Central memory T (Tcm) cells are a crucial subset in T cell development, playing an important role in long-term immune responses. Tcm cells exhibit strong proliferative capacity, long-term survival characteristics, and re-activation potential, enabling them to rapidly differentiate into effector T cells (Teff) upon antigen re-exposure, thus providing robust immune protection. The function of Tcm cells is regulated by various factors, including antigen exposure, cytokines, and metabolic conditions. A deeper understanding of their metabolic and epigenetic mechanisms under different pathological conditions will contribute to the development of more precise and effective immunotherapeutic strategies. This review elaborates on the origin and characteristics of Tcm cells, as well as their roles in antiviral responses, tumor immunity, and immunotherapy.
Humans ; Memory T Cells/cytology* ; Animals ; Immunologic Memory ; Neoplasms/therapy* ; Immunotherapy

The seamless phase Ⅱ/Ⅲ design integrates independent phase Ⅱ and phase Ⅲ clinical trials into a continuous, phased adaptive clinical trial design. Compared with traditional independent phase Ⅱ and phase Ⅲ clinical trials, the seamless design offers significant advantages in accelerating drug or vaccine development and improving clinical trial efficiency. Currently, the application of this design in anti-tumor drug research is becoming increasingly mature, and it is gradually expanding to clinical trials of vaccines, including the 9-valent human papillomavirus vaccine, sabin strain inactivated polio vaccine, and others. This paper aims to clarify the seamless phase Ⅱ/Ⅲ design concept and offer valuable insights into its implementation. It accomplishes this by presenting a clinical trial example featuring a phase Ⅱ/Ⅲ seamless design for a 9-valent human papillomavirus vaccine. The article delves into the specific considerations and potential challenges related to implementing the seamless design, aiming to provide valuable insights for optimizing vaccine clinical trials within our country.

Bacille Calmette-Guérin (BCG) vaccine is designed to provide protection against tuberculosis (TB). However, numerous epidemiological, clinical, and immunological studies have shown that BCG vaccination affects neonatal and infant mortality, which may be related to the reduction of TB-unrelated infections and diseases by BCG vaccine. We aimed to discuss the off-target effects of BCG vaccine on un-TB infections and diseases, as well as the potential mechanism and influencing factors. Literature was retrieved mainly from PubMed using medical subject headings "BCG, variations, and non-specific, heterologous or off-target". Studies have showed that BCG vaccination can prevent various heterologous infections, including respiratory tract infections, leprosy, and malaria, treat viral infections including human papillomavirus and herpes simplex virus infection as immunotherapy, and improve the immune responses as vaccine adjuvant. Besides, BCG vaccine can reduce the recurrence rate of non-muscle-invasive bladder cancer, and may provide protection against autoimmune diseases. These off-target effects of BCG vaccine are thought to be achieved by modulating heterologous lymphocyte responses or inducing trained immunity, which were found to be sex-differentiated and affected by the BCG vaccine strains, sequence or time of vaccination.

Objective To explore the causal relationship between social stress and tinnitus onset using a two-sample Mendelian randomization approach. Methods Genetic data pertaining to social stress and tinnitus were extracted from genome-wide association studies (GWAS) databases. Single nucleotide polymorphisms (SNP) that were independent and strongly correlated with social stress were selected as instrumental variables, with tinnitus serving as the outcome variable. Mendelian randomization analyses were performed using inverse-variance weighted (IVW) method, weighted median method, and Mendelian randomization-Egger regression. The intercept term from Mendelian randomization-Egger regression was utilized to assess horizontal pleiotropy, Cochran's Q statistic was employed to evaluate heterogeneity, and leave-one-out analysis was conducted for sensitivity assessment. Results The social stress dataset encompassed 459, 742 samples, while the tinnitus dataset comprised 117, 882 samples. A total of 10 SNPs tightly associated with social stress were identified as instrumental variables. The analysis results of random-effects inverse variance weighting (IVW), weighted median method, and Mendelian randomization-Egger regression were similar (OR=1.251, 1.274, 1.438), indicating that social stress was a risk factor for tinnitus, and there was a positive causal effect between them, with no heterogeneity or pleiotropy in the results. Conclusion There is a causal relationship between social stress and tinnitus onset, which may offer novel perspectives for the clinical prevention and treatment of tinnitus in the future.

The COVID-19 outbreak at the end of 2019 has accelerated the development and research for COVID-19 vaccines worldwide. Among the COVID-19 vaccines in clinical trials developed via different platforms, recombinant virus vector-based vaccines have shown excellent immunogenicity and efficacy. However, at the same time, there are serious issues such as vaccine safety and pre-existing antibodies against vectors. This article summarizes the design concept and development history of recombinant virus vector-based vaccines, and focuses on the progress in the clinical studies of vector-based COVID-19 vaccines as well as the challenges, in order to provide reference for the research of recombinant vector-based vaccines.
COVID-19/prevention & control* ; COVID-19 Vaccines ; Genetic Vectors ; Humans ; Vaccines, Synthetic ; Viral Vaccines

A large-scale vaccination of coronavirus disease-19 (COVID-19) in adults has been conducted for nearly a year, and there is a growing recognition that immunization for children is also essential. It has been months since emergency use of pediatric COVID-19 vaccine was approved, we reviewed the prevalence and transmission of COVID-19 in children. The prevalence of COVID-19 in children is reduced due to vaccination even in a Delta prevalent period, so an increase in the vaccination rate is needed in children. Although the precise role of children in the transmission requires more research to uncover, they likely played a significant role, according to the available literature. We also described four candidate COVID-19 vaccines for children on their safety and immunogenicity and the impact of severe acute respiratory syndrome coronavirus 2 variants on childhood vaccination. Safety issues on pediatric vaccines post-approval, like adverse events following immunization and adverse events of special interest require studies on long-term and effective regulatory mechanisms.

BACKGROUND: The new emerging avian influenza A H7N9 virus, causing severe human infection with a mortality rate of around 41%. This study aims to provide a novel treatment option for the prevention and control of H7N9. METHODS: H7 hemagglutinin (HA)-specific B cells were isolated from peripheral blood plasma cells of the patients previously infected by H7N9 in Jiangsu Province, China. The human monoclonal antibodies (mAbs) were generated by amplification and cloning of these HA-specific B cells. First, all human mAbs were screened for binding activity by enzyme-linked immunosorbent assay. Then, those mAbs, exhibiting potent affinity to recognize H7 HAs were further evaluated by hemagglutination-inhibiting (HAI) and microneutralization in vitro assays. Finally, the lead mAb candidate was selected and tested against the lethal challenge of the H7N9 virus using murine models. RESULTS: The mAb 6-137 was able to recognize a panel of H7 HAs with high affinity but not HA of other subtypes, including H1N1 and H3N2. The mAb 6-137 can efficiently inhibit the HA activity in the inactivated H7N9 virus and neutralize 100 tissue culture infectious dose 50 (TCID50) of H7N9 virus (influenza A/Nanjing/1/2013) in vitro, with neutralizing activity as low as 78 ng/mL. In addition, the mAb 6-137 protected the mice against the lethal challenge of H7N9 prophylactically and therapeutically. CONCLUSION The mAb 6-137 could be an effective antibody as a prophylactic or therapeutic biological treatment for the H7N9 exposure or infection.
Animals ; Antibodies, Monoclonal/therapeutic use* ; Antibodies, Neutralizing/therapeutic use* ; Antibodies, Viral ; Hemagglutinins ; Humans ; Influenza A Virus, H1N1 Subtype ; Influenza A Virus, H3N2 Subtype ; Influenza A Virus, H7N9 Subtype ; Influenza Vaccines ; Influenza in Birds ; Influenza, Human/prevention & control* ; Mice

COVID-19 ; Coronavirus Nucleocapsid Proteins ; Humans ; Nucleocapsid Proteins ; Phosphoproteins ; SARS-CoV-2

Avian influenza virus (AIV) is a kind of zoonotic virus which can cause acute respiratory infectious diseases. Since the report of the world's first human infection case of avian influenza A (H7N9) virus in China in 2013, close attention has been paid to the virus. AIV spreads widely around the world, and human infection with different types of AIV continues to occur, causing huge economic losses. At present, there are no specific treatment and drugs against the disease, and vaccination is considered as the most promising and effective method to control the human infection with AIV. So far, there are many kinds of veterinary and human vaccines for H7N9 AIV, among which four types of human H7N9 AIV vaccines have entered the clinical trial stage, including virus-like particles vaccine, attenuated live vaccine, inactivated vaccine and DNA vaccine, which have shown good safety and immunogenicity. However, the true efficacies of the AIV vaccines remain unknown because no human vaccines are currently available in the market. In addition, although the existing influenza vaccine has good safety and immunogenicity in the human population, there is no cross-antibody response to H7N9 AIV. This paper summarizes the research progress of AIV etiology and epidemiology, the occupational exposure population investigation, the infection prevention and control strategies, and H7N9 AIV vaccine and H7N9 AIV anthropogenic monoclonal antibody, and discuss the remained problems, challenges and future trends in the research of AVI to improve the understanding of the disease and the prevention and control of global spread of AIV.

When the coverage of the vaccinated people reaches a certain percentage of the population, the herd protection will protect the unvaccinated persons. However, the traditional clinical evaluation of vaccines performing individual randomized design fails to evaluate the herd protection of vaccines. Compared with the individual randomized design, the cluster-randomized design can determine the overall protection by the vaccine more comprehensively. It has become increasingly common to perform a cluster-randomized design in clinical trials of vaccines in Phase Ⅲ and Ⅳ clinical trials. However, little is known about the application of cluster randomized design in vaccine clinical trials in China. We, at this moment, do a review of the application of random cluster design in vaccine clinical trials and provide references for future research in China.