AIM: To analyze the biological role of the surface antigen of Toxoplasma gondii(Tgondii) in development of vaccine. METHODS: The surface antigen of Tgondii (SAG1) was expressed in vitro. The immune response of t...AIM: To analyze the biological role of the surface antigen of Toxoplasma gondii(Tgondii) in development of vaccine. METHODS: The surface antigen of Tgondii (SAG1) was expressed in vitro. The immune response of the host to the antigen was investigated by detection of specific antibody reaction to SAG1 and production of cytokines. Mice were immunized with recombinant SAG1 and challenged with lethal strain of Tgondii RH. The monoclonal antibody to r-SAG1 was prepared and used to study the effects of SAG1 on Tgondii tachyzoites under electromicroscope. RESULTS: The mice immunized with recombinant SAG1 delayed death for 60 h compared to the control group. The recombinant SAG1 induced specific high titer of IgG and IgM antibodies as well as IFN-y, IL-2 and IL-4 cytokines in mice. In contrast, IL-12, IL-6 and TNF-α were undetectable. When T gondii tachyzoites were treated with the monoclonal antibody to r-SAG1, the parasites were gathered together, destroyed, deformed, swollen, and holes and gaps formed on the surface. CONCLUSION: SAG1 may be an excellent vaccine candidate against T gondii. The immune protection induced by SAG1 against Tgondii may be regulated by both hormone- and cell-mediated immune response.展开更多
To evaluate how the efficacy of DNA inocutation affects the ability to raise protective immunity against Leptospira. [WT5”BX]Methods.[WT5”BZ] A pair of oligonucleotide primers were designed to amplify the endoflagel...To evaluate how the efficacy of DNA inocutation affects the ability to raise protective immunity against Leptospira. [WT5”BX]Methods.[WT5”BZ] A pair of oligonucleotide primers were designed to amplify the endoflagellar gene of L. interrogans sensu stricto serovar lai. An approximately 840bp fragment was generated with PCR and inserted into VR1012, a plasmid DNA expression vector, after the fragment and VR1012 were digested respectively with EcoRV and Sal I. A recombinant plasmid designated as VR1012+flaB2 was obtained. The vector, VR1012 consits of a pUC18 backbone with the cytomegalovirus(CMV) IE1 enhancer, promoter, and intron A, transcription regulatory elements and the BGH polyadenylation sequences driving the expressing of leptospiral endoflagellar gene of L. interrogans sensu stricto serovar lai. Plasmid encoding leptospiral endoflagellin gene was injected into quadriceps of NZW rabbits. [WT5”BX]Results.[WT5”BZ]This resulted in the generation of specific leptospiral antibody with high ELISA titer (1:32768) in the rabbits. Immuno/protection was performed in guinea pigs without adjuvant. The group“VR1012+flaB2” showed higher survival rate(90%,9/10 animals),compared with the group “VR1012 lack flaB2” and the group “normal saline”. [WT5”BX]Conclusion.[WT5”BZ]The technique of DNA vaccine has potential advantages over certain other vaccine preparation technologies. However whether DNA vaccine will be useful for vaccine development remains to be tested.展开更多
AIM: To detect the biological characters of the SGC7901 gastric cancer cell-dendritic cell fusion vaccines.METHODS: The suspending living SGC7901 gastric cancer cells and dendritic cells were induced to be fusioned ...AIM: To detect the biological characters of the SGC7901 gastric cancer cell-dendritic cell fusion vaccines.METHODS: The suspending living SGC7901 gastric cancer cells and dendritic cells were induced to be fusioned by polyethylene glycol. Pure fusion cells were obtained by selective culture with the HAT/HT culture systems. The fusion cells were counted at different time points of culture and their growth curves were drawn to reflect their proliferative activities. The fusion cells were also cultured in culture medium to investigate whether they could grow into cell clones. MTT method was used to test the stimulating abilities of the fusion cells on T lymphocytes' proliferations. Moreover, the fusion cells were planted into nude mice to observe whether they could grow into new planted tumors in this kind of immunodeficiency animals.RESULTS: The fusion cells had weaker proliferative activity and clone abilities than their parental cells. When they were cultured, the counts of cells did not increase remarkably, nor could they grow into cell clones in culture medium. The fusion cells could not grow into new planted tumors after planted into nude mice. The stimulating abilities of the fusion cells on T lymphocytes' proliferations were remarkably increased than their parental dendritic cells. CONCLUSION: The SGC7901 gastric cancer cell-dendritic cell fusion vaccines have much weaker proliferative abilities than their parental cells, but they keep strong abilities to irritate the T lymphocytes and have no abilities to grow into new planted tumors in immunodeficiency animals. These are the biological basis for their antitumor biotherapies.展开更多
Potency is one of the most important indexes of inactivated vaccines.A number of methods have been established to assay the potency,of which the NIH test and single-dose mouse protection test are the "prescribed ...Potency is one of the most important indexes of inactivated vaccines.A number of methods have been established to assay the potency,of which the NIH test and single-dose mouse protection test are the "prescribed methods".Here,we report a method to semi-quantitatively assay the potency of an inactivated rabies vaccine,which uses fewer animals and takes less time to complete.Depending on the quality requirements of a vaccine(e.g.minimum potency),a rabies reference vaccine is,for example,diluted to the minimum potency,and 50 μL of the dilution is taken to inoculate 10 mice.The same amount of the test rabies vaccine is inoculated into another 10 mice.After two weeks,all mice are bled and serum samples are assayed for viral neutralizing antibody by the fluorescent antibody virus neutralization(FAVN) test.By comparing the median and interquartile range of antibody titers of the reference vaccine with those of the test vaccine,the test vaccine potency can be semi-quantitatively judged as to whether it is in accord with the required quality.The reliability of this method was also confirmed in dogs.The procedure can be recommended for batch potency testing during inactivated rabies vaccine production.展开更多
To study the kinetics in vivo of a Hantaan virus DNA vaccine, we constructed a fusion DNA vaccine, pEGFP/S, by cloning the S segment of Hantavirus into the vector, pEGFP-C1, which encodes Green fluorescent protein EGF...To study the kinetics in vivo of a Hantaan virus DNA vaccine, we constructed a fusion DNA vaccine, pEGFP/S, by cloning the S segment of Hantavirus into the vector, pEGFP-C1, which encodes Green fluorescent protein EGFP. In this report, we provide evidence that pEGFP/S was distributed and persistently expressed for more than 60 days in several organs after inoculation. Our findings suggest that the persistent immune responses induced by a Hantaan virus DNA vaccine are likely due to the plasmid pEGFP/S deposited in vivo, which acts as a booster immunization.展开更多
A simple SI epidemic model with age of vaccination is discussed in this paper.Both vexing birth rate, the mortality rate caused by disease and vaccine waning rate areconsidered in this model. We prove that the global ...A simple SI epidemic model with age of vaccination is discussed in this paper.Both vexing birth rate, the mortality rate caused by disease and vaccine waning rate areconsidered in this model. We prove that the global dynamics is completely determined bythe basic reproductive number R(ψ)(ψ denotes per capita vaccination rate). If R(0) 〈 1,the disease-free equilibrium is a global attractor; If R(ψ) 〈: 1, the disease-free equilibriumis locally asymptotically stable; If R(ψ) :〉 1, an unique endemic equilibrium exists and islocally asymptotically stable under certain condition.展开更多
To evaluate maternal hepatitis B virus (HBV) DNA as risk for perinatal HBV infection among infants of HBV-infected women in California. METHODSRetrospective analysis among infants born to hepatitis B surface antigen (...To evaluate maternal hepatitis B virus (HBV) DNA as risk for perinatal HBV infection among infants of HBV-infected women in California. METHODSRetrospective analysis among infants born to hepatitis B surface antigen (HBsAg)-positive mothers who received post vaccination serologic testing (PVST) between 2005 and 2011 in California. Demographic information was collected from the California Department of Public Health Perinatal Hepatitis B Program databaseand matched to birth certificate records. HBV DNA level and hepatitis B e antigen (HBeAg) status were obtained from three large commercial laboratories in California and provider records if available and matched to mother infant pairs. Univariate analysis compared infected and uninfected infants. Multivariate analysis was restricted to infected infants and controls with complete maternal HBV DNA results using a predefined high HBV DNA level of > 2 × 10<sup>7</sup> IU/mL, a 5:1 ratio of cases to controls and a two-sided confidence level of 95%. RESULTSA total of 17687 infants were born to HBsAg positive mothers in California between Jan 1 2005 and Dec 31, 2011. Among 11473 infants with PVST, only 125 (1.1%) were found to be HBV infected. Among these infected infants, lapses in Advisory Committee on Immunization Practices recommended post exposure prophylaxis (PEP) occurred in only 9 infants. However, PEP errors were not significantly different between infected and uninfected infants. Among the 347 uninfected and infected infants who had maternal HBeAg and HBV DNA level, case-control analysis found HBeAg positivity (70.4% vs 28.9%, OR = 46.76, 95%CI: 6.05-361.32, P < 0.001) and a maternal HBV DNA level ≥ 2 × 10<sup>7</sup> IU/mL (92.6% vs 18.5%, OR = 54.5, 95%CI: 12.22-247.55, P < 0.001) were associated with perinatal HBV infection. In multivariate logistic regression, maternal HBV DNA level ≥ 2 × 10<sup>7</sup> IU/mL was the only significant independent predictor of perinatal HBV infection. CONCLUSIONIn California, transmission is low and most infected infants receive appropriate PEP and vaccination. Maternal HBV DNA ≥ 2 × 10<sup>7</sup> IU/mL is associated with high risk of perinatal infection.展开更多
Torque teno virus(TTV) is a nonenveloped virus containing a single-stranded,circular DNA genome of approximately 3.8kb.We completely synthesized the 3 808 nucleotides of the TTV(SANBAN isolate) genome,which contains a...Torque teno virus(TTV) is a nonenveloped virus containing a single-stranded,circular DNA genome of approximately 3.8kb.We completely synthesized the 3 808 nucleotides of the TTV(SANBAN isolate) genome,which contains a hairpin structure and a GC-rich region.More than 100 overlapping oligonucleotides were chemically synthesized and assembled by polymerase chain assembly reaction(PCA),and the synthesis was completed with splicing by overlap extension(SOEing).This study establishes the methodological basis of the chemical synthesis of a viral genome for use as a live attenuated vaccine or gene therapy vector.展开更多
Genotyping 42 serum samples taken from the pigs in the oubreaks from 2009 to 2013 with RT-PCR and nested RT-PCR, showed more than 80% of samples were positive with Chinese PRRSV clade, and the others were European and...Genotyping 42 serum samples taken from the pigs in the oubreaks from 2009 to 2013 with RT-PCR and nested RT-PCR, showed more than 80% of samples were positive with Chinese PRRSV clade, and the others were European and North American classical PRRSV genotypes. Ten serum samples from unnapprent PRRS herds were examined for antibodies against PRRSV with ELISA and also for PRRSV with RT-PCR. It was clearly that the titer of antibodies against PRRSV by ELISA test could not be used for interpreting PRRSV infection. In despite of PRRS vaccination or non-vaccination, a risk of PRRSV infection and re-infection exist, utilizing RT-PCR in combination with serology will give the producer and veterinarian PRRSV more exact situation in the herds.展开更多
The poliomyelitis is an acute infection produced by the polio virus that affects the human central nervous system. It is transmitted by fecal-oral and respiratory contact.There are two types of vaccine, OPV (live att...The poliomyelitis is an acute infection produced by the polio virus that affects the human central nervous system. It is transmitted by fecal-oral and respiratory contact.There are two types of vaccine, OPV (live attenuated virus) and IPV (inactivated polio virus). Currently, there is a plan of vaccination until the age of 5 with OPV. The children vaccinated expel a virus (derived from the vaccine) to the environment, and some of the people that have oral contact with them, get vaccinated by the herd behavior. Nevertheless, taking into account the lately observed facts about the reversion to virulence of the oral polio vaccine during its circulation in the environment, a change in the current vaccination schedule is being contemplated, where the oral polio vaccine can be replaced by the inactivated vaccine. Nowadays, In Colombia the inactivated oral polio vaccine is recommended for children presenting immune deficiency who are vaccinated with IPV. These children do not expel poliovirus to the environment. This work presents a mathematical model that describes the dynamics of the infection in a population where the two types of vaccination are carried out. The population is divided into two groups of age and Michaelis-Menten interactions. Different strategies of vaccination are simulated and analyzed.展开更多
Albania has been a country with a high prevalence of hepatitis B virus. Hepatitis B vaccine has been introduced nationwide in Albanian Immunization Program in 1994. Hepatitis B is given at birth, as a separate antigen...Albania has been a country with a high prevalence of hepatitis B virus. Hepatitis B vaccine has been introduced nationwide in Albanian Immunization Program in 1994. Hepatitis B is given at birth, as a separate antigen, followed by three doses at 2, 4 and 6 months, where Hepatitis B, starting from 2009, is part of pentavalent vaccine of DTP-HepB-Hib. The aim of this study was to evaluate Immunization Program with Hepatitis B vaccination in order to prove program efficacy, increase public confidence in immunizations and advocate for sustainable immunization programs. Methodology was based on three components such as Immunization coverage surveys, serologic surveys and surveillance for acute cases of Hepatitis B. Results of this study showed that vaccination coverage is really high, more than 95% all over the country and with drop-out rates less than 10%. Anti-HBs levels in immunized children were very high in comparison with unimmunized ones. Incidence of HBV in children 0-14 years old is almost zero. Such results tell us that Hepatitis B vaccination is one of the most fruitful strategies for long term control of Hepatitis B disease.展开更多
CpG oligodeoxynucleotides (CpG ODN) as adjuvant have been extensively studied in recent years. Phosphodiester CpG ODN (PO CpG ODN) can perfectly mimic bacterial DNA in enhancing immune response but are vulnerable ...CpG oligodeoxynucleotides (CpG ODN) as adjuvant have been extensively studied in recent years. Phosphodiester CpG ODN (PO CpG ODN) can perfectly mimic bacterial DNA in enhancing immune response but are vulnerable to nucleases in vivo. This study aimed to evaluate the immunostimulatory potential arid safety of phosphodiester CpG ODN encapsulated in nonphospholipid liposomes. BALB/c mice were immunized intramuscularly with different formulations of liposomes, CpG ODN and hepatitis B surface antigen (HBsAg). The results demonstrated that the encapsulated PO CpG ODN were protected against rapid degradation in vivo and retained their adjuvant activity. PO CpG ODN encapsulated with HBsAg in liposomes induced strong Th1-biased or Th1/Th2 mixed humoral immune response in mice with the magnitude similar to their phosphothioate equivalent in the same formulation. High IFN-gamma production induced by this formulation confirmed the generation of strong cellular immune response. Additionally, co-delivery of HBsAg arid PO CpG ODN improved the immune response over that obtained with separate delivery. Safety experiment showed that liposome-encapsulaed PO CpG ODN and HBsAg caused mild systemic and moderate local adverse reaction. In conclusion, our data shows that PO CpG ODN encapsulated in liposomes fully exhibit their Th1-type adjuvant activity arid act as a potential adjuvant for vaccines.展开更多
The Z 10 and Z 37 strains of hemorrhagic fever with renal syndrome (HFRS) virus and the Mongolian gerbil ( Merions unguiculatus ) kidney cells were used to prepare the inactivated bivalent vaccine. A phase Ⅱ clinical...The Z 10 and Z 37 strains of hemorrhagic fever with renal syndrome (HFRS) virus and the Mongolian gerbil ( Merions unguiculatus ) kidney cells were used to prepare the inactivated bivalent vaccine. A phase Ⅱ clinical trial use of this vaccine was made in 750 Chinese volunteers. The results showed that the side reaction rate was 2.5% and the sero-conversion rate of neutralizing antibodies against Hantaan and Seoul viruses in the inoculated volunteers were 87.6% and 96.3% respectively.展开更多
Coxiella burnetii is the etiological agent of Q fever.To identify its major seroreactive proteins,a subgenomic protein array was developed.A total of 101 assumed virulence-associated recombinant proteins of C.burnetii...Coxiella burnetii is the etiological agent of Q fever.To identify its major seroreactive proteins,a subgenomic protein array was developed.A total of 101 assumed virulence-associated recombinant proteins of C.burnetii were probed with sera from mice experimentally infected with C.burnetii and sera from Q fever patients.Sixteen proteins were recognized as major seroreactive antigens by the mouse sera.Seven of these 16 proteins reacted positively with at least 45% of Q fever patient sera.Notably,HspB had the highest fluorescence intensity value and positive frequency of all the proteins on the array when probed with both Q fever patient sera and mouse sera.These results suggest that these seven major seroreactive proteins,particularly HspB,are potential serodiagnostic and subunit vaccine antigens of Q fever.展开更多
This research analyzed amino acid sequence similarity between non-self T cell epitopes recognized by mouse antibodies and mouse proteins. Using sequence alignment,we found that only 8 of 1 108 epitopes are highly simi...This research analyzed amino acid sequence similarity between non-self T cell epitopes recognized by mouse antibodies and mouse proteins. Using sequence alignment,we found that only 8 of 1 108 epitopes are highly similar to mouse protein sequences. The result shows that non-self T cell epitopes are not similar or have little similarity to mouse protein sequences. Furthermore,reviewing the related literature,we also found that the eight epitopes would trigger immune responses in some particular environment,which are ignored by T cells in normal condition. The result suggests that no or low-similarity peptide vaccines can reduce the chance of collateral cross-reactions and enhance the antigen-specific immune response to vaccine.展开更多
基金Supported by China Ministry of Human Affairs and Department of Science and Technology of Shandong Province, No. 031050115
文摘AIM: To analyze the biological role of the surface antigen of Toxoplasma gondii(Tgondii) in development of vaccine. METHODS: The surface antigen of Tgondii (SAG1) was expressed in vitro. The immune response of the host to the antigen was investigated by detection of specific antibody reaction to SAG1 and production of cytokines. Mice were immunized with recombinant SAG1 and challenged with lethal strain of Tgondii RH. The monoclonal antibody to r-SAG1 was prepared and used to study the effects of SAG1 on Tgondii tachyzoites under electromicroscope. RESULTS: The mice immunized with recombinant SAG1 delayed death for 60 h compared to the control group. The recombinant SAG1 induced specific high titer of IgG and IgM antibodies as well as IFN-y, IL-2 and IL-4 cytokines in mice. In contrast, IL-12, IL-6 and TNF-α were undetectable. When T gondii tachyzoites were treated with the monoclonal antibody to r-SAG1, the parasites were gathered together, destroyed, deformed, swollen, and holes and gaps formed on the surface. CONCLUSION: SAG1 may be an excellent vaccine candidate against T gondii. The immune protection induced by SAG1 against Tgondii may be regulated by both hormone- and cell-mediated immune response.
基金This project was supported by a research grant from theNational Natural Science Foundation of China(No.399706 67)
文摘To evaluate how the efficacy of DNA inocutation affects the ability to raise protective immunity against Leptospira. [WT5”BX]Methods.[WT5”BZ] A pair of oligonucleotide primers were designed to amplify the endoflagellar gene of L. interrogans sensu stricto serovar lai. An approximately 840bp fragment was generated with PCR and inserted into VR1012, a plasmid DNA expression vector, after the fragment and VR1012 were digested respectively with EcoRV and Sal I. A recombinant plasmid designated as VR1012+flaB2 was obtained. The vector, VR1012 consits of a pUC18 backbone with the cytomegalovirus(CMV) IE1 enhancer, promoter, and intron A, transcription regulatory elements and the BGH polyadenylation sequences driving the expressing of leptospiral endoflagellar gene of L. interrogans sensu stricto serovar lai. Plasmid encoding leptospiral endoflagellin gene was injected into quadriceps of NZW rabbits. [WT5”BX]Results.[WT5”BZ]This resulted in the generation of specific leptospiral antibody with high ELISA titer (1:32768) in the rabbits. Immuno/protection was performed in guinea pigs without adjuvant. The group“VR1012+flaB2” showed higher survival rate(90%,9/10 animals),compared with the group “VR1012 lack flaB2” and the group “normal saline”. [WT5”BX]Conclusion.[WT5”BZ]The technique of DNA vaccine has potential advantages over certain other vaccine preparation technologies. However whether DNA vaccine will be useful for vaccine development remains to be tested.
文摘AIM: To detect the biological characters of the SGC7901 gastric cancer cell-dendritic cell fusion vaccines.METHODS: The suspending living SGC7901 gastric cancer cells and dendritic cells were induced to be fusioned by polyethylene glycol. Pure fusion cells were obtained by selective culture with the HAT/HT culture systems. The fusion cells were counted at different time points of culture and their growth curves were drawn to reflect their proliferative activities. The fusion cells were also cultured in culture medium to investigate whether they could grow into cell clones. MTT method was used to test the stimulating abilities of the fusion cells on T lymphocytes' proliferations. Moreover, the fusion cells were planted into nude mice to observe whether they could grow into new planted tumors in this kind of immunodeficiency animals.RESULTS: The fusion cells had weaker proliferative activity and clone abilities than their parental cells. When they were cultured, the counts of cells did not increase remarkably, nor could they grow into cell clones in culture medium. The fusion cells could not grow into new planted tumors after planted into nude mice. The stimulating abilities of the fusion cells on T lymphocytes' proliferations were remarkably increased than their parental dendritic cells. CONCLUSION: The SGC7901 gastric cancer cell-dendritic cell fusion vaccines have much weaker proliferative abilities than their parental cells, but they keep strong abilities to irritate the T lymphocytes and have no abilities to grow into new planted tumors in immunodeficiency animals. These are the biological basis for their antitumor biotherapies.
基金the China National"863"Program(Approval No.2011AA10A212)Special Fund for Agro-Scientific Research in the Public Interest(ApprovalNo.201203056)
文摘Potency is one of the most important indexes of inactivated vaccines.A number of methods have been established to assay the potency,of which the NIH test and single-dose mouse protection test are the "prescribed methods".Here,we report a method to semi-quantitatively assay the potency of an inactivated rabies vaccine,which uses fewer animals and takes less time to complete.Depending on the quality requirements of a vaccine(e.g.minimum potency),a rabies reference vaccine is,for example,diluted to the minimum potency,and 50 μL of the dilution is taken to inoculate 10 mice.The same amount of the test rabies vaccine is inoculated into another 10 mice.After two weeks,all mice are bled and serum samples are assayed for viral neutralizing antibody by the fluorescent antibody virus neutralization(FAVN) test.By comparing the median and interquartile range of antibody titers of the reference vaccine with those of the test vaccine,the test vaccine potency can be semi-quantitatively judged as to whether it is in accord with the required quality.The reliability of this method was also confirmed in dogs.The procedure can be recommended for batch potency testing during inactivated rabies vaccine production.
文摘To study the kinetics in vivo of a Hantaan virus DNA vaccine, we constructed a fusion DNA vaccine, pEGFP/S, by cloning the S segment of Hantavirus into the vector, pEGFP-C1, which encodes Green fluorescent protein EGFP. In this report, we provide evidence that pEGFP/S was distributed and persistently expressed for more than 60 days in several organs after inoculation. Our findings suggest that the persistent immune responses induced by a Hantaan virus DNA vaccine are likely due to the plasmid pEGFP/S deposited in vivo, which acts as a booster immunization.
基金Supported by the NSF of China(10371105) Supported by the Youth Science Foundation of Xinyang Normal University(20060202)
文摘A simple SI epidemic model with age of vaccination is discussed in this paper.Both vexing birth rate, the mortality rate caused by disease and vaccine waning rate areconsidered in this model. We prove that the global dynamics is completely determined bythe basic reproductive number R(ψ)(ψ denotes per capita vaccination rate). If R(0) 〈 1,the disease-free equilibrium is a global attractor; If R(ψ) 〈: 1, the disease-free equilibriumis locally asymptotically stable; If R(ψ) :〉 1, an unique endemic equilibrium exists and islocally asymptotically stable under certain condition.
文摘To evaluate maternal hepatitis B virus (HBV) DNA as risk for perinatal HBV infection among infants of HBV-infected women in California. METHODSRetrospective analysis among infants born to hepatitis B surface antigen (HBsAg)-positive mothers who received post vaccination serologic testing (PVST) between 2005 and 2011 in California. Demographic information was collected from the California Department of Public Health Perinatal Hepatitis B Program databaseand matched to birth certificate records. HBV DNA level and hepatitis B e antigen (HBeAg) status were obtained from three large commercial laboratories in California and provider records if available and matched to mother infant pairs. Univariate analysis compared infected and uninfected infants. Multivariate analysis was restricted to infected infants and controls with complete maternal HBV DNA results using a predefined high HBV DNA level of > 2 × 10<sup>7</sup> IU/mL, a 5:1 ratio of cases to controls and a two-sided confidence level of 95%. RESULTSA total of 17687 infants were born to HBsAg positive mothers in California between Jan 1 2005 and Dec 31, 2011. Among 11473 infants with PVST, only 125 (1.1%) were found to be HBV infected. Among these infected infants, lapses in Advisory Committee on Immunization Practices recommended post exposure prophylaxis (PEP) occurred in only 9 infants. However, PEP errors were not significantly different between infected and uninfected infants. Among the 347 uninfected and infected infants who had maternal HBeAg and HBV DNA level, case-control analysis found HBeAg positivity (70.4% vs 28.9%, OR = 46.76, 95%CI: 6.05-361.32, P < 0.001) and a maternal HBV DNA level ≥ 2 × 10<sup>7</sup> IU/mL (92.6% vs 18.5%, OR = 54.5, 95%CI: 12.22-247.55, P < 0.001) were associated with perinatal HBV infection. In multivariate logistic regression, maternal HBV DNA level ≥ 2 × 10<sup>7</sup> IU/mL was the only significant independent predictor of perinatal HBV infection. CONCLUSIONIn California, transmission is low and most infected infants receive appropriate PEP and vaccination. Maternal HBV DNA ≥ 2 × 10<sup>7</sup> IU/mL is associated with high risk of perinatal infection.
基金The Knowledge Innovation Program of the Chinese Academy of Sciences (KSCX2-EW-Z-3)
文摘Torque teno virus(TTV) is a nonenveloped virus containing a single-stranded,circular DNA genome of approximately 3.8kb.We completely synthesized the 3 808 nucleotides of the TTV(SANBAN isolate) genome,which contains a hairpin structure and a GC-rich region.More than 100 overlapping oligonucleotides were chemically synthesized and assembled by polymerase chain assembly reaction(PCA),and the synthesis was completed with splicing by overlap extension(SOEing).This study establishes the methodological basis of the chemical synthesis of a viral genome for use as a live attenuated vaccine or gene therapy vector.
文摘Genotyping 42 serum samples taken from the pigs in the oubreaks from 2009 to 2013 with RT-PCR and nested RT-PCR, showed more than 80% of samples were positive with Chinese PRRSV clade, and the others were European and North American classical PRRSV genotypes. Ten serum samples from unnapprent PRRS herds were examined for antibodies against PRRSV with ELISA and also for PRRSV with RT-PCR. It was clearly that the titer of antibodies against PRRSV by ELISA test could not be used for interpreting PRRSV infection. In despite of PRRS vaccination or non-vaccination, a risk of PRRSV infection and re-infection exist, utilizing RT-PCR in combination with serology will give the producer and veterinarian PRRSV more exact situation in the herds.
文摘The poliomyelitis is an acute infection produced by the polio virus that affects the human central nervous system. It is transmitted by fecal-oral and respiratory contact.There are two types of vaccine, OPV (live attenuated virus) and IPV (inactivated polio virus). Currently, there is a plan of vaccination until the age of 5 with OPV. The children vaccinated expel a virus (derived from the vaccine) to the environment, and some of the people that have oral contact with them, get vaccinated by the herd behavior. Nevertheless, taking into account the lately observed facts about the reversion to virulence of the oral polio vaccine during its circulation in the environment, a change in the current vaccination schedule is being contemplated, where the oral polio vaccine can be replaced by the inactivated vaccine. Nowadays, In Colombia the inactivated oral polio vaccine is recommended for children presenting immune deficiency who are vaccinated with IPV. These children do not expel poliovirus to the environment. This work presents a mathematical model that describes the dynamics of the infection in a population where the two types of vaccination are carried out. The population is divided into two groups of age and Michaelis-Menten interactions. Different strategies of vaccination are simulated and analyzed.
文摘Albania has been a country with a high prevalence of hepatitis B virus. Hepatitis B vaccine has been introduced nationwide in Albanian Immunization Program in 1994. Hepatitis B is given at birth, as a separate antigen, followed by three doses at 2, 4 and 6 months, where Hepatitis B, starting from 2009, is part of pentavalent vaccine of DTP-HepB-Hib. The aim of this study was to evaluate Immunization Program with Hepatitis B vaccination in order to prove program efficacy, increase public confidence in immunizations and advocate for sustainable immunization programs. Methodology was based on three components such as Immunization coverage surveys, serologic surveys and surveillance for acute cases of Hepatitis B. Results of this study showed that vaccination coverage is really high, more than 95% all over the country and with drop-out rates less than 10%. Anti-HBs levels in immunized children were very high in comparison with unimmunized ones. Incidence of HBV in children 0-14 years old is almost zero. Such results tell us that Hepatitis B vaccination is one of the most fruitful strategies for long term control of Hepatitis B disease.
文摘CpG oligodeoxynucleotides (CpG ODN) as adjuvant have been extensively studied in recent years. Phosphodiester CpG ODN (PO CpG ODN) can perfectly mimic bacterial DNA in enhancing immune response but are vulnerable to nucleases in vivo. This study aimed to evaluate the immunostimulatory potential arid safety of phosphodiester CpG ODN encapsulated in nonphospholipid liposomes. BALB/c mice were immunized intramuscularly with different formulations of liposomes, CpG ODN and hepatitis B surface antigen (HBsAg). The results demonstrated that the encapsulated PO CpG ODN were protected against rapid degradation in vivo and retained their adjuvant activity. PO CpG ODN encapsulated with HBsAg in liposomes induced strong Th1-biased or Th1/Th2 mixed humoral immune response in mice with the magnitude similar to their phosphothioate equivalent in the same formulation. High IFN-gamma production induced by this formulation confirmed the generation of strong cellular immune response. Additionally, co-delivery of HBsAg arid PO CpG ODN improved the immune response over that obtained with separate delivery. Safety experiment showed that liposome-encapsulaed PO CpG ODN and HBsAg caused mild systemic and moderate local adverse reaction. In conclusion, our data shows that PO CpG ODN encapsulated in liposomes fully exhibit their Th1-type adjuvant activity arid act as a potential adjuvant for vaccines.
文摘The Z 10 and Z 37 strains of hemorrhagic fever with renal syndrome (HFRS) virus and the Mongolian gerbil ( Merions unguiculatus ) kidney cells were used to prepare the inactivated bivalent vaccine. A phase Ⅱ clinical trial use of this vaccine was made in 750 Chinese volunteers. The results showed that the side reaction rate was 2.5% and the sero-conversion rate of neutralizing antibodies against Hantaan and Seoul viruses in the inoculated volunteers were 87.6% and 96.3% respectively.
基金supported by the National Natural Science Foundation of China(31170161)National Basic Research Program of China(2010CB530200,2010CB530205)
文摘Coxiella burnetii is the etiological agent of Q fever.To identify its major seroreactive proteins,a subgenomic protein array was developed.A total of 101 assumed virulence-associated recombinant proteins of C.burnetii were probed with sera from mice experimentally infected with C.burnetii and sera from Q fever patients.Sixteen proteins were recognized as major seroreactive antigens by the mouse sera.Seven of these 16 proteins reacted positively with at least 45% of Q fever patient sera.Notably,HspB had the highest fluorescence intensity value and positive frequency of all the proteins on the array when probed with both Q fever patient sera and mouse sera.These results suggest that these seven major seroreactive proteins,particularly HspB,are potential serodiagnostic and subunit vaccine antigens of Q fever.
基金Supported by the National Natural Science Foundation of China (90608020, 30971642)the Program for New Century Excellent Talents in University (NCET-060651)+2 种基金the National Platform Project of China (2005DKA64001)Ministry of Education of China (20050487037)the Natural Science Foundation of Hubei Province (2009CDA161)
文摘This research analyzed amino acid sequence similarity between non-self T cell epitopes recognized by mouse antibodies and mouse proteins. Using sequence alignment,we found that only 8 of 1 108 epitopes are highly similar to mouse protein sequences. The result shows that non-self T cell epitopes are not similar or have little similarity to mouse protein sequences. Furthermore,reviewing the related literature,we also found that the eight epitopes would trigger immune responses in some particular environment,which are ignored by T cells in normal condition. The result suggests that no or low-similarity peptide vaccines can reduce the chance of collateral cross-reactions and enhance the antigen-specific immune response to vaccine.