Safety and immunogenicity of a pichia pastoris-expressed bivalent human papillomavirus (types 16 and 18) L1 virus-like particle vaccine in healthy Chinese women aged 9-45 years: A randomized, double-blind, placebo-controlled phase 1 clinical trial.

BACKGROUND: We evaluated the safety and immunogenicity of high and low doses of a novel pichia pastoris-expressed bivalent (types 16 and 18) human papillomavirus (HPV) virus-like particle vaccine. METHODS: In this randomized, double-blind, placebo-controlled phase 1 trial, we enrolled 160 healthy females aged 9-45 years in Guangxi, China who were randomized (1:1:2) to receive either low (0.5 mL) or high (1.0 mL) dosages of bivalent HPV vaccine, or placebo (aluminum adjuvant) in a 0, 2, 6 months schedule. Adverse events and other significant conditions that occurred within 30 days after each vaccination were recorded throughout the trial. Sera were collected at days 0, 60, 180 and 210 to measure anti-HPV 16/18 neutralizing antibodies. RESULTS: A total of 160 participants received at least one dose of the HPV vaccine and 152 completed the three dose vaccination series. Reporting rates of adverse events in placebo, low dose (0.5 mL) and high dose (1.0 mL) groups were 47.5 %, 55.0 % and 55.0 %, respectively. No serious adverse events occurred during this trial. 100 % of the participants who received three doses of the HPV vaccine produced neutralizing antibodies against HPV 16/18 vaccine. For HPV 16 and HPV 18, the geometric mean titers (GMTs) were similar between the low dose group (GMTHPV 16 = 10816 [95 % CI: 7824-14953]), GMTHPV 18 = 3966 [95 % CI: 2693-5841]) and high dose group (GMT HPV 16 = 14482 [95 % CI: 10848-19333], GMT HPV 18 = 3428 [95 % CI: 2533-4639]). CONCLUSION: The pichia pastoris-expressed bivalent HPV vaccine was safe and immunogenic in Chinese females aged 9-45 years. The low dosage (0.5 mL) was selected for further immunogenicity and efficacy study.

Effectiveness of vero cell inactivated vaccine against severe acute respiratory infections (SARI) in Sibu, Malaysia: A retrospective test-negative design.

The effectiveness of the vero cell inactivated vaccine (CoronaVac®) against severe acute respiratory infection ( SARI) caused by SARS-CoV-2 in the real world was assessed. A matched test-negative case-control design was employed using the web-based national information system, as well as the hospitalization dataset in Sibu Hospital. Vaccine effectiveness was measured by conditional logistic regression with adjustment for gender, underlying comorbidity, smoking status, and education level. Between 15 March and 30 September 2021, 838 eligible SARI patients were identified from the hospitalization records. Vaccine effectiveness was 42.4% (95% confidence interval [CI]: -28.3 to 74.1) for partial vaccination (after receiving the first dose to 14 days after receiving the second dose), and 76.5% (95% CI: 45.6 to 89.8) for complete vaccination (at 15 days or more after receiving the second dose). This analysis indicated that two doses of CoronaVac® vaccine provided efficacious protection against SARI caused by SARS-CoV-2 in the short term. However, the duration of protection, and performance against new variants need to be studied continuously.

Relative vaccine effectiveness against Delta and Omicron COVID-19 after homologous inactivated vaccine boosting: a retrospective cohort study.

ObjectiveTwo COVID-19 outbreaks occurred in Henan province in early 2022-one was a Delta variant outbreak and the other was an Omicron variant outbreak. COVID-19 vaccines used at the time of the outbreak were inactivated, 91.8%; protein subunit, 7.5%; and adenovirus5-vectored, 0.7% vaccines. The outbreaks provided an opportunity to evaluate variant-specific breakthrough infection rates and relative protective effectiveness of homologous inactivated COVID-19 vaccine booster doses against symptomatic infection and pneumonia. DESIGN: Retrospective cohort study METHODS: We evaluated relative vaccine effectiveness (rVE) with a retrospective cohort study of close contacts of infected individuals using a time-dependent Cox regression model. Demographic and epidemiologic data were obtained from the local Centers for Disease Control and Prevention; clinical and laboratory data were obtained from COVID-19-designated hospitals. Vaccination histories were obtained from the national COVID-19 vaccination dataset. All data were linked by national identification number. RESULTS: Among 784 SARS-CoV-2 infections, 379 (48.3%) were caused by Delta and 405 (51.7%) were caused by Omicron, with breakthrough rates of 9.9% and 17.8%, respectively. Breakthrough rates among boosted individuals were 8.1% and 4.9%. Compared with subjects who received primary vaccination series ≥180 days before infection, Cox regression modelling showed that homologous inactivated booster vaccination was statistically significantly associated with protection from symptomatic infection caused by Omicron (rVE 59%; 95% CI 13% to 80%) and pneumonia caused by Delta (rVE 62%; 95% CI 34% to 77%) and Omicron (rVE 87%; 95% CI 3% to 98%). CONCLUSIONS: COVID-19 vaccination in China provided good protection against symptomatic COVID-19 and COVID-19 pneumonia caused by Delta and Omicron variants. Protection declined 6 months after primary series vaccination but was restored by homologous inactivated booster doses given 6 months after the primary series.

Burden and etiology of moderate and severe diarrhea in children less than 5 years of age living in north and south of China: Prospective, population-based surveillance.

BACKGROUND: Diarrhea remains the leading cause of childhood illness in China. Better understanding of burden and etiology of diarrheal diseases is important for development of effective prevention measures. METHODS: Population-based diarrhea surveillance was conducted in Sanjiang (southern China) year-round and Zhengding (northern China) in autumn/winter. Stool specimens were collected from children < 5 years of age experiencing diarrhea. The TaqMan Array Card (TAC), based on multiplex real-time PCR, was applied to detect multiple enteric microbial agents simultaneously. Results using these methods were compared to those derived from conventional PCR assays. RESULTS: During the study period, 6,380 children in Zhengding and 3,581 children in Sanjiang < 5 years of age participated. Three hundred and forty (31.2%) and 279 (22.9%) diarrhea episodes were identified as moderate-to-severe in the two counties, with incidence of 60.4 and 88.3 cases per 1,000 child-years in Zhengding and Sanjiang, respectively. The five most frequently detected bacterial and viral agents in Sanjiang were adenovirus, enterovirus, enteroaggregative Escherichia coli (EAEC), rotavirus, and sapovirus all the year round, while the most common viral agents in Zhengding were rotavirus, followed by astrovirus and adenovirus during the cool season. Compared to conventional PCR assay, the average incremental detection via the TAC method was twofold. CONCLUSION: Our study demonstrated high diversity and prevalence of multiple major bacterial and viral agents, including rotavirus and calicivirus, among children in China. Further studies are needed to define the public health significance of neglected but frequently detected pathogens such as EAEC, enterotoxigenic E. coli, Campylobacter, adenovirus, and enterovirus.

Building radiation-resistant model in triple-negative breast cancer to screen radioresistance-related molecular markers.

BACKGROUND: To build the triple-negative breast cancer (TNBC) radiation resistance model in vitro and vivo, and screen the molecular markers that related to radiation resistance. METHODS: We used X-ray to irradiate MDA-MB-231 cells repeatedly to build radioresistant cell (231-RR), then select one gemcitabine-resistance of MDA-MB-231 cell (231-GEM). We screen differentially expressed genes of these cell lines. Then, we would select 2 genes of them associated with DNA damage repair or cell cycle, and build RNAi lentivirus vector to knock down related gene. We also used X-rays repeatedly exposure TNBC tumor xenograft to build tumor with radioresistance properties, and then verify previously screening differentially expressed genes using IHC. Finally, we used The Cancer Genome Atlas (TCGA) database to validate the relationships between radioresistance related genes and the prognosis of breast cancer. RESULTS: We got 161 up-regulated genes and 156 down-regulated genes from three cell lines. Cellular results show the 231-cell with knock-down CDKN1A or SOD2 gene, its radiation sensitivity was significantly enhanced. We successfully got the TNBC xenograft tumor with radioresistance properties. Immunohistochemical results show that the radioresistance of tumor tissue with higher p21 (CDKN1A encoding protein) and SOD2 expression (P<0.01). The prognosis of patients with low SOD2 expression is better than that of high expression, but have no statistical significance (P=0.119); patients with low CDKN1A expression is significantly better than high expression (P=0.000). Multivariate cox analysis manifest that CDKN1A gene expression level is an independent prognostic factor in breast cancer patient (P=0.008). CONCLUSIONS: Construction of radiation resistance cell and xenograft tumor with radio-resistant properties model for radiation biology research is feasible. High SOD2 and CDKN1A is associated with the poor prognosis in breast cancer patients. These two genes could be used as a predicted makers of breast cancer radiation sensitivity.

Burden of viral gastroenteritis in children living in rural China: Population-based surveillance.

BACKGROUND: Despite the considerable disease burden caused by the disease, rotavirus vaccine has not been introduced into routine national immunization schedule, and norovirus vaccines are being developed without a comprehensive understanding of gastroenteritis epidemiology. To bridge this knowledge gap, we investigated the disease burden of viral gastroenteritis in rural China. METHODS: Between October 2011 and December 2013, population-based surveillance was conducted in Zhengding and Sanjiang counties in China. Stool samples were collected from children <5 years of age with diarrhea. All specimens were tested for rotaviruses, noroviruses, sapoviruses, enteric adenoviruses, and astroviruses. RESULTS: The most common pathogen causing diarrhea was rotavirus (54.7 vs 45.6 cases/1,000 children/year in Zhengding and Sanjiang, respectively), followed by norovirus (28.4 vs 19.3 cases/1,000 children/year in Zhengding and Sanjiang, respectively). The highest incidence of these viruses was observed in children 6-18 months of age. Among the 5 viral pathogens, rotaviruses caused the most severe illness, followed by noroviruses. CONCLUSION: Rotavirus and norovirus are the 2 most important viral pathogens causing childhood diarrhea in both northern and southern China; they should be the major targets for viral gastroenteritis prevention strategies among children in China.

From therapeutic antibodies to immune complex vaccines.

In recent years, therapeutic monoclonal antibodies have made impressive progress, providing great benefit by successfully treating malignant and chronic inflammatory diseases. Monoclonal antibodies with broadly neutralizing effects against specific antigens, or that target specific immune regulators, manifest therapeutic effects via their Fab fragment specificities. Subsequently therapeutic efficacy is mediated mostly by interactions of the Fc fragments of the antibodies with their receptors (FcR) displayed on cells of the immune system. These interactions can trigger a series of immunoregulatory responses, involving both innate and adaptive immune systems and including cross-presentation of antigens, activation of CD8 + T cells and CD4 + T cells, phagocytosis, complement-mediated antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). The nature of the triggered effector functions of the antibodies is markedly affected by the glycosylation patterns of the Fc fragments. These can cause differences in the conformation of the heavy chains of antibodies, with resultant changes in antibody binding affinity and activation of the complement system. Studies of the Fc glycosylation profiles together with the associated Fc effector functions and FcR/CR interactions promoted interest and progress in engineering therapeutic antibodies. Furthermore, because antigen-antibody immune complexes (ICs) have shown similar actions, in addition to certain novel immunoregulatory mechanisms that also reshape immune responses, the properties of ICs are being explored in new approaches for prevention and therapy of diseases. In this review, both basic studies and experimental/clinical applications of ICs leading to the development of preventive and therapeutic vaccines are presented.

Prevalence and distribution of human papillomavirus genotypes in Chinese women between 1991 and 2016: A systematic review.

BACKGROUND: Human papillomavirus (HPV) associated cervical cancer is one of the most common cancers and ranked as the eighth most common killer for Chinese women. A dozen of HPV vaccines are being developed in China without a solid China-specific distribution of carcinogenic HPV types, thus, we performed this systematic review to explore the China-specific spectrum of high-risk types causing cancer. METHODS: Studies on HPV infection among Chinese women were searched. All retrieved articles were screened and reviewed by a standardized algorithm. Distribution of carcinogenic HPV types and age-specific prevalence were analyzed using random-effects model. RESULTS: A total of 303 articles were included in the final analysis. The top 10 common HPV types detected in ICC patients, in descending order of frequency, were HPV 16 (62.5%), 18 (12.4%), 58 (8.6%), 52 (5.7%), 33 (4.6%), 31 (3.5%), 55 (2.4%), 68 (2.4%), 53 (2.2%) and 45 (2.0%) respectively. Similar spectrum was found in women with precancer. The prevalence of HPV infection peaked between 20 and 24 years with a rate of 24.3%, thereafter declined substantially and stabilized at middle-ages. Compared to women living in the developed provinces, the second peak was observed among women aged 45-55 years in less developed regions. CONCLUSION: In general, the spectrum of HPV types in women with precancer/cancer and the pattern of age-specific prevalence were consistent with that of elsewhere worldwide. However, some distinguished characteristics could also be concluded, and these imprinting should be considered and integrated when developing vaccines and strategy for disease control in China.

Analysis of immunological mechanisms exerted by HBsAg-HBIG therapeutic vaccine combined with Adefovir in chronic hepatitis B patients.

An HBsAg-HBIG therapeutic vaccine (Yeast-derived Immune Complexes, YIC) for chronic hepatitis B (CHB) patients has undergone a series of clinical trials. The HBeAg sero-conversion rate of YIC varied from 21.9% to 14% depending on the immunization protocols from 6 to 12 injections. To analyze the immunological mechanisms exerted by 6 injections of YIC, 44 CHB patients were separately immunized with YIC, alum as adjuvant control or normal saline as blank control, with add on of antiviral drug Adefovir in all groups. Kinetic increase in Th1 and Th2 cells CD4+ T cell sub-populations with association in decrease in Treg cells and increase of Tc1 and Tc17 cells in CD8+ T cells were observed in YIC immunized group. No such changes were found in the other groups. By multifunctional analysis of cytokine profiles, significant increase of IL-2 levels was observed, both in CD4+ and CD8+ T cells in the YIC immunized group, accompanied by increase in IFN-gamma and decrease of inhibitory factors (IL-10, TGF-ß and Foxp3) in CD4+ T cells. In the alum immunized group, slight increase of IL-10, TGF-ß and Foxp3 in CD4+ T cells was found after the second injection, but decreased after more injections, suggesting that alum induced early inflammatory responses to a certain extent. Similar patterns of responses of IL-17A and TNF-α in CD8+T cells were shown between YIC and the saline group. Results indicate that add on of Adefovir, did not affect host specific immune responses.

Responses to multiple injections with alum alone compared to injections with alum adsorbed to proteins in mice.

New effects and mechanisms of alum on innate immunity have emerged in recent years. A number of cellular and molecular mechanisms induced by aluminum adjuvant have been reported, while the role of NALP3 and inflammasome in the cellular pathway induced by alum is still controversial. The effect of injection of alum alone without vaccine antigen into human has not been reported so far. Recently, in a phase IIIa double-blinded placebo controlled clinical trial testing the therapeutic HBsAg-anti-HBs vaccine formulated with alum against chronic viral hepatitis B patients, the placebo group receiving alum only showed substantial therapeutic effects. To explore possible underlying therapeutic mechanisms, mice were treated either with multiple injections of alum alone or with alum adsorbed to proteins (HBsAg-anti-HBs). After 4 injections Gr1(+)/CD11b(+) cells in the spleen were increased in both alum alone and alum adsorbed in proteins groups. Increased Gr1(+)/CD11b(+) cells in spleens remained consistently high in the alum alone treated group, while Gr1(+)/CD11b(+)cells decreased in the alum adsorbed to proteins group after 6 injections. Both treatments triggered increased levels of TNF-alpha measured in the plasma, but only the alum alone treated mice showed increased levels of IL-10. Histology of the liver tissues revealed a higher number of spotty necrotic foci in the alum alone immunized group. Taken together, potent inflammatory responses were induced in the alum alone immunized mice, which suggests that the substantial therapeutic effects observed in chronic hepatitis B patients immunized with alum alone might be attributed to inflammatory responses.

Immunization with HBsAg-Fc fusion protein induces a predominant production of Th1 cytokines and reduces HBsAg level in transgenic mice.

BACKGROUND: The Fc receptor associated pathway might improve the immune responses against hepatitis B virus (HBV) as previously described by us. In addition, the Flt3 ligand (FL) has been reported to potentiate antigen presenting cells in vivo and may act as a potential adjuvant to boost antigen-specific immune responses. In this study, the immune efficacies of a set of fusion proteins of HBsAg and Fc and/or FL were evaluated in HBsAg transgenic mice. METHODS: The fusion proteins composed of HBsAg and the Fc domain of murine IgG1 (HBsAg-Fc) and/or the Flt3 ligand, and yeast-derived recombinant HBsAg were used as immunogen to immunize HBsAg transgenic mice, respectively. Serum and liver HBsAg levels, serum anti-HBsAg and cytokine profile, and the activities of alanine aminotransferase (ALT)/AST were investigated after immunization. RESULTS: After six injections, the most pronounced decrease in serum and liver HBsAg levels was observed in the HBsAg-Fc immunized group. In addition, serum Th1 cytokines and ALT/AST activities were highest in this group, indicating an effective induction of a favorable cellular immune response. Interestingly, the fusion protein containing HBsAg-Fc and the Flt3 ligand stimulated an alternative Th1-type immune response featured with high level productions of tumor necrosis factor α (TNF-α) and monocyte chemoabstractant protein 1 (MCP-1), causing a more severe cytotoxicity in hepatocytes while showed less effective in reducing serum HBsAg level. CONCLUSION: HBsAg-Fc is effective in eliciting both the humoral and cellular immune responses against HBsAg in HBsAg transgenic mice, which makes it a potential immunogen for the immunotherapy of chronic hepatitis B.

[Involvement of epidermal growth factor receptor signaling pathway in tamoxifen resistance of MCF-7 cells].

BACKGROUND & OBJECTIVE: Tamoxifen (TAM) is an important endocrine therapeutic drug used in combined treatment for breast cancer. However the drug resistant effect of TAM has become a major concern in clinical use. Epidermal growth factor receptor (EGFR) is expressed in many tumors and the expression of EGFR in breast cancer tissues is associated with poor prognosis. This study was to investigate EGFR signaling pathway in the drug resistant effect of TAM in breast cancer cells. METHODS: An estrogen receptor (ER) positive breast cancer cell line, MCF-7 was incubated with TAM (10(-7) mol/L) for up to 6 months to produce drug resistant cells. mRNA and protein expression of EGFR signaling pathway related genes and ER gene was analyzed by fluorescent quantitation reverse transcription-polymerase chain reaction (fqRT-PCR) and Western blot. AG1478, an EGFR inhibitor, was also used to study the drug resistant effect of TAM. RESULTS: The proliferation of MCF-7 cells was inhibited in the early stage after TAM treatment. However the inhibitory effect vanished after continuous 6-month treatment and the cell proliferation rate returned back to normal. The tolerance of MCF-7 cells to TAM was confirmed by cell growth inhibitory test. In TAM resistant MCF-7 cells, the expression of EGFR mRNA was increased by 4.5 times and the protein expression of EGFR, phosphorylation-extracellular signal-regulated kinase (p-ERK1/2) was also increased dramatically (P<0.05). While ER protein expression remained unchanged. Moreover the drug resistant cells were identified more sensitive to AG1478. CONCLUSION: In endocrine therapy, TAM resistant breast cancer cells are likely to be generated by the activation of EGFR signaling pathway after long-term TAM treatment, and EGFR inhibitors might increase the therapeutic effects in breast cancer treatment.