To detect retrospectively the phenotype and stability of the E-protein gene in Japanese Encephalitis (JE) virus strain SA14-14-2 used in the live-attenuated JE vaccine prepared at different years, the viral titer was ...To detect retrospectively the phenotype and stability of the E-protein gene in Japanese Encephalitis (JE) virus strain SA14-14-2 used in the live-attenuated JE vaccine prepared at different years, the viral titer was titrated by plaque formation in BHK-21 cell cultures, and the neuro-virulence of viruses was assayed in mice with body weight of 12-14 g by intracerebral inoculation. Meanwhile, the total RNA of virus gene was extracted and amplified by RT-PCR with the designed primers, and then it was purified and cloned to the expression vector pGEM-T. The recombinant plasmid was purified and sequenced. It was found that the loss of viral titer of vaccines stored in -20℃ for longer than 10 years was less than 0.5 Lg PFU/ml. No mice inoculated intracerebrally showed signs of illness or even death. The size of plagues of the vaccine virus remained to be small, and the E genes of primary virus seed SA14-14-2 and the vaccines prepared at different years (1987-2001) were unchanged, including the 8 critical amino acid sites which were different from the parent wild virus strain SA14 and the related neuro-virulence. These results indicate that the genotypic and biological characteristics of the attenuated JE virus strain SA14-14-2 and its vaccines prepared are quite stable without any reversion noted.展开更多
We developed an H5/H7 trivalent inactivated vaccine by using Re-11, Re-12, and H7-Re2 vaccine seed viruses, which were generated by reverse genetics and derived their HA genes from A/duck/Guizhou/S4184/2017(H5N6) (DK/...We developed an H5/H7 trivalent inactivated vaccine by using Re-11, Re-12, and H7-Re2 vaccine seed viruses, which were generated by reverse genetics and derived their HA genes from A/duck/Guizhou/S4184/2017(H5N6) (DK/GZ/S4184/17) (a clade 2.3.4.4d virus), A/chicken/Liaoning/SD007/2017(H5N1) (CK/LN/SD007/17) (a clade 2.3.2.1d virus), and A/chicken/ Guangxi/SD098/2017(H7N9) (CK/GX/SD098/17), respectively. The protective efficacy of this novel vaccine and that of the recently used H5/H7 bivalent inactivated vaccine against different H5 and H7N9 viruses was evaluated in chickens. We found that the H5/H7 bivalent vaccine provided solid protection against the H7N9 virus CK/GX/SD098/17, but only 50–60% protection against different H5 viruses. In contrast, the novel H5/H7 trivalent vaccine provided complete protection against the H5 and H7 viruses tested. Our study underscores the importance of timely updating of vaccines for avian influenza control.展开更多
Some H5 viruses isolated in poultry or wild birds between 2020 and 2021 were found to be antigenically different from the vaccine strains(H5-Re11 and H5-Re12) used in China. In this study, we generated three new recom...Some H5 viruses isolated in poultry or wild birds between 2020 and 2021 were found to be antigenically different from the vaccine strains(H5-Re11 and H5-Re12) used in China. In this study, we generated three new recombinant vaccine seed viruses by using reverse genetics and used them for vaccine production. The vaccine strain H5-Re13 contains the hemagglutinin(HA) and neuraminidase(NA) genes of an H5 N6 virus that bears the clade 2.3.4.4 h HA gene, H5-Re14 contains the HA and NA genes of an H5 N8 virus that bears the clade 2.3.4.4 b HA gene, and H7-Re4 contains the HA and NA genes of H7 N9 virus detected in 2021. We evaluated the protective efficacy of the novel H5/H7 trivalent inactivated vaccine in chickens, ducks, and geese. The inactivated vaccine was immunogenic and induced substantial antibody responses in the birds tested. Three weeks after vaccination, chickens were challenged with five different viruses detected in 2020 and 2021: three viruses(an H5 N1 virus, an H5 N6 virus, and an H5 N8 virus) bearing the clade 2.3.4.4 b HA gene, an H5 N6 virus bearing the clade 2.3.4.4 h HA gene, and an H7 N9 virus. All of the control birds shed high titers of virus and died within 4 days post-challenge, whereas the vaccinated chickens were completely protected from these viruses. Similar protective efficacy against H5 viruses bearing the clade 2.3.4.4 h or 2.3.4.4 b HA gene was observed in ducks and geese. Our study indicates that the newly updated H5/H7 vaccine can provide solid protection against the H5 and H7 N9 viruses that are currently circulating in nature.展开更多
Objective To prepare the 4 candidate vaccine strains of H5N1 avian influenza virus isolated in China Methods Recombinant viruses were rescued using reverse genetics. Neuraminidase (NA) and hemagglutinin (HA) segme...Objective To prepare the 4 candidate vaccine strains of H5N1 avian influenza virus isolated in China Methods Recombinant viruses were rescued using reverse genetics. Neuraminidase (NA) and hemagglutinin (HA) segments of the A/Xinjiang/1/2006, A/Guangxi/1/2009, A/Hubei/1/2010, and A/Guangdong/1/2011 viruses were amplified by RT-PCR. Multibasic amino acid cleavage site of HA was removed and ligated into the pCIpoll vector for virus rescue. The recombinant viruses were evaluated by trypsin dependent assays. Their embnjonate survival and antigenicity were compared with those of the respective wild-type viruses. Results The 4 recombinant viruses showed similar antigenicity compared with wild-type viruses, chicken embryo survival and trypsin-dependent characteristics. Conclusion The 4 recombinant viruses rescued using reverse genetics meet the criteria for classification of low pathogenic avian influenza strains, thus supporting the use of them for the development of seeds and production of pre-pandemic vaccines.展开更多
BACKGROUND Japanese encephalitis virus(JEV),a mosquito borne flavivirus,is the leading cause of viral encephalitis in Asia,in terms of frequency and severity.JEV infection is thought to confer lifelong immunity.With t...BACKGROUND Japanese encephalitis virus(JEV),a mosquito borne flavivirus,is the leading cause of viral encephalitis in Asia,in terms of frequency and severity.JEV infection is thought to confer lifelong immunity.With the near eradication of poliomyelitis,JEV is now the continent’s leading cause of childhood viral neurologic infection and disability.The most common clinical manifestation of JEV infection is acute encephalitis,and currently there is no specific antiviral therapy.Japanese Encephalitis Vaccine(JE-VC)is an effective prevention measure,including JE-VC,Live(JE-MB),and Inactivated JE-VC.CASE SUMMARY A 9-mo-old girl received injection of Inactivated JE-VC(Vero cell)(Liaoning Chengda,batch number 201611B17)on August 31,2017.On that night,she developed a fever with the body temperature up to 38.5°C,for which Ibuprofen Suspension Drops 1.25 mL was given as antipyretic treatment.On September 1,the patient developed apocleisis,and her parents noticed herpes in her oral cavity.The patient was sent to our hospital on September 3.Physical examination led to a diagnosis of herpetic stomatitis,for which Stomatitis Spray 1 puff,tid,Kangfuxin Liquid 2 mL,tid,and vitamin B20.5 tablet,tid,were prescribed.Routine blood tests for low fever on September 6,2017 revealed an absolute neutrophil count(ANC)of 0.62×109/L,hemoglobin(Hb)of 109 g/L,and platelet count(PLT)of 308×10^(12)/L,and the tests were monitored regularly thereafter.The patient was followed until July 26,2020,when routine blood tests revealed ANC 1.72×109/L,Hb 138 g/L,and PLT 309×1012/L,indicating that the neutropenia count had normalized.CONCLUSION This report attempts to bring to clinical attention that Inactivated JE-VC(Vero cell)might cause prolonged granulocytopenia or even agranulocytosis.展开更多
E1 Tor Vibrio cholerae (EVC) strains may be classifled into two kinds-epidemigenic (EEVC) strains and non-epidemigenic (NEEVC) strains-based on a phage-biotyping system. A large number of EEVC strains have been screen...E1 Tor Vibrio cholerae (EVC) strains may be classifled into two kinds-epidemigenic (EEVC) strains and non-epidemigenic (NEEVC) strains-based on a phage-biotyping system. A large number of EEVC strains have been screened for toxigenic and putative colonization attributes. One such naturally occurring strain (designated IEM 101) has been found which is devoid of genes encoding cholera toxin (CT), accessory cholera enterotoxin (ACE), zonula occludens toxin (ZOT), but possesses RS1 sequences and toxin-coregulated pilus A gene (tcpA) although tcpA is poorly expressed. It expresses type B pili but does not posses type C pili. It is an E1 Tor Ogawa strain and does not cause fluid accumulation in rabbit ileal loop tests. Active immunization of rabbits with strain IEM 101 elicited good protection against challenge with virulent strains of V cholerae O1. Oral administrationcaused no side effects in 15 human volunteers, colonized the gut for four to ten days and elicited good immune responses展开更多
Classical swine fever (CSF), a list A disease of Office International des Epizooties, is caused by classical swine fever virus (CSFV) belonging to the Flaviviridae family. The well-known lapinized Chinese strain o...Classical swine fever (CSF), a list A disease of Office International des Epizooties, is caused by classical swine fever virus (CSFV) belonging to the Flaviviridae family. The well-known lapinized Chinese strain of CSFV, also known as C-strain, was developed in China in the mid-1950s. In the past half a century, the vaccine has been proved to be safe and immunogenic in pigs of essentially any age. It is of high efficacy, providing immunized animals with broad-spectrum, sometimes lifelong, protection, which is contributed by both cell-mediated immunity and humoral immunity, against essentially all genotypes or subgenotypes of the virus. The maternal antibodies derived from immunized sows can confer solid protection of their offspring from disease; however, they have been proved to inhibit the successful active immunization of C-strain vaccine. The complete genomes of C-strain and dozens of established or field strains have been sequenced and annotated. Recently, the reverse genetics system of C-strain has been developed, resulting in several C- strain-derived candidate marker vaccines. Many countries manage to control or even eradicate CSF with the aid of mass vaccination with C-strain. in spite of these efforts, the eradication of the disease worldwide remains a big challenge and needs to go a long way, and provably still resorts to genetically modified C-strain vaccine. The authors present an overview of the characteristics of the vaccine, which has stood the test of half a century.展开更多
Effects of attenuated highly pathogenic pig reproductive and respiratory syndrome(HP-PRRS)TJM-F92 strain vaccine on immune antibody level against classical swine fever(CSF)and foot-and-mouth disease(FMD)were stu...Effects of attenuated highly pathogenic pig reproductive and respiratory syndrome(HP-PRRS)TJM-F92 strain vaccine on immune antibody level against classical swine fever(CSF)and foot-and-mouth disease(FMD)were studied from October 8 to November 12 in 2014,in order to optimize vaccination program of CSF,HP-PRRS and FMD and to provide scientific guidance for animal disease control and prevention work.The results showed that attenuated HP-PRRS(TJMF92 strain)vaccine had no significant effect on immune antibody level of hog cholera lapinized virus(HCLV,ST passage cell vaccine)attenuated vaccine and FMD-O inactivated vaccines(OZK/93 strain),and single or combined use of three vaccines received good immunization effects.展开更多
Tick-borne encephalitis is an infection of central nervous system caused by tick-borne encephalitis virus transmitted to humans predominantly by tick bites. During the last few decades the incidence of the disease has...Tick-borne encephalitis is an infection of central nervous system caused by tick-borne encephalitis virus transmitted to humans predominantly by tick bites. During the last few decades the incidence of the disease has been increasing and poses a growing health problem in almost all endemic European and Asian countries. Most cases occur during the highest period of tick activity, in Central Europe mainly from April to November. Tickborne encephalitis is more common in adults than in children. Clinical spectrum of the disease ranges from mild meningitis to severe meningoencephalitis with or without paralysis. Rare clinical manifestations are an abortive form of the disease and a chronic progressive form. A post-encephalitic syndrome, causing long-lasting morbidity that often affects the quality of life develops in up to 50% of patients after acute tick-borne encephalitis. Clinical course and outcome vary by subtype of tick-borne encephalitis virus(the disease caused by the European subtype has milder course and better outcome than the disease caused by Siberian and Far-Easter subtypes), age of patients(increasing age is associated with less favorable outcome), and host genetic factors. Since clinical features and laboratory results of blood and cerebrospinal fluid are nonspecific, the diagnosis must be confirmed by microbiologic findings. The routine laboratory confirmation of the tick-borne encephalitis virus infection is based mainly on the detection of specific Ig M and Ig G antibodies in serum(and cerebrospinal fluid), usually by enzyme-linked immunosorbent assay. There is no specific antiviral treatment for tick-borne encephalitis. Vaccination can effectively prevent the disease and is indicated for persons living in or visiting tick-borne encephalitis endemic areas.展开更多
Objective The aim of the study was to establish the contemporary epidemiological characteristics of Japanese encephalitis (JE) in Guizhou Province. Methods A retrospective study of National Notifiable Disease Report...Objective The aim of the study was to establish the contemporary epidemiological characteristics of Japanese encephalitis (JE) in Guizhou Province. Methods A retrospective study of National Notifiable Disease Reporting System (NNDRS) data from 2971 through 2009, was conducted to ascertain the geographical, seasonal, and age distributions of JE incidence in Guizhou Province, China. Results A total of 68 425 JE cases were reported in Guizhou from 1971-2009. The JE cases occurred sporadically in all 9 prefectures of Guizhou, mostly among residents of rural areas. Seasonal distribution of JE remained consistent over the period from 1971-2009 with the main transmission season starting from June to September and peaking in August. JE occurred mainly in children under the age of 15 years with peak incidence in the 0-6-year age group. Pearson's correlation analysis showed that JE vaccine distribution had a negative correlation with JE incidence rates during 1971-2009 (coefficient of correlation=-0.475, P〈O.01). Conclusion Over the period of 1971-2009, the JE incidence rate had declined dramatically in terms of geographical and age distributions due to JE vaccination to children at risk.展开更多
To study the immune effect of recombinant avian influenza virus H5 subtype bivalent inactivated vaccine ( HSN1, Re-6 strain + Re-4 strain) and to provide the basis for formulating reasonable immune procedure of avi...To study the immune effect of recombinant avian influenza virus H5 subtype bivalent inactivated vaccine ( HSN1, Re-6 strain + Re-4 strain) and to provide the basis for formulating reasonable immune procedure of avian influenza vaccine in clinical practice. A total of 12 batches of vaccines from three companies were used for the iannune of SPF chickens and SPF ducks. Each chicken or duck serum was separately collected every 3 weeks until the immunization up to the 24^th week. The serum antibody titers of Re-6 and Re-4 were detected. The results showed that the HI titers of the inoculated SPF chickens and SPF ducks roached the peak when the immune time were the 6^th and 3^rd week after the first immunization respectively; then the titer decreased gradually as time prolonged; the highest titer of SPF chickens was greater than that of SPF ducks; the high titer duration of SPF chickens were longer than that of SPF ducks ; and all the vaccines from the three companies showed a good immune effect.展开更多
Background: There have been no reported studies involving aerosol immunization with 2 of the 3 components of MMR II vaccine—Attenuvax measles vaccine and Jeryl-Lyn mumps vaccine. Objective: To evaluate the safety and...Background: There have been no reported studies involving aerosol immunization with 2 of the 3 components of MMR II vaccine—Attenuvax measles vaccine and Jeryl-Lyn mumps vaccine. Objective: To evaluate the safety and antibody responses to aerosolized Attenuvax measles strain, Jeryl Lynn mumps strain and RA 27/3 rubella component of an MMR vaccine in adults, before assessing the booster administration of this vaccine in children. Methods: A pilot study to evaluate safety and antibody responses of MMR II (Merch Sharp & Dhome Corp., Whitehouse Station, NJ 08889, USA) components administered by aerosol was carried out in 27 healthy adults of 21 to 38 years of age. All participants were followed-up during 28 days following immunization for detection of clinical adverse events. Immune response was evaluated by plaque reduction neutralization test for measles, and commercial ELISA kits for rubella and mumps. Results: Only mild clinical adverse events were noted. Despite high levels of baseline seropositivity to all vaccine components, seroresponses to measles, rubella and mumps occurred in 44%, 15% and 41%, respectively. Conclusions: These outcomes compare favorably with earlier studies of other MMR vaccines given by aerosol. Further evaluations on safety and booster immune response should be performed in children.展开更多
Tick-borne encephalitis(TBE)is a natural focal disease with fatal encephalitis induced by tick-borne encephalitis virus(TBEV),seriously threatening human and public health.Protection of TBE depends on vaccination with...Tick-borne encephalitis(TBE)is a natural focal disease with fatal encephalitis induced by tick-borne encephalitis virus(TBEV),seriously threatening human and public health.Protection of TBE depends on vaccination with inactivated vaccine,which requires high cost and multiple immunizations.Here,we construct genetically engineered bacterial-like particles(BLPs)as an effective TBEV vaccine with simplified immunizations and improved immune efficacy.The TBEV BLPs involve the combination of the gram-positive enhancer matrix from Lactococcus lactis,and TBEV envelope(E)protein expressed by genetically engineered recombinant baculovirus.The prepared TBEV BLPs can effectively stimulate the activation of dendritic cells to present the TBEV E proteins to T and B cells,leading to strong and durable cellular and humoral immune responses in mice.Surprisingly,the serum levels of specific IgG antibodies in mice remain about 10^(6)at 6 months after the secondary immunization.Overall,the TBEV BLPs can be used as a potent vaccine candidate,laying the foundation for developing novel TBEV genetically engineered vaccines.展开更多
Tick-borne encephalitis virus(TBEV)is an important tick-borne pathogen that poses as a serious public health concern.The coverage and immunogenicity of the currently available vaccines against TBEV are relatively low;...Tick-borne encephalitis virus(TBEV)is an important tick-borne pathogen that poses as a serious public health concern.The coverage and immunogenicity of the currently available vaccines against TBEV are relatively low;therefore,it is crucial to develop novel and effective vaccines against TBEV.The present study describes a novel strategy for the assembly of virus-like particles(VLPs)by co-expressing the structural(core/prM/E)and non-structural(NS2B/NS3Pro)proteins of TBEV.The efficacy of the VLPs was subsequently evaluated in C57BL/6 mice,and the resultant IgG serum could neutralize both Far-Eastern and European subtypes of TBEV.These findings indicated that the VLP-based vaccine elicited the production of cross-subtype reactive antibodies.The VLPs provided protection to mice lacking the type I interferon receptor(IFNAR^(-/-))against lethal TBEV challenge,with undetectable viral load in brain and intestinal tissues.Furthermore,the group that received the VLP vaccine did not exhibit significant pathological changes and the inflammatory factors were significantly suppressed compared to the control group.Immunization with the VLP vaccine induced the production of multiple-cytokine-producing antiviral CD4+T cells in vivo,including TNF-α^(+),IL-2^(+),and IFN-γ^(+)T cells.Altogether,the findings suggest that noninfectious VLPs can serve as a potentially safe and effective vaccine candidate against diverse subtypes of TBEV.展开更多
Objective To explore on the immunity of live attenuated Japanese Encephalitis (JE) vaccine (SA14-14-2) to different wild JE virus (JEV) strains.Methods The neutralizing effect of the vaccine against different wild JE ...Objective To explore on the immunity of live attenuated Japanese Encephalitis (JE) vaccine (SA14-14-2) to different wild JE virus (JEV) strains.Methods The neutralizing effect of the vaccine against different wild JE virus strains was detected by plaque reduction neutralization test ( PRNT), and the immunogenicity was studied on mice by vaccination - challenge protection test. In the PRNT , pooled sera from vaccinated human were tested against 10 strains of JEV , one isolated in Taiwan and 9 from other Asian countries. In the vaccination challenge test, mice received one dose of the live vaccine subcutaneously and were challenged intraperitoneally 14 days later against 22 JEV virus strains, 11 were isolated in China and the other 11 from Tailand, Vietnahailam, Indonesia, India, Philippines and Japan.Results The protection rates to all the 22 challenge virus were 90% -100% when 340 PFU/0.1 ml vaccinate virus was administered. The neutralizing effect showed that all the JEV isolates many have neutralized by the sera.Conclusion SA14-14-2 live attenuated prepared with strain SA14-14-2 is broadly immunogenic and mav have effective protection against in Asian JE affected countries.展开更多
文摘To detect retrospectively the phenotype and stability of the E-protein gene in Japanese Encephalitis (JE) virus strain SA14-14-2 used in the live-attenuated JE vaccine prepared at different years, the viral titer was titrated by plaque formation in BHK-21 cell cultures, and the neuro-virulence of viruses was assayed in mice with body weight of 12-14 g by intracerebral inoculation. Meanwhile, the total RNA of virus gene was extracted and amplified by RT-PCR with the designed primers, and then it was purified and cloned to the expression vector pGEM-T. The recombinant plasmid was purified and sequenced. It was found that the loss of viral titer of vaccines stored in -20℃ for longer than 10 years was less than 0.5 Lg PFU/ml. No mice inoculated intracerebrally showed signs of illness or even death. The size of plagues of the vaccine virus remained to be small, and the E genes of primary virus seed SA14-14-2 and the vaccines prepared at different years (1987-2001) were unchanged, including the 8 critical amino acid sites which were different from the parent wild virus strain SA14 and the related neuro-virulence. These results indicate that the genotypic and biological characteristics of the attenuated JE virus strain SA14-14-2 and its vaccines prepared are quite stable without any reversion noted.
基金This work was supported by the National Key R&D Program of China(2016YFD0501602,2017YFD0500701,and 2016YFEO203200)the National Natural Science Foundation of China(3167131307)+1 种基金the China Agriculture Research System(CARS-41-G12)and Central Publicinterest Scientific Institution Basal Research Fund(1610302017001).
文摘We developed an H5/H7 trivalent inactivated vaccine by using Re-11, Re-12, and H7-Re2 vaccine seed viruses, which were generated by reverse genetics and derived their HA genes from A/duck/Guizhou/S4184/2017(H5N6) (DK/GZ/S4184/17) (a clade 2.3.4.4d virus), A/chicken/Liaoning/SD007/2017(H5N1) (CK/LN/SD007/17) (a clade 2.3.2.1d virus), and A/chicken/ Guangxi/SD098/2017(H7N9) (CK/GX/SD098/17), respectively. The protective efficacy of this novel vaccine and that of the recently used H5/H7 bivalent inactivated vaccine against different H5 and H7N9 viruses was evaluated in chickens. We found that the H5/H7 bivalent vaccine provided solid protection against the H7N9 virus CK/GX/SD098/17, but only 50–60% protection against different H5 viruses. In contrast, the novel H5/H7 trivalent vaccine provided complete protection against the H5 and H7 viruses tested. Our study underscores the importance of timely updating of vaccines for avian influenza control.
基金supported by the National Key Research and Development Program of China(2021YFD1800200)the Laboratory for Lingnan Modern Agriculture Project(NT2021007)the China Agriculture Research System of the MOF and MARA(CARS-41-G12)。
文摘Some H5 viruses isolated in poultry or wild birds between 2020 and 2021 were found to be antigenically different from the vaccine strains(H5-Re11 and H5-Re12) used in China. In this study, we generated three new recombinant vaccine seed viruses by using reverse genetics and used them for vaccine production. The vaccine strain H5-Re13 contains the hemagglutinin(HA) and neuraminidase(NA) genes of an H5 N6 virus that bears the clade 2.3.4.4 h HA gene, H5-Re14 contains the HA and NA genes of an H5 N8 virus that bears the clade 2.3.4.4 b HA gene, and H7-Re4 contains the HA and NA genes of H7 N9 virus detected in 2021. We evaluated the protective efficacy of the novel H5/H7 trivalent inactivated vaccine in chickens, ducks, and geese. The inactivated vaccine was immunogenic and induced substantial antibody responses in the birds tested. Three weeks after vaccination, chickens were challenged with five different viruses detected in 2020 and 2021: three viruses(an H5 N1 virus, an H5 N6 virus, and an H5 N8 virus) bearing the clade 2.3.4.4 b HA gene, an H5 N6 virus bearing the clade 2.3.4.4 h HA gene, and an H7 N9 virus. All of the control birds shed high titers of virus and died within 4 days post-challenge, whereas the vaccinated chickens were completely protected from these viruses. Similar protective efficacy against H5 viruses bearing the clade 2.3.4.4 h or 2.3.4.4 b HA gene was observed in ducks and geese. Our study indicates that the newly updated H5/H7 vaccine can provide solid protection against the H5 and H7 N9 viruses that are currently circulating in nature.
基金supported by the National High Technology Research and Development Program of China(863 Program)SQ2009AA02XK1487370
文摘Objective To prepare the 4 candidate vaccine strains of H5N1 avian influenza virus isolated in China Methods Recombinant viruses were rescued using reverse genetics. Neuraminidase (NA) and hemagglutinin (HA) segments of the A/Xinjiang/1/2006, A/Guangxi/1/2009, A/Hubei/1/2010, and A/Guangdong/1/2011 viruses were amplified by RT-PCR. Multibasic amino acid cleavage site of HA was removed and ligated into the pCIpoll vector for virus rescue. The recombinant viruses were evaluated by trypsin dependent assays. Their embnjonate survival and antigenicity were compared with those of the respective wild-type viruses. Results The 4 recombinant viruses showed similar antigenicity compared with wild-type viruses, chicken embryo survival and trypsin-dependent characteristics. Conclusion The 4 recombinant viruses rescued using reverse genetics meet the criteria for classification of low pathogenic avian influenza strains, thus supporting the use of them for the development of seeds and production of pre-pandemic vaccines.
文摘BACKGROUND Japanese encephalitis virus(JEV),a mosquito borne flavivirus,is the leading cause of viral encephalitis in Asia,in terms of frequency and severity.JEV infection is thought to confer lifelong immunity.With the near eradication of poliomyelitis,JEV is now the continent’s leading cause of childhood viral neurologic infection and disability.The most common clinical manifestation of JEV infection is acute encephalitis,and currently there is no specific antiviral therapy.Japanese Encephalitis Vaccine(JE-VC)is an effective prevention measure,including JE-VC,Live(JE-MB),and Inactivated JE-VC.CASE SUMMARY A 9-mo-old girl received injection of Inactivated JE-VC(Vero cell)(Liaoning Chengda,batch number 201611B17)on August 31,2017.On that night,she developed a fever with the body temperature up to 38.5°C,for which Ibuprofen Suspension Drops 1.25 mL was given as antipyretic treatment.On September 1,the patient developed apocleisis,and her parents noticed herpes in her oral cavity.The patient was sent to our hospital on September 3.Physical examination led to a diagnosis of herpetic stomatitis,for which Stomatitis Spray 1 puff,tid,Kangfuxin Liquid 2 mL,tid,and vitamin B20.5 tablet,tid,were prescribed.Routine blood tests for low fever on September 6,2017 revealed an absolute neutrophil count(ANC)of 0.62×109/L,hemoglobin(Hb)of 109 g/L,and platelet count(PLT)of 308×10^(12)/L,and the tests were monitored regularly thereafter.The patient was followed until July 26,2020,when routine blood tests revealed ANC 1.72×109/L,Hb 138 g/L,and PLT 309×1012/L,indicating that the neutropenia count had normalized.CONCLUSION This report attempts to bring to clinical attention that Inactivated JE-VC(Vero cell)might cause prolonged granulocytopenia or even agranulocytosis.
文摘E1 Tor Vibrio cholerae (EVC) strains may be classifled into two kinds-epidemigenic (EEVC) strains and non-epidemigenic (NEEVC) strains-based on a phage-biotyping system. A large number of EEVC strains have been screened for toxigenic and putative colonization attributes. One such naturally occurring strain (designated IEM 101) has been found which is devoid of genes encoding cholera toxin (CT), accessory cholera enterotoxin (ACE), zonula occludens toxin (ZOT), but possesses RS1 sequences and toxin-coregulated pilus A gene (tcpA) although tcpA is poorly expressed. It expresses type B pili but does not posses type C pili. It is an E1 Tor Ogawa strain and does not cause fluid accumulation in rabbit ileal loop tests. Active immunization of rabbits with strain IEM 101 elicited good protection against challenge with virulent strains of V cholerae O1. Oral administrationcaused no side effects in 15 human volunteers, colonized the gut for four to ten days and elicited good immune responses
文摘Classical swine fever (CSF), a list A disease of Office International des Epizooties, is caused by classical swine fever virus (CSFV) belonging to the Flaviviridae family. The well-known lapinized Chinese strain of CSFV, also known as C-strain, was developed in China in the mid-1950s. In the past half a century, the vaccine has been proved to be safe and immunogenic in pigs of essentially any age. It is of high efficacy, providing immunized animals with broad-spectrum, sometimes lifelong, protection, which is contributed by both cell-mediated immunity and humoral immunity, against essentially all genotypes or subgenotypes of the virus. The maternal antibodies derived from immunized sows can confer solid protection of their offspring from disease; however, they have been proved to inhibit the successful active immunization of C-strain vaccine. The complete genomes of C-strain and dozens of established or field strains have been sequenced and annotated. Recently, the reverse genetics system of C-strain has been developed, resulting in several C- strain-derived candidate marker vaccines. Many countries manage to control or even eradicate CSF with the aid of mass vaccination with C-strain. in spite of these efforts, the eradication of the disease worldwide remains a big challenge and needs to go a long way, and provably still resorts to genetically modified C-strain vaccine. The authors present an overview of the characteristics of the vaccine, which has stood the test of half a century.
文摘Effects of attenuated highly pathogenic pig reproductive and respiratory syndrome(HP-PRRS)TJM-F92 strain vaccine on immune antibody level against classical swine fever(CSF)and foot-and-mouth disease(FMD)were studied from October 8 to November 12 in 2014,in order to optimize vaccination program of CSF,HP-PRRS and FMD and to provide scientific guidance for animal disease control and prevention work.The results showed that attenuated HP-PRRS(TJMF92 strain)vaccine had no significant effect on immune antibody level of hog cholera lapinized virus(HCLV,ST passage cell vaccine)attenuated vaccine and FMD-O inactivated vaccines(OZK/93 strain),and single or combined use of three vaccines received good immunization effects.
文摘Tick-borne encephalitis is an infection of central nervous system caused by tick-borne encephalitis virus transmitted to humans predominantly by tick bites. During the last few decades the incidence of the disease has been increasing and poses a growing health problem in almost all endemic European and Asian countries. Most cases occur during the highest period of tick activity, in Central Europe mainly from April to November. Tickborne encephalitis is more common in adults than in children. Clinical spectrum of the disease ranges from mild meningitis to severe meningoencephalitis with or without paralysis. Rare clinical manifestations are an abortive form of the disease and a chronic progressive form. A post-encephalitic syndrome, causing long-lasting morbidity that often affects the quality of life develops in up to 50% of patients after acute tick-borne encephalitis. Clinical course and outcome vary by subtype of tick-borne encephalitis virus(the disease caused by the European subtype has milder course and better outcome than the disease caused by Siberian and Far-Easter subtypes), age of patients(increasing age is associated with less favorable outcome), and host genetic factors. Since clinical features and laboratory results of blood and cerebrospinal fluid are nonspecific, the diagnosis must be confirmed by microbiologic findings. The routine laboratory confirmation of the tick-borne encephalitis virus infection is based mainly on the detection of specific Ig M and Ig G antibodies in serum(and cerebrospinal fluid), usually by enzyme-linked immunosorbent assay. There is no specific antiviral treatment for tick-borne encephalitis. Vaccination can effectively prevent the disease and is indicated for persons living in or visiting tick-borne encephalitis endemic areas.
基金supported by a grant from NIP of Center for Disease Control and Prevention of China
文摘Objective The aim of the study was to establish the contemporary epidemiological characteristics of Japanese encephalitis (JE) in Guizhou Province. Methods A retrospective study of National Notifiable Disease Reporting System (NNDRS) data from 2971 through 2009, was conducted to ascertain the geographical, seasonal, and age distributions of JE incidence in Guizhou Province, China. Results A total of 68 425 JE cases were reported in Guizhou from 1971-2009. The JE cases occurred sporadically in all 9 prefectures of Guizhou, mostly among residents of rural areas. Seasonal distribution of JE remained consistent over the period from 1971-2009 with the main transmission season starting from June to September and peaking in August. JE occurred mainly in children under the age of 15 years with peak incidence in the 0-6-year age group. Pearson's correlation analysis showed that JE vaccine distribution had a negative correlation with JE incidence rates during 1971-2009 (coefficient of correlation=-0.475, P〈O.01). Conclusion Over the period of 1971-2009, the JE incidence rate had declined dramatically in terms of geographical and age distributions due to JE vaccination to children at risk.
基金Supported by Shandong Winning Project of Quality Monitoring of Avian Influenza Vaccine
文摘To study the immune effect of recombinant avian influenza virus H5 subtype bivalent inactivated vaccine ( HSN1, Re-6 strain + Re-4 strain) and to provide the basis for formulating reasonable immune procedure of avian influenza vaccine in clinical practice. A total of 12 batches of vaccines from three companies were used for the iannune of SPF chickens and SPF ducks. Each chicken or duck serum was separately collected every 3 weeks until the immunization up to the 24^th week. The serum antibody titers of Re-6 and Re-4 were detected. The results showed that the HI titers of the inoculated SPF chickens and SPF ducks roached the peak when the immune time were the 6^th and 3^rd week after the first immunization respectively; then the titer decreased gradually as time prolonged; the highest titer of SPF chickens was greater than that of SPF ducks; the high titer duration of SPF chickens were longer than that of SPF ducks ; and all the vaccines from the three companies showed a good immune effect.
文摘Background: There have been no reported studies involving aerosol immunization with 2 of the 3 components of MMR II vaccine—Attenuvax measles vaccine and Jeryl-Lyn mumps vaccine. Objective: To evaluate the safety and antibody responses to aerosolized Attenuvax measles strain, Jeryl Lynn mumps strain and RA 27/3 rubella component of an MMR vaccine in adults, before assessing the booster administration of this vaccine in children. Methods: A pilot study to evaluate safety and antibody responses of MMR II (Merch Sharp & Dhome Corp., Whitehouse Station, NJ 08889, USA) components administered by aerosol was carried out in 27 healthy adults of 21 to 38 years of age. All participants were followed-up during 28 days following immunization for detection of clinical adverse events. Immune response was evaluated by plaque reduction neutralization test for measles, and commercial ELISA kits for rubella and mumps. Results: Only mild clinical adverse events were noted. Despite high levels of baseline seropositivity to all vaccine components, seroresponses to measles, rubella and mumps occurred in 44%, 15% and 41%, respectively. Conclusions: These outcomes compare favorably with earlier studies of other MMR vaccines given by aerosol. Further evaluations on safety and booster immune response should be performed in children.
基金National Key Research and Development Program of China,Grant/Award Number:2021YFC2600202Fundamental Research Funds for the Central Universities,Grant/Award Number:2132020KJC016。
文摘Tick-borne encephalitis(TBE)is a natural focal disease with fatal encephalitis induced by tick-borne encephalitis virus(TBEV),seriously threatening human and public health.Protection of TBE depends on vaccination with inactivated vaccine,which requires high cost and multiple immunizations.Here,we construct genetically engineered bacterial-like particles(BLPs)as an effective TBEV vaccine with simplified immunizations and improved immune efficacy.The TBEV BLPs involve the combination of the gram-positive enhancer matrix from Lactococcus lactis,and TBEV envelope(E)protein expressed by genetically engineered recombinant baculovirus.The prepared TBEV BLPs can effectively stimulate the activation of dendritic cells to present the TBEV E proteins to T and B cells,leading to strong and durable cellular and humoral immune responses in mice.Surprisingly,the serum levels of specific IgG antibodies in mice remain about 10^(6)at 6 months after the secondary immunization.Overall,the TBEV BLPs can be used as a potent vaccine candidate,laying the foundation for developing novel TBEV genetically engineered vaccines.
基金This work was supported by grants from the National Key Research and Development Program of China(grant number:2018YFA0507201 to X.W.C.)the National Science Foundation of China(grant number:32000111 to Q.Y.)the China Postdoctoral Science Foundation(grant number:2020T130021ZX to Q.Y.and grant number:2020M672580 to Q.Y.).
文摘Tick-borne encephalitis virus(TBEV)is an important tick-borne pathogen that poses as a serious public health concern.The coverage and immunogenicity of the currently available vaccines against TBEV are relatively low;therefore,it is crucial to develop novel and effective vaccines against TBEV.The present study describes a novel strategy for the assembly of virus-like particles(VLPs)by co-expressing the structural(core/prM/E)and non-structural(NS2B/NS3Pro)proteins of TBEV.The efficacy of the VLPs was subsequently evaluated in C57BL/6 mice,and the resultant IgG serum could neutralize both Far-Eastern and European subtypes of TBEV.These findings indicated that the VLP-based vaccine elicited the production of cross-subtype reactive antibodies.The VLPs provided protection to mice lacking the type I interferon receptor(IFNAR^(-/-))against lethal TBEV challenge,with undetectable viral load in brain and intestinal tissues.Furthermore,the group that received the VLP vaccine did not exhibit significant pathological changes and the inflammatory factors were significantly suppressed compared to the control group.Immunization with the VLP vaccine induced the production of multiple-cytokine-producing antiviral CD4+T cells in vivo,including TNF-α^(+),IL-2^(+),and IFN-γ^(+)T cells.Altogether,the findings suggest that noninfectious VLPs can serve as a potentially safe and effective vaccine candidate against diverse subtypes of TBEV.
文摘Objective To explore on the immunity of live attenuated Japanese Encephalitis (JE) vaccine (SA14-14-2) to different wild JE virus (JEV) strains.Methods The neutralizing effect of the vaccine against different wild JE virus strains was detected by plaque reduction neutralization test ( PRNT), and the immunogenicity was studied on mice by vaccination - challenge protection test. In the PRNT , pooled sera from vaccinated human were tested against 10 strains of JEV , one isolated in Taiwan and 9 from other Asian countries. In the vaccination challenge test, mice received one dose of the live vaccine subcutaneously and were challenged intraperitoneally 14 days later against 22 JEV virus strains, 11 were isolated in China and the other 11 from Tailand, Vietnahailam, Indonesia, India, Philippines and Japan.Results The protection rates to all the 22 challenge virus were 90% -100% when 340 PFU/0.1 ml vaccinate virus was administered. The neutralizing effect showed that all the JEV isolates many have neutralized by the sera.Conclusion SA14-14-2 live attenuated prepared with strain SA14-14-2 is broadly immunogenic and mav have effective protection against in Asian JE affected countries.