A mosaic-type trimeric RBD-based COVID-19 vaccine candidate induces potent neutralization against Omicron and other SARS-CoV-2 variants.

Large-scale populations in the world have been vaccinated with COVID-19 vaccines, however, breakthrough infections of SARS-CoV-2 are still growing rapidly due to the emergence of immune-evasive variants, especially Omicron. It is urgent to develop effective broad-spectrum vaccines to better control the pandemic of these variants. Here, we present a mosaic-type trimeric form of spike receptor-binding domain (mos-tri-RBD) as a broad-spectrum vaccine candidate, which carries the key mutations from Omicron and other circulating variants. Tests in rats showed that the designed mos-tri-RBD, whether used alone or as a booster shot, elicited potent cross-neutralizing antibodies against not only Omicron but also other immune-evasive variants. Neutralizing antibody ID50 titers induced by mos-tri-RBD were substantially higher than those elicited by homo-tri-RBD (containing homologous RBDs from prototype strain) or the BIBP inactivated COVID-19 vaccine (BBIBP-CorV). Our study indicates that mos-tri-RBD is highly immunogenic, which may serve as a broad-spectrum vaccine candidate in combating SARS-CoV-2 variants including Omicron.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic continues to pose a serious threat to public health and has so far resulted in over six million deaths worldwide. Mass vaccination programs have reduced the risk of serious illness and death in many people, but the virus continues to persist and circulate in communities across the globe. Furthermore, the current vaccines may be less effective against the new variants of the virus, such as Omicron and Delta, which are continually emerging and evolving. Therefore, it is urgent to develop effective vaccines that can provide broad protection against existing and future forms of SARS-CoV-2. There are several different types of SARS-CoV-2 vaccine, but they all work in a similar way. They contain molecules that induce immune responses in individuals to help the body recognize and more effectively fight SARS-CoV-2 if they happen to encounter it in the future. These immune responses may be so specific that new variants of a virus may not be recognized by them. Therefore, a commonly used strategy for producing vaccines with broad protection is to make multiple vaccines that each targets different variants and then mix them together before administering to patients. Here, Zhang et al. took a different approach by designing a new vaccine candidate against SARS-CoV2 that contained three different versions of part of a SARS-CoV2 protein ­ the so-called spike protein ­ all linked together as one molecule. The different versions of the spike protein fragment were designed to include key features of the fragments found in Omicron and several other SARS-CoV-2 variants. The experiments found that this candidate vaccine elicited a much higher immune response against Omicron and other SARS-CoV-2 variants in rats than an existing SARS-CoV-2 vaccine. It was also effective as a booster shot after a first vaccination with the existing SARS-CoV-2 vaccine. These findings demonstrate that the molecule developed by Zhang et al. induces potent and broad immune responses against different variants of SARS-CoV-2 including Omicron in rats. The next steps following on from this work are to evaluate the safety and immunogenicity of this vaccine candidate in clinical trials. In the future, it may be possible to use a similar approach to develop new broad-spectrum vaccines against other viruses.

Design of a mutation-integrated trimeric RBD with broad protection against SARS-CoV-2.

The continuous emergence of SARS-CoV-2 variants highlights the need of developing vaccines with broad protection. Here, according to the immune-escape capability and evolutionary convergence, the representative SARS-CoV-2 strains carrying the hotspot mutations were selected. Then, guided by structural and computational analyses, we present a mutation-integrated trimeric form of spike receptor-binding domain (mutI-tri-RBD) as a broadly protective vaccine candidate, which combined heterologous RBDs from different representative strains into a hybrid immunogen and integrated immune-escape hotspots into a single antigen. When compared with a homo-tri-RBD vaccine candidate in the stage of phase II trial, of which all three RBDs are derived from the SARS-CoV-2 prototype strain, mutI-tri-RBD induced significantly higher neutralizing antibody titers against the Delta and Beta variants, and maintained a similar immune response against the prototype strain. Pseudo-virus neutralization assay demonstrated that mutI-tri-RBD also induced broadly strong neutralizing activities against all tested 23 SARS-CoV-2 variants. The in vivo protective capability of mutI-tri-RBD was further validated in hACE2-transgenic mice challenged by the live virus, and the results showed that mutI-tri-RBD provided potent protection not only against the SARS-CoV-2 prototype strain but also against the Delta and Beta variants.

Identification and semisynthesis of (-)-anisomelic acid as oral agent against SARS-CoV-2 in mice.

(-)-Anisomelic acid, isolated from Anisomeles indica (L.) Kuntze (Labiatae) leaves, is a macrocyclic cembranolide with a trans-fused α-methylene-γ-lactone motif. Anisomelic acid effectively inhibits SARS-CoV-2 replication and viral-induced cytopathic effects with an EC50 of 1.1 and 4.3 µM, respectively. Challenge studies of SARS-CoV-2-infected K18-hACE2 mice showed that oral administration of anisomelic acid and subcutaneous dosing of remdesivir can both reduce the viral titers in the lung tissue at the same level. To facilitate drug discovery, we used a semisynthetic approach to shorten the project timelines. The enantioselective semisynthesis of anisomelic acid from the naturally enriched and commercially available starting material (+)-costunolide was achieved in five steps with a 27% overall yield. The developed chemistry provides opportunities for developing anisomelic-acid-based novel ligands for selectively targeting proteins involved in viral infections.

Recombinant SARS-CoV-2 RBD with a built in T helper epitope induces strong neutralization antibody response.

Without approved vaccines and specific treatments, COVID-19 is spreading around the world with above 26 million cases and approximately 864 thousand deaths until now. An efficacious and affordable vaccine is urgently needed. The Val308 - Gly548 of spike protein of SARS-CoV-2 linked with Gln830 - Glu843 of Tetanus toxoid (TT peptide) (designated as S1-4) and without TT peptide (designated as S1-5) were expressed and renatured. The antigenicity and immunogenicity of S1-4 were evaluated by Western Blotting (WB) in vitro and immune responses in mice, respectively. The protective efficiency was measured preliminarily by microneutralization assay (MN50). The soluble S1-4 and S1-5 protein was prepared to high homogeneity and purity. Adjuvanted with Alum, S1-4 protein stimulated a strong antibody response in immunized mice and caused a major Th2-type cellular immunity supplemented with Th1-type immunity. Furthermore, the immunized sera could protect the Vero E6 cells from SARS-CoV-2 infection with neutralizing antibody titer 256. Recombinant SARS-CoV-2 RBD with a built in T helper epitope could stimulate both strong humoral immunity supplemented with cellular immunity in mice, demonstrating that it could be a promising subunit vaccine candidate.

The biological characteristics of SARS-CoV-2 spike protein Pro330-Leu650.

SARS-CoV-2 is the cause of the worldwide outbreak of COVID-19 that has been characterized as a pandemic by the WHO. Since the first report of COVID-19 on December 31, 2019, 179,111 cases were confirmed in 160 countries/regions with 7426 deaths as of March 17, 2020. However, there have been no vaccines approved in the world to date. In this study, we analyzed the biological characteristics of the SARS-CoV-2 Spike protein, Pro330-Leu650 (SARS-CoV-2-SPL), using biostatistical methods. SARS-CoV-2-SPL possesses a receptor-binding region (RBD) and important B (Ser438-Gln506, Thr553-Glu583, Gly404-Aps427, Thr345-Ala352, and Lys529-Lys535) and T (9 CD4 and 11 CD8 T cell antigenic determinants) cell epitopes. High homology in this region between SARS-CoV-2 and SARS-CoV amounted to 87.7%, after taking the biological similarity of the amino acids into account and eliminating the receptor-binding motif (RBM). The overall topology indicated that the complete structure of SARS-CoV-2-SPL was with RBM as the head, and RBD as the trunk and the tail region. SARS-CoV-2-SPL was found to have the potential to elicit effective B and T cell responses. Our findings may provide meaningful guidance for SARS-CoV-2 vaccine design.

Next-generation Sequencing Study of Pathogens in Serum from Patients with Febrile Jaundice in Sierra Leone.

OBJECTIVE: People in Western Africa suffer greatly from febrile jaundice, which is caused by a variety of pathogens. However, yellow fever virus (YFV) is the only pathogen under surveillance in Sierra Leone owing to the undeveloped medical and public health system there. Most of the results of YFV identification are negative. Elucidation of the pathogen spectrum is required to reduce the prevalence of febrile jaundice. METHODS: In the present study, we used Ion Torrent semiconductor sequencing to profile the pathogen spectrum in archived YFV-negative sera from 96 patients in Sierra Leone who presented with unexplained febrile jaundice. RESULTS: The most frequently identified sequencing reads belonged to the following pathogens: cytomegalovirus (89.58%), Epstein-Barr virus (55.21%), hepatitis C virus (34.38%), rhinovirus (28.13%), hepatitis A virus (20.83%), coxsackievirus (10.42%), Ebola virus (8.33%), hepatitis E virus (8.33%), lyssavirus (4.17%), leptospirosis (4.17%), chikungunya virus (2.08%), Crimean-Congo hemorrhagic fever virus (1.04%), and hepatitis B virus (1.04%). CONCLUSION: The distribution of sequencing reads suggests a broader spectrum of pathogens for consideration in clinical diagnostics and epidemiological surveillance in Sierra Leone.

HIV prevalence in suspected Ebola cases during the 2014-2016 Ebola epidemic in Sierra Leone.

BACKGROUND: The 2014-2016 Ebola virus epidemic in West Africa was the largest outbreak of Ebola virus disease (EVD) in history. Clarifying the influence of other prevalent diseases such as human immunodeficiency virus infection and acquired immune deficiency syndrome (HIV/AIDS) will help improve treatment and supportive care of patients with EVD. CASE PRESENTATION: We examined HIV and hepatitis C virus (HCV) antibody prevalence among suspected EVD cases from the Sierra Leone-China Friendship Biological Safety Laboratory during the epidemic in Sierra Leone. HIV and HCV antibodies were tested in 678 EVD-negative samples by enzyme-linked immunosorbent assay. A high HIV prevalence (17.6%) and low HCV prevalence (0.22%) were observed among the suspected cases. Notably, we found decreased HIV positive rates among the suspected cases over the course of the epidemic. This suggests a potentially beneficial effect of an improved public health system after assistance from the World Health Organization and other international aid organizations. CONCLUSIONS: This EVD epidemic had a considerable impact on the public health system and influenced the prevalence of HIV found among suspected cases in Sierra Leone, but also provided an opportunity to establish a better surveillance network for infectious diseases.

Development of an Internally Controlled Reverse Transcription Recombinase-aided Amplification Assay for the Rapid and Visual Detection of West Nile Virus.

West Nile virus (WNV) causes West Nile fever and West Nile encephalitis. Because infection by WNV creates serious public health problems, its simple, rapid, and visual detection is very important in clinical practice, especially in resource-limited laboratories. We have developed a rapid, specific, and highly sensitive internally controlled reverse transcription recombinase-aided amplification (RTRAA) assay to detect WNV, using both real-time fluorescence and the lateral flow dipstick (LFD) at 39.0 °C for 30 min. The analytical sensitivity of the RT-RAA assay was 10 plasmid copies and 1.6 pfu per reaction with real-time fluorescence, and 1,000 plasmid copies per reaction with the LFD. No crossreaction with other control viruses was observed. Compared with the RT-qPCR assay, the RT-RAA assay demonstrated 100% sensitivity and 100% specificity for WNV.

Establishment of a Chinese street rabies virus library and its application for detecting neutralizing activity.

BACKGROUND: The injection of rabies immune globulin (RIG) is of the utmost importance in the management of category III exposures to rabies-suspect animals. Because of the high cost and limited availability of existing RIG, one possible replacement for RIG is monoclonal antibodies (MAbs) against the rabies virus (RABV). Consequently, it is necessary to determine the neutralizing activity of the MAbs against rabies viruses, especially street rabies virus. However, the method to detect the neutralizing activity of MAbs against street rabies virus remains undefined. METHODS: To establish a method for detecting the neutralizing activity of MAbs against street rabies virus, we constructed a library consisting of 12 strains of street RABV from 11 provinces in China. Using this street RABV library and the Reed-Muench formula, we established a method for detecting the neutralizing titer of the MAbs. The reliability and repeatability of the method were evaluated by repeatedly measuring the neutralizing activity of a MAb and a post vaccination serum. RESULTS: A total of 12 strains of street RABV were chosen for inclusion in the street RABV library, which covered six Chinese lineages (China I-China VI) and grew to high titers in N2A cells (> 105 FFD50/ml). On the basis of the library, we constructed the method to detect the neutralizing activity of the MAbs. The results of repeatedly measuring the MAbs and positive serum showed excellent reliability and repeatability of the method established in this study. CONCLUSIONS: This study established a street RABV library reflecting the epidemiological features of Chinese rabies viruses, which provides a platform for detecting the neutralizing activity of MAbs against rabies viruses circulating in China.

Rabies virus transmission via solid organs or tissue allotransplantation.

BACKGROUND: Rabies, for which the mortality rate is almost 100%, is a zoonotic viral disease that can be transmitted via solid organs or tissue allotransplantation. Dozens of deaths from rabies via solid organs or tissues allotransplantation (ROTA) have been documented during the last decades. In 2015 and 2016, two cases of rabies virus transmission via solid organs or tissue allotransplantation were reported in China, which further underscore the risk and importance of this special type of rabies for organ transplant recipients. MAIN TEXT: From 1978 to 2017, at least 13 cases of ROTA, causing dozens of deaths, have been reported worldwide, whether in the high-risk or low-risk countries of rabies. The reported incubation period of ROTA ranges from 11 days to more than 17 months, while the historical incubation period of rabies is generally considered to range from ~ 1 week to several years. The pathogenesis of ROTA is not clear, but the use of post-exposure prophylaxis (PEP) can play a protective role in the transplant recipients. We also summarize reports about ROTA in China, combined with the actual situation regarding work on rabies surveillance and elimination, and suggest countermeasures for the prevention and control of ROTA in the future. CONCLUSIONS: Understanding the significance of ROTA, screening the suspected organs, assessing the risk and protecting the related population will be effective way to prevent and control further occurrence of ROTA.

Viral Contamination Source in Clinical Microbiology Laboratory.

To understand the potential causes of laboratory-acquired infections and to provide possible solutions that would protect laboratory personnel, samples from a viral laboratory were screened to determine the main sources of contamination with six subtypes of Rhinovirus. Rhinovirus contamination was found in the gloves, cuffs of protective wear, inner surface of biological safety cabinet (BSC) windows, and trash handles. Remarkably, high contamination was found on the inner walls of the centrifuge and the inner surface of centrifuge tube casing in the rotor. Spilling infectious medium on the surface of centrifuge tubes was found to contribute to contamination of centrifuge surfaces. Exposure to sodium hypochlorite containing no less than 0.2 g/L available chlorine decontaminated the surface of the centrifuge tubes from Rhinovirus after 2 min.

Good laboratory practices guarantee biosafety in the Sierra Leone-China friendship biosafety laboratory.

BACKGROUND: The outbreak of Ebola virus disease (EVD) in West Africa between 2014 and 2015 was the largest EDV epidemic since the identification of Ebola virus (EBOV) in 1976, and the countries most strongly affected were Sierra Leone, Guinea, and Liberia. FINDINGS: The Sierra Leone-China Friendship Biological Safety Laboratory (SLE-CHN Biosafety Lab), a fixed Biosafety Level 3 laboratory in the capital city of Sierra Leone, was established by the Chinese government and has been active in EBOV detection since 11 March 2015. Complete management and program documents were created for the SLE-CHN Biosafety Lab, and it was divided into four zones (the green, yellow, brown, and red zones) based on the risk assessment. Different types of safe and appropriate personnel protection equipment (PPE) are used in different zones of the laboratory, and it fully meets the Biosafety Level 3 laboratory standards of the World Health Organization. CONCLUSION: Good preparedness, comprehensive risk assessment and operation documents, appropriate PPE, effective monitoring and intensive training, together with well-designed and reasonable laboratory sectioning are essential for guaranteeing biosafety.

Serological Study of An Imported Case of Middle East Respiratory Syndrome and His Close Contacts in China, 2015.

The first imported Middle East respiratory syndrome (MERS) case in China was identified in May 2015. We determined the kinetics of antibody (IgG and IgM) and neutralizing antibodies against MERS-coronavirus (MERS-CoV) in this case before discharge. Moreover, no seroconversion was found among 53 close contacts by anti-MERS IgG antibody enzyme-linked immunosorbent assay (ELISA) of paired serum samples. These findings suggest that neither community nor nosocomial transmission of MERS-CoV occurred in China.

[Analysis on status and characteristics of laboratory-acquired vaccinia virus infections cases].

OBJECTIVE: By analyzing the status and characteristics of vaccinia virus laboratory-acquired infections in the bibliographical information, this paper provides relevant recommendations and measures for prevention and control of vaccinia virus laboratory-acquired infections in China. METHODS: Choosing PubMed, Embase, Biosis and SCIE, SSCI, CPCI-S as well as CPCI-SSH covered by Web of Science as the data source, indexing the bibliography of vaccinia virus laboratory-acquired infections, this paper analyzes the information on whether to vaccinate, the occurrence time of symptoms, diseasedparts, symptom characteristics and the disease-causing reasons. RESULTS: The outcome shows that 52. 9% of the cases never get vaccinated, 82.4% engaged in vaccinia virus related researches never get vaccinated in 10 years, 52. 9% get infected by the accidental needlestick in hands during the process of handling animal experiments, 70. 6% of infections occur in the hands and having symptoms after being exposed with an average of 5. 1 days. CONCLUSION: Although it is still controversial that whether or not to be vaccinated before carrying out vaccinia virus related works, it should be important aspects of prevention and control of vaccinia virus laboratory-acquired infections with the strict compliance with the operating requirements of the biosafety, by strengthening personal protection and timely taking emergency measures when unforeseen circumstances occur, as well as providing the research background information to doctors.

Contamination of live virus during tissue homogenizing by ultrasonic processor and tissue disperser.

OBJECTIVE: To quantitatively evaluate the contamination area and risk of a live pathogen during tissue homogenization by either ultrasonic processor or tissue disperser. METHODS: A recombinant Herpes Simplex Virus (rHSV) containing GFP gene was used as the index virus, and fresh liver tissue from healthy mice was used as simulated specimen. After 10% liver homogenate was mixed with rHSV (100 TCID50/0.1 mL) in a 5 mL tube, the stability of rHSV in liver homogenate and influences of an ultrasonic processor and a tissue disperser on viral infectivity were determined by GFP expressions in cell cultures. The contaminating areas of live viruses during homogenization were evaluated by a cell culture-based sedimentary. The contamination radii were counted by measurement of the distance between the operator and the farthest GFP positive well. RESULTS: The infectivity of rHSV in 10% liver homogenate maintained almost unchanged after it was incubated at room temperature for 30 min. Treatment with an ultrasonic processor clearly dropped down the virus infectivity, while a disperser not. Obvious spills and slashes of live viruses were observed in processes of homogenization with those two apparatuses. The contamination radii are positively related with sample volume, output energy of operator and handling time. CONCLUSION: Homogenizing infectious samples with an ultrasonic processor and a tissue disperser at commonly used conditions caused obvious spills and splashes of live viruses, which possesses high risk to induce Laboratory acquired infections (LAIs).

[Preliminary studies on pathogenic microorganisms laboratory-acquired infections cases in recent years and its control strategies].

OBJECTIVE: To analyze and study types, infections routes and causes of global pathogenic microorganisms laboratory-acquired infections cases reported in the literatures from 2000 to 2009 and to discuss prevention and control strategies. METHODS: (1) Pathological observation of hepatic specimens: hepatic tissue pathogenic microorganisms laboratory-acquired infections. Methods PubMed, Embase, Biosis and Webs of Science covering SCIE, SSCI, CPCI-S and CPCI-SSH are chosen as data sources, "laboratory-acquired (associated) infections" are searched as the key words to search laboratory-acquired infections literature published from 2000 to 2009, from which information and data are accessed to be collected, analyzed and researched. RESULTS: There are 19 species of pathogenic microorganisms causing laboratory-acquired infections in the last 10 years, including 15 species of bacteria, accounting for 78.9%; 4 species of virus, accounting for 21.1%. There are 83 cases reported, of which there are 60 bacterial cases, accounting for 72.3%; and 23 virus cases, accounting for 27.7%. Ingestion and inhalation are main routes of infections, respectively accounting for 32.5% and 31.3%, which are mainly due to accidents, accounting for 47.0%. CONCLUSION: In recent years, pathogenic microbiology laboratory-acquired infections continue to occur, and it is mainly due to accidental infections, which expose laboratory workers' low sense of safety and deficient operation methods. Laboratory staff should strengthen their senses of safety and comply with safe operation procedures, which are still the key to prevent laboratory-acquired infections.

[Correlation between human papillomavirus type 16 infection and human leukocyte antigen class I expression in cervical cancers of Uighur women].

OBJECTIVE: To explore the relationship between human papillomavirus(HPV) infection and expression of human leukocyte antigen class I (HLA-I) family genes (HLA-A, B and C) in cervical cancers of Uighur women, and to investigate their effect on cervical cancer progression. METHODS: Fresh tissue samples of 78 Uighur women with cervical squamous carcinoma, cervical intraepithelial neoplasia (CIN) or benign cervicitis were selected. HLA-A, B and C expression and HPV infection were analyzed using RT-PCR and HPV gene chips, respectively. RESULTS: There was a tendency of increasing the total loss of HLA-A, B and C mRNA as the cervical lesions became more aggressive. Loss of HLA-I mRNA in CIN (I, II and III) and cervical squamous carcinoma was 70.0% (14/20) and 84.8% (39/46) respectively. Poorly differentiated cervical carcinomas had the highest HLA-I expression loss (90.6%). In contrast, HLA-I mRNA loss was seen in only 8% of cases of cervicitis. Moreover, it was found that high risk HPV 16 infection was strongly correlated with the loss HLA-I mRNA expression (r = 0.803, P < 0.01). CONCLUSIONS: The loss of HLA-I gene expression is strongly correlated with HPV-16 infection, and may serve as a biomarker of cervical cancer progression in Uighur women.

[Apoptosis induced in vitro by dexamethasone and ATP in the protoscolex of Echinococcus granulosus].

OBJECTIVE: To explore the apoptosis induced by dexamethasone and adenosine triphosphate (ATP) in protoscolex of Echinococcus granulosus. METHODS: Protoscoleces were cultured in vitro and used for the experiment in 4 groups: dexamethasone (5 mmol/L) group, ATP (1.6 mmol/L) group, dexamethasone (5 mmol/L)+ATP (1.6 mmol/L) group, and RPMI 1640 medium as control group. The morphology of protoscolex was observed by light microscopy. After drug treatment for 8 h, the group with significant morphological changes in protoscolex was selected to observe the ultrastructure of protoscolex by transmission electron microscopy. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay (TUNEL) was employed to observe the apoptosis. Caspase-3 activity was detected with a kit, and DNA fragments were seperated by agarose gel electrophoresis. RESULTS: After induced for 8 h, the protoscoleces shrank in dexamethasone group and dexamethasone+ATP group, the rostellum was invaginated. Compared with the control, the calcareous corpuscles in the protoscolex significantly reduced and blurred in the two groups The morphological changes in protoscolex of dexamethasone+ATP group was more obvious than that of dexamethasone group. Electron microscopy showed that dexamethasone+ATP-treated protoscoleces possessed typical morphological features of apoptosis, including the cell volume reduction with densified cytoplasm, cell membrane blebbing, and nuclear heterochromatin peripheral aggregation below the nuclear membrane. A few apoptotic cells were found in protoscolex of dexamethasone+ATP group by TUNEL, while none in the control. Caspase-3 activity significantly increased 12-fold compared to the control. About 150 bp DNA fragment exhibited the typical DNA ladder formation characteristic for apoptosis in dexamethasone+ATP group. CONCLUSION: Apoptosis in the protoscolex of E. granulosus may be induced by dexamethasone and ATP in vitro.

[Study on the phenomenon of splashes and sprays from virology].

OBJECTIVE: To investigate the phenomenon of accidental splashes and sprays from manipulation of recombinant virus material and to measure the approximate spilled distance when recombinant virus material inadvertently dropped in the biosafety laboratory. METHODS: first, two groups owning different experience simulated the course of accidental spills and splashes by recombinant adenovirus (rADV) which expressed green fluorescence protein (GFP), the GFP signal were observed in 96 well cell plate after spills appeared; Second, the routine two heights (75 cm and 110 cm) and capacity (1 ml, 1.5 ml, 4 ml and 8 ml) of virus were chose to simulate the experiment of unexpected dropping. RESULTS: First, the positive quantity of the first group owning 5 years' experience is much less than the second group owning 2 years' work experience, the former was 7 positive wells, the latter was 81 positive when they used the pipette to operation. Second, when the unclosed test tubes (1 ml, 1.5 ml, 4 ml and 8 ml recombinant virus) inadvertently dropped, the largest spill distance was 0.92 m, 1.57 m, 2.63 m and2.68 m respectively. CONCLUSION: The better experience is important to make sure safety when we make infectious material; the contaminated distance increased with the amount of recombinant virus material.

[Investigating the risk of two model virus in the laboratory].

OBJECTIVE: To study the survival time of recombination rival in environment and inactivation ability of different disinfectant and ultraviolet radiation against virus. METHODS: NC membranes absorbed the recombinant adenovirus (rADV) or herpes simplex virus (rHSV) with green fluorescence protein (GFP) were laid, or immersed in various concentration of different disinfectants such as ethanol, sodium hypochlorite, lysol and geramine and then taked out them every 15 min, or exposed under ultraviolet radiation, then the NC membranes were adsorbed 1 h in cell, 37 degrees C 5% CO2 48 h. The results were observed under the fluorescence microscope. RESULTS: (1) the average survival time of rHSV under environment is less than 60 min, rADV is almost up to 2 h. (2) The infection ability of rHSV and rADV was inactived 15 min by both ethanol (100%, 70% and 50%) and sodium hypochlorite (5%, 2.5% and 1.25%). (3) Two virus can be killed by 0.1% bromogeramine. (4) Both 5% and 2.5% lysol, but rADV can not lost the infection on Vero Cell until 75 min by 1.25% Lysol. (5) The rHSV was inactivated under ultraviolet radiation, but rADV was not. CONCLUSION: The survival time of is different from both envelope rival and the no-envelope viral under nature environment and the inactivate ability of disinfectant also is different between two model virus; Disinfectant should be choose according to virus type.