The experiment was conducted at Veterinary Research Station of Faculty of Veterinary Medicine,Royal University of Agriculture.The experimental period lasted 60 days,starting from October 1st to November 30th 2022.CRD(...The experiment was conducted at Veterinary Research Station of Faculty of Veterinary Medicine,Royal University of Agriculture.The experimental period lasted 60 days,starting from October 1st to November 30th 2022.CRD(Completely Randomized Design)was used with 2 treatments/groups,vaccination group and non-vaccination group“control”,and 6 replications.The vaccination groups received two times of vaccination by dropping into the ocular at 7 days and 21 days.Meanwhile,blood samples were collected 3 times to detect the antibody level of ND(Newcastle Disease)and contained 21 days old,35 days old and 49 days old chicks.The ELISA(Enzyme-Linked Immunosorbent Assay)was performed to detect the antibody of those 2 groups.The result of finding showed that the S/P(Sample to Positive)ratio of control at 21 days,was very low,even in 3rd quartile,which was below the threshold.However,the vaccination group was relatively high,even in 1st quartile,which was higher than the threshold.At 35 days,S/P ratio of control group was still very low,but a bit higher than at 21 days.Meanwhile,the vaccination group was still high,even in 1st quartile,and two-time higher than at 21 days,but an increasing number of samples developed less antibody than threshold,accounting for 12.22%.At 49 days,the control group was still very low,even in 3rd quartile,but a bit higher than at 21 days and 35 days,and was close to the threshold.The vaccination group was still relatively high,even in 1st quartile but lower than three times comparing to 35 days.However,in this age,the number of chickens that developed antibody seemed to be increased in the control group,vice versa for vaccination group.The average S/P ratio was different significant(p<0.001),where vaccination had higher S/P ratio than control.It was similar finding for log-titer,the vaccination had higher figure(p<0.001).The risk of infection of ND was higher in control group,but it will reduce by increasing the age of chicken,while vaccination group was decreased by increasing age,especially at 4展开更多
Respiratory syncytial virus （RSV） is the leading cause of pneumonia and bronchiolitis in infants and is the most frequent cause of lower respiratory tract infections in children. Efficacious vaccination has been a l...Respiratory syncytial virus （RSV） is the leading cause of pneumonia and bronchiolitis in infants and is the most frequent cause of lower respiratory tract infections in children. Efficacious vaccination has been a longstanding goal in neonates. Due to immaturity of the neonatal immune system, vaccination has shown limited success in stimulating the neonatal endogenous immune system. Advances in the understanding of neonatal immunology have resulted in renewed development of neonatal vaccination. In this article, we review recent advances in neonatal anti- RSV vaccination strategies, including active and passive vaccination approaches, with emphasis on the effect of maternal neutralizing antibody and the role of maternal antibody in neonatal immune modulations. Recent reports in a variety of antiviral vaccine animal models have shown that maternal antibody, different from conventional vaccination, plays an immune modulatory role in the newborn immune system. Active immunization of the pregnant mother and the offspring can effectively stimulate and maintain potent neonatal immune responses, including an endogenous cytotoxic response and neutralizing antibody generation. The induced newborn endogenous antiviral immunity can last up to 6 months, and effectively blunt viral replication. Immune complexes, formed from the integral binding of the maternal neutralizing antibody and viral vaccine antigen, may play an important role in the maternal antibody-mediated neonatal immune response. The underlying mechanisms and future perspectives are discussed.展开更多
Background: the hepatitis B virus infection remains a major public health problem worldwide. It can lead to a liver cirrhosis and/or hepatocellular carcinoma. The World Health Organisation (WHO) has recommended the im...Background: the hepatitis B virus infection remains a major public health problem worldwide. It can lead to a liver cirrhosis and/or hepatocellular carcinoma. The World Health Organisation (WHO) has recommended the implementation of generalised vaccination programs against hepatitis B. In Cameroon, this vaccine was introduced in the expanded program on immunization (EPI) in 2005, but few studies have assessed the immune response. Objective: the general objective of this study was to identify factors associated with antibody levels among children aged from 15 to 59 months vaccinated against hepatitis B during the EPI in Cameroon. Method: this was a cross-sectional study carried out from December 2021 to June 2022 in a paediatric centre of Yaoundé (Cameroon). We analysed the antibody level in children vaccinated against hepatitis B within the framework of the EPI. We enrolled children who had received a series of 3 intramuscular doses of hepatitis B vaccine at 6, 10 and 14 weeks after birth. Some children could receive a 4<sup>th</sup> booster dose between 12 months. The antibody level was assessed by measuring the anti-HBs in such children, aged 15 - 59 months. A good immunization was defined as a serum level of anti-HBs antibody level above 100 IU/mL;a poor immunization, for an anti-HBs antibody level between 10 and 100 IU/mL;and a non-immunization, for an anti-HBs antibody level < 10 IU/mL. Association between explored factors and poor or non-immunization was evaluated through the Chi square test. The significance threshold was defined at p < 0.05. Results: sixty subjects were included in the study with a slight female majority: 31 cases (52%). The average age was 38.5 ± 15.7 months (range 15 - 59 months). We found 32 (53%) cases of good immunization;21 (35%) of poor immunization;and 7 children (12%) with a non-immunization. The only factor associated with poor or non-immunization was the age between 37 - 59 months (p = 0.016). Conclusion: Anti HBs Antibody levels in children vaccinated against hepatitis B vir展开更多
文摘The experiment was conducted at Veterinary Research Station of Faculty of Veterinary Medicine,Royal University of Agriculture.The experimental period lasted 60 days,starting from October 1st to November 30th 2022.CRD(Completely Randomized Design)was used with 2 treatments/groups,vaccination group and non-vaccination group“control”,and 6 replications.The vaccination groups received two times of vaccination by dropping into the ocular at 7 days and 21 days.Meanwhile,blood samples were collected 3 times to detect the antibody level of ND(Newcastle Disease)and contained 21 days old,35 days old and 49 days old chicks.The ELISA(Enzyme-Linked Immunosorbent Assay)was performed to detect the antibody of those 2 groups.The result of finding showed that the S/P(Sample to Positive)ratio of control at 21 days,was very low,even in 3rd quartile,which was below the threshold.However,the vaccination group was relatively high,even in 1st quartile,which was higher than the threshold.At 35 days,S/P ratio of control group was still very low,but a bit higher than at 21 days.Meanwhile,the vaccination group was still high,even in 1st quartile,and two-time higher than at 21 days,but an increasing number of samples developed less antibody than threshold,accounting for 12.22%.At 49 days,the control group was still very low,even in 3rd quartile,but a bit higher than at 21 days and 35 days,and was close to the threshold.The vaccination group was still relatively high,even in 1st quartile but lower than three times comparing to 35 days.However,in this age,the number of chickens that developed antibody seemed to be increased in the control group,vice versa for vaccination group.The average S/P ratio was different significant(p<0.001),where vaccination had higher S/P ratio than control.It was similar finding for log-titer,the vaccination had higher figure(p<0.001).The risk of infection of ND was higher in control group,but it will reduce by increasing the age of chicken,while vaccination group was decreased by increasing age,especially at 4
文摘Respiratory syncytial virus （RSV） is the leading cause of pneumonia and bronchiolitis in infants and is the most frequent cause of lower respiratory tract infections in children. Efficacious vaccination has been a longstanding goal in neonates. Due to immaturity of the neonatal immune system, vaccination has shown limited success in stimulating the neonatal endogenous immune system. Advances in the understanding of neonatal immunology have resulted in renewed development of neonatal vaccination. In this article, we review recent advances in neonatal anti- RSV vaccination strategies, including active and passive vaccination approaches, with emphasis on the effect of maternal neutralizing antibody and the role of maternal antibody in neonatal immune modulations. Recent reports in a variety of antiviral vaccine animal models have shown that maternal antibody, different from conventional vaccination, plays an immune modulatory role in the newborn immune system. Active immunization of the pregnant mother and the offspring can effectively stimulate and maintain potent neonatal immune responses, including an endogenous cytotoxic response and neutralizing antibody generation. The induced newborn endogenous antiviral immunity can last up to 6 months, and effectively blunt viral replication. Immune complexes, formed from the integral binding of the maternal neutralizing antibody and viral vaccine antigen, may play an important role in the maternal antibody-mediated neonatal immune response. The underlying mechanisms and future perspectives are discussed.
文摘Background: the hepatitis B virus infection remains a major public health problem worldwide. It can lead to a liver cirrhosis and/or hepatocellular carcinoma. The World Health Organisation (WHO) has recommended the implementation of generalised vaccination programs against hepatitis B. In Cameroon, this vaccine was introduced in the expanded program on immunization (EPI) in 2005, but few studies have assessed the immune response. Objective: the general objective of this study was to identify factors associated with antibody levels among children aged from 15 to 59 months vaccinated against hepatitis B during the EPI in Cameroon. Method: this was a cross-sectional study carried out from December 2021 to June 2022 in a paediatric centre of Yaoundé (Cameroon). We analysed the antibody level in children vaccinated against hepatitis B within the framework of the EPI. We enrolled children who had received a series of 3 intramuscular doses of hepatitis B vaccine at 6, 10 and 14 weeks after birth. Some children could receive a 4<sup>th</sup> booster dose between 12 months. The antibody level was assessed by measuring the anti-HBs in such children, aged 15 - 59 months. A good immunization was defined as a serum level of anti-HBs antibody level above 100 IU/mL;a poor immunization, for an anti-HBs antibody level between 10 and 100 IU/mL;and a non-immunization, for an anti-HBs antibody level < 10 IU/mL. Association between explored factors and poor or non-immunization was evaluated through the Chi square test. The significance threshold was defined at p < 0.05. Results: sixty subjects were included in the study with a slight female majority: 31 cases (52%). The average age was 38.5 ± 15.7 months (range 15 - 59 months). We found 32 (53%) cases of good immunization;21 (35%) of poor immunization;and 7 children (12%) with a non-immunization. The only factor associated with poor or non-immunization was the age between 37 - 59 months (p = 0.016). Conclusion: Anti HBs Antibody levels in children vaccinated against hepatitis B vir
