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.

Objective:To analyze the effects of SARS-CoV-2 infection and vaccination on virus mutation.Methods:The whole genome sequencing sequences of 2 659 local SARS-CoV-2 specimens from Jiangsu Province in 2023 were selected for analysis, and relevant information such as demographic and clinical characteristics were collected, and the effects of infection and vaccination on the genome-wide mutation rate and S gene′s selective pressure of the virus were analyzed by univariate and multivariate linear regression models.Results:The average age of these infected patients was 55.0 (31.0, 74.0) years, 1 150 cases (43.2%) in the age group of ≥60 years, 1 367 cases (51.4%) were males, 2 044 cases (76.9%) had a history of COVID-19 vaccination, and 1 629 cases (61.3%) had the first-time infection. The clinical symptoms of the infected patients were mainly mild, with a total of 2434 cases (91.5%), and 29 cases (1.1%) with severe symptoms or more. The average substitution rate of SARS-CoV-2 was 9.69 (9.38, 9.98)×10 -4 subs/site/year, and the dN/dS value of the S gene was 6.08 (5.56, 8.66), which was significantly greater than that of 1 ( P<0.001), indicating positive selection. The result of univariate and multivariate linear regression model analysis showed that the SARS-CoV-2 substitution rate was higher in those with vaccination history and reinfection, aged 20-30 years, ≥60 years, and the SARS-CoV-2 substitution rate was lower in males with moderate clinical symptoms and severe disease and above. Those with a history of vaccination and reinfection, aged 50-60 years old, ≥60 years old have smaller S gene dN/dS. Conclusions:Under the immune pressure exerted by vaccination and infection, the genome-wide mutation of SARS-COV-2 accelerated, but the non-synonymous mutation rate of the S gene decreased. The mechanism causing these phenomena needs further study.

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.

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

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.

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.

Hepatitis B virus (HBV) can cause a variety of hepatitis B-related diseases in infected people, and there is no specific drug for treatment. China, with a large population base, is the country with the heaviest burden of HBV infection in the world. Therefore, hepatitis B vaccination is particularly important in the prevention and control of this disease. However, some vaccinees did not produce effective protective immune response after vaccination according to the recommended hepatitis B vaccine immunization schedule. The purpose of this review is to analyze the influential factors of non/low immune response after hepatitis B vaccination from the aspects of organism and vaccine, and explore the mechanism of non/low immune response, so as to provide scientific basis for the prevention and treatment of hepatitis B in China.

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.

Objective:To establish a rapid method for detecting the activity of 2019-nCoV2.Methods:The reverse transcription-quantitative polymerase chain reaction (RT-qPCR) detection system was screened after propidium monoazide (PMA) treatment and exposure to heat-inactivated 2019-nCoV samples, and the PMA pretreatment conditions were optimized to establish the 2019-nCoV PMA-RT-qPCR detection method . The established method was used to detect virus inactivated by different temperatures and chlorine-containing disinfectant, to evaluate its effect in detecting virus activity.Results:For the PMA-RT-qPCR assay, 200 μmol/L of PMA, 10 min of incubation time, 15 min of exposure time, and the CDC ORF1ab detection system were selected; there was no significant difference in the result of PMA-RT-qPCR and direct RT-qPCR for the active virus; the Ct values of PMA-RT-qPCR for virus inactivated by 95 ℃ and chlorine-containing disinfectant were higher than that of control groups at different dilutions; only partial dilutions of 70 ℃ and 56 ℃ heat-inactivated virus had higher Ct values than control groups. Conclusions:The established PMA-RT-qPCR for 2019-nCoV activity detection method has a good detection effect on the virus inactivated by 95 ℃ heat and chlorine disinfectant, and provides an auxiliary means for judging the infectivity of the virus in the sample.