The primary objective of this study was to evaluation the immune efficacy of native inactivated vaccine against porcine reproductive and respiratory syndrome virus. The experimental design included 60 gilts and 9 boar...The primary objective of this study was to evaluation the immune efficacy of native inactivated vaccine against porcine reproductive and respiratory syndrome virus. The experimental design included 60 gilts and 9 boars equal distribution in two farms free of antibody for PRRSV at the beginning of the experiment for two consecutive months. These gilts and boars were randomly assigned to three treatment groups equally designated as groupsⅠ～Ⅲ. GroupⅠwas inoculated intramuscularly with RespPRRSV/Repro vaccine. Group Ⅱ was inoculated intramuscularly with native multivalent inactivated vaccine. Group Ⅲ was sham-inoculated intramuscularly with saline as control. Gilts and boars were inoculated again at six months intervals during the consecutive 2 years. The neonatal piglets of three groups were inoculated the same vaccine as their parents one week before weaning (piglets were 25 days). Then antibody anti-PRRSV was detected in sera obtained from gilts, boars and piglets. Biological tissue samples were collected from the recently deceased or sacrificed pigs which presented with similar PRRS symptoms. Virus isolation and viral RNA using RT-nPCR were carried through in collected tissue samples, sera and semen. Productive performances of pigs were also evaluated in this project. The results showed all the indexes in groupⅡwere very similar to that of groupⅠexcept the virus isolation and viral RNA detection. Control group had more virus isolates and viral RNA detection than inoculated groups. The rate of piglets surviving, born dead and postnatal deaths and fattening differed significantly (P<(0.05)) between experiment groups and control. This was implied that pigs inoculated with native inactivated vaccine had the similarity immune efficacy to that of pigs inoculated attenuated vaccine. This is the first large-scale to evaluation the immune efficacy of native multivalent inactivated vaccine against PRRSV in field trial. Inoculating native inactivated multivalent vaccine is also an effective measure to prevent PRRS in Shanghai pig farms and this can reduce the risk of vaccine virus shedding because of inoculating the attenuated vaccine.展开更多
AIM:To investigate the protective efficacy of H2 strain attenuated live hepatitis A vaccines (H2-strain vaccines) in hepatitis A (HA) outbreaks.METHODS:With the permission of their parents, 5551 pre-school and grade 1...AIM:To investigate the protective efficacy of H2 strain attenuated live hepatitis A vaccines (H2-strain vaccines) in hepatitis A (HA) outbreaks.METHODS:With the permission of their parents, 5551 pre-school and grade 1-3 primary school children were inoculated with 1 dose (10(6.5) TCID(50)) of H2 strain vaccines in a nonrandomized, controlled trial conducted in Fucheng County, Hebei Province in May 1997.Another 6485 children in the same grades and compatible in gender and age were enrolled as controls. Epidemiological and serological survey was conducted to evaluate the protective efficacy of the vaccines. ELISA was used to detect serum IgM anti-HAV.RESULTS:HA outbreak started in early May 1998, peaked in the middle of the same month, and lasted about 80 days. Overall 302 HA cases were found, 192(63.58%) were 5-9 years old. One vaccinee and 25 control cases were found to have hepatitis A, which account for 0.28% (1/356) and 5.92% (25/422) of all vaccinees and controls in the 14 villages, respectively. The protective efficacy of vaccines was 95.27% (95% CI: 85.83%-104.72%). In subjects tested for anti-HAV IgM from 13 villages, 1(0.40%) overt and 11(4.06%) asymptomatic HAV cases were found in 271 vaccinees but 21(6.69%) of overt and asymptomatic ones were found in 314 controls.CONCLUSION:H2 strain vaccines were excellent in preventing overt hepatitis A,but not so effective in preventing asymptomatic hepatitis A virus infection.A booster dose might be needed to get permanent reliable immunity.展开更多
为建立禽腺病毒4型的禽源细胞感染模型,并考察细胞培养毒株对动物的致病性,将实验室2014-2017年间分离的5株血清4型禽腺病毒接种鸡肝癌细胞(leghorn male hepatocellular cells,LMH)并盲传,选取各病毒的LMH细胞培养物,按一定剂量经腿部...为建立禽腺病毒4型的禽源细胞感染模型,并考察细胞培养毒株对动物的致病性,将实验室2014-2017年间分离的5株血清4型禽腺病毒接种鸡肝癌细胞(leghorn male hepatocellular cells,LMH)并盲传,选取各病毒的LMH细胞培养物,按一定剂量经腿部肌肉注射接种4周龄SPF鸡;记录试验动物的发病情况,剖检采集发病或死亡鸡的脏器并制作病理切片,观察并分析病毒细胞培养物感染SPF鸡的组织病理变化。结果发现:5株血清4型禽腺病毒在LMH细胞上盲传至第4代时开始出现I群禽腺病毒所致的特异性细胞病变,提取培养物中病毒核酸并进行PCR鉴定,均能扩增出大小约564 bp的特异性扩增片段,表明病毒能在LMH细胞上稳定增殖。选取各病毒第10代细胞培养物进行SPF鸡回归试验,发现细胞培养上清接种4周龄SPF鸡后第3天开始,有部分鸡开始精神沉郁,食欲消退、卧地不起瘫痪并迅速死亡,病理剖检及病理组织切片结果显示HB-1、HB-2、HB-3和SD-1毒株保持对4周龄SPF鸡的致病性,病死鸡中能观察到典型的组织病理学变化,而对照组不出现任何临床症状及病理变化。以上结果表明,LMH细胞可用于禽腺病毒增殖传代,是开展禽腺病毒分子致病机制研究的理想细胞模型。展开更多
文摘The primary objective of this study was to evaluation the immune efficacy of native inactivated vaccine against porcine reproductive and respiratory syndrome virus. The experimental design included 60 gilts and 9 boars equal distribution in two farms free of antibody for PRRSV at the beginning of the experiment for two consecutive months. These gilts and boars were randomly assigned to three treatment groups equally designated as groupsⅠ～Ⅲ. GroupⅠwas inoculated intramuscularly with RespPRRSV/Repro vaccine. Group Ⅱ was inoculated intramuscularly with native multivalent inactivated vaccine. Group Ⅲ was sham-inoculated intramuscularly with saline as control. Gilts and boars were inoculated again at six months intervals during the consecutive 2 years. The neonatal piglets of three groups were inoculated the same vaccine as their parents one week before weaning (piglets were 25 days). Then antibody anti-PRRSV was detected in sera obtained from gilts, boars and piglets. Biological tissue samples were collected from the recently deceased or sacrificed pigs which presented with similar PRRS symptoms. Virus isolation and viral RNA using RT-nPCR were carried through in collected tissue samples, sera and semen. Productive performances of pigs were also evaluated in this project. The results showed all the indexes in groupⅡwere very similar to that of groupⅠexcept the virus isolation and viral RNA detection. Control group had more virus isolates and viral RNA detection than inoculated groups. The rate of piglets surviving, born dead and postnatal deaths and fattening differed significantly (P<(0.05)) between experiment groups and control. This was implied that pigs inoculated with native inactivated vaccine had the similarity immune efficacy to that of pigs inoculated attenuated vaccine. This is the first large-scale to evaluation the immune efficacy of native multivalent inactivated vaccine against PRRSV in field trial. Inoculating native inactivated multivalent vaccine is also an effective measure to prevent PRRS in Shanghai pig farms and this can reduce the risk of vaccine virus shedding because of inoculating the attenuated vaccine.
基金national ninth five-year study program for tackling key scientific problems,No.03-01-01
文摘AIM:To investigate the protective efficacy of H2 strain attenuated live hepatitis A vaccines (H2-strain vaccines) in hepatitis A (HA) outbreaks.METHODS:With the permission of their parents, 5551 pre-school and grade 1-3 primary school children were inoculated with 1 dose (10(6.5) TCID(50)) of H2 strain vaccines in a nonrandomized, controlled trial conducted in Fucheng County, Hebei Province in May 1997.Another 6485 children in the same grades and compatible in gender and age were enrolled as controls. Epidemiological and serological survey was conducted to evaluate the protective efficacy of the vaccines. ELISA was used to detect serum IgM anti-HAV.RESULTS:HA outbreak started in early May 1998, peaked in the middle of the same month, and lasted about 80 days. Overall 302 HA cases were found, 192(63.58%) were 5-9 years old. One vaccinee and 25 control cases were found to have hepatitis A, which account for 0.28% (1/356) and 5.92% (25/422) of all vaccinees and controls in the 14 villages, respectively. The protective efficacy of vaccines was 95.27% (95% CI: 85.83%-104.72%). In subjects tested for anti-HAV IgM from 13 villages, 1(0.40%) overt and 11(4.06%) asymptomatic HAV cases were found in 271 vaccinees but 21(6.69%) of overt and asymptomatic ones were found in 314 controls.CONCLUSION:H2 strain vaccines were excellent in preventing overt hepatitis A,but not so effective in preventing asymptomatic hepatitis A virus infection.A booster dose might be needed to get permanent reliable immunity.
文摘为建立禽腺病毒4型的禽源细胞感染模型,并考察细胞培养毒株对动物的致病性,将实验室2014-2017年间分离的5株血清4型禽腺病毒接种鸡肝癌细胞(leghorn male hepatocellular cells,LMH)并盲传,选取各病毒的LMH细胞培养物,按一定剂量经腿部肌肉注射接种4周龄SPF鸡;记录试验动物的发病情况,剖检采集发病或死亡鸡的脏器并制作病理切片,观察并分析病毒细胞培养物感染SPF鸡的组织病理变化。结果发现:5株血清4型禽腺病毒在LMH细胞上盲传至第4代时开始出现I群禽腺病毒所致的特异性细胞病变,提取培养物中病毒核酸并进行PCR鉴定,均能扩增出大小约564 bp的特异性扩增片段,表明病毒能在LMH细胞上稳定增殖。选取各病毒第10代细胞培养物进行SPF鸡回归试验,发现细胞培养上清接种4周龄SPF鸡后第3天开始,有部分鸡开始精神沉郁,食欲消退、卧地不起瘫痪并迅速死亡,病理剖检及病理组织切片结果显示HB-1、HB-2、HB-3和SD-1毒株保持对4周龄SPF鸡的致病性,病死鸡中能观察到典型的组织病理学变化,而对照组不出现任何临床症状及病理变化。以上结果表明,LMH细胞可用于禽腺病毒增殖传代,是开展禽腺病毒分子致病机制研究的理想细胞模型。
