 22.2 years among the 200 Cecolin9 recipients and 22.1 years among the 203 Gardasil9 recipients, respectively. The GMC ratios (Cecolin9 vs Gardasil9) for all nine HPV types ranged from 0.78 (95% CI 0.64-0.95) to 1.91 (95% CI 1.54-2.37), with the lower bounds of 95% CIs spanning from 0.64 to 1.54. Furthermore, sustained seropositivity rates were similar between groups, ranging from 84.7% to 100.0% in the Cecolin9 cohort and 86.2% to 100.0% in the Gardasil9 cohort. Notably, both groups presented consistent antibody decay trends over the observation period. The Cecolin9 cohort demonstrated sustained non-inferior HPV type-specific plateau antibody levels compared to the Gardasil9 cohort, supporting Cecolin9's potential for enduring protection. National Key Research and Development Plan, the National Natural Science Foundation of China, Beijing Natural Science Foundation, Fundamental Research Funds for the Central Universities, the Fieldwork Funds for graduate students of Xiamen University, and Xiamen Innovax.

Background: The detection and accurate genotyping of human papillomavirus (HPV) infection is critical for preventing and effectively treating cervical cancer.Methods: A multiplex fluorescent polymerase chain reaction (PCR) coupled with a capillary electrophoresis method was developed for the simultaneous detection of the 16 most prevalent HPV genotypes. Twenty‐five pairs of primers were ultimately selected to ensure that both E and L regions of nine HPV genotypes, as well as the E regions of seven HPV genotypes could be accurately amplified.Results: This method enables the simultaneous detection and differentiation of 16 HPV genotypes in a single closed‐tube reaction, accurately distinguishing products with molecular weight differences >1 bp through capillary electrophoresis. This method demonstrated exceptional accuracy, specificity, and repeatability with a detection limit of 10 copies/μL for all 16 HPV genotypes. Furthermore, 152 cervical swab specimens were obtained to compare the disparities between this approach and Cobas 4800 HPV detection method. The concordance rate and κ value were 90.1% and 0.802, respectively, indicating a high level of agreement. The established detection method was successfully applied to cervical swab specimens for determining HPV genotypes across all levels of cervical lesions, HPV52, 56, 16, and 59 were found to be most prevalent with infection rates of 10.8%, 9.1%, 6.5%, and 6.2%, respectively.Conclusions: This study has successfully established a detection method capable of simultaneously identifying 16 HPV genotypes. This approach can be further applied to HPV vaccine research and surveillance, with the potential for broad applications.

Herpes simplex virus (HSV) is a highly prevalent neurotropic DNA virus that causes orolabial herpes, genital herpes, keratitis, neonatal infection, meningitis and encephalitis. HSV-1 and HSV-2 share epithelial entry, lytic replication, immune evasion, lifelong sensory-ganglion latency and periodic reactivation, yet they differ in typical transmission routes, anatomical recurrence and public-health burden. Rather than mechanically separating both viruses throughout, this review emphasizes shared HSV biology and highlights type-specific differences where they affect clinical interpretation or intervention design. We connect glycoprotein-mediated entry, receptor use, axonal transport, immune evasion and latency with mucocutaneous, ocular, neurologic, neonatal and genital disease. We then synthesize lessons from failed glycoprotein-D vaccine trials, multivalent and mRNA platforms, helicase–primase inhibitors, monoclonal antibodies, RNA-based approaches, genome editing and latency-directed strategies. A mechanism-guided HSV strategy should reduce acquisition, shedding and recurrence, prevent ocular, neurologic and neonatal complications, manage antiviral resistance and ultimately address latent infection.

Vaccination is highly effective in preventing human papillomavirus (HPV) infection, but traditional pseudovirion-based neutralization assays (PBNA) are technically demanding, labor-intensive, and costly, limiting their use in multivalent vaccine studies. We developed and validated an automated, high-throughput PBNA in a 384-well format that quantifies neutralizing antibodies against 15 HPV types using triple-color pseudotyped viruses. Non-interfering type triplets were defined from cross-neutralization assays of serum against pseudotyped viruses, enabling simultaneous detection of three fluorescence signals per well. The workflow integrates a cap-decapper, semi-automatic sample addition and dilution, and a microplate stacker with automated imaging to reduce hands-on time. The 384-well method showed strong concordance with the conventional 96-well PBNA while increasing daily sample throughput by approximately 6.7-fold, reducing assay duration (including ~4-fold faster imaging), and lowering reaction volume by ~5-fold. Analytical validation demonstrated acceptable specificity, accuracy, repeatability, linearity and robustness for high-throughput use. Serostatus cutoff values were established in an age-appropriate female population to support classification of positive versus negative sera. This platform provides a scalable tool for evaluating neutralizing antibodies after natural infections or vaccination and is well suited for large clinical trials and the development of next-generation and multivalent HPV vaccines.