The Experts below are selected from a list of 1578 Experts worldwide ranked by ideXlab platform
Peter Mcintyre - One of the best experts on this subject based on the ideXlab platform.
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immunogenicity and safety of monovalent acellular pertussis vaccine at birth a randomized clinical trial
JAMA Pediatrics, 2018Co-Authors: Helen Marshall, Peter Mcintyre, Nicholas Wood, Terry Nolan, Peter Richmond, Emma Gibbs, Kirsten P PerrettAbstract:Importance An alternative option to maternal vaccination to prevent severe pertussis in infants is vaccination at birth. Data are needed on the immunogenicity and safety of a birth dose of monovalent acellular pertussis (aP) vaccine. Objective To compare IgG antibody responses to vaccine antigens at 6, 10, 24, and 32 weeks of age between newborn infants receiving the aP vaccine and hepatitis B vaccine (HBV) or HBV alone. Design, Setting, and Participants A randomized clinical trial was conducted at 4 sites in Australia (Sydney, Melbourne, Adelaide, and Perth) between June 11, 2010, and March 14, 2013, among 440 healthy term (>36 weeks’ gestation) infants aged less than 5 days at recruitment. Statistical analysis was performed from March 1, 2015, to June 2, 2016. Intervention Newborns received HBV and, after stratification by maternal receipt of adult-formulated aP-containing vaccine (tetanus toxoid, reduced diphtheria toxoid, and pertussis antigen content [Tdap]) prior to pregnancy, were block randomized to receive the aP vaccine (without diphtheria or tetanus) within 5 days of birth or not. At 6, 16, and 24 weeks, infants received a hexavalent vaccine with pediatric-formulated diphtheria, tetanus and pertussis antigens (DTaP),Haemophilus influenzaetype b (Hib), HBV, and polio vaccine, as well as the 10-valent pneumococcal conjugate vaccine. Main Outcomes and Measures Detectable (>5 enzyme-linked immunosorbent assay units per milliliter) and geometric mean concentrations of IgG antibody to pertussis toxin (PT), Pertactin, and filamentous hemagglutinin at 6, 10, and 24 weeks stratified by maternal Tdap history, and antibody at 32 weeks to HBV, Hib, polio, diphtheria, tetanus, and pneumococcal serotypes. The primary outcome was detectable IgG to both PT and Pertactin at 10 weeks. Results A total of 440 infants (207 girls and 233 boys; median gestation, 39.2 weeks) were randomized to receive the aP vaccine plus HBV (n = 221) or HBV only (control group; n = 219). At 10 weeks, 192 of 206 infants who received the aP vaccine (93.2%) had detectable antibodies to both PT and Pertactin vs 98 of 193 infants in the control group (50.8%) (P Conclusions and Relevance The monovalent aP vaccine is immunogenic and safe in neonates and, if licensed and available, would be valuable for newborns whose mothers did not receive the Tdap vaccine during pregnancy. Trial Registration http://anzctr.org.auIdentifier:ACTRN12609000905268
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Pertactin negative bordetella pertussis demonstrates higher fitness under vaccine selection pressure in a mixed infection model
Vaccine, 2015Co-Authors: Azadeh Safarchi, Helen Marshall, Peter Mcintyre, Sophie Octavia, Laurence Don Wai Luu, Chin Yen Tay, Vitali Sintchenko, Nicholas Wood, Ruiting LanAbstract:Whooping cough or pertussis is a highly infectious respiratory disease in humans caused by Bordetella pertussis. The use of acellular vaccines (ACV) has been associated with the recent resurgence of pertussis in developed countries including Australia despite high vaccination coverage where B. pertussis strains that do not express Pertactin (Prn), a key antigenic component of the ACV, have emerged and become prevalent. In this study, we used an in vivo competition assay in mice immunised with ACV and in naive (control) mice to compare the proportion of colonisation with recent clinical Prn positive and Prn negative B. pertussis strains from Australia. The Prn negative strain colonised the respiratory tract more effectively than the Prn positive strain in immunised mice, out-competing the Prn positive strain by day 3 of infection. However, in control mice, the Prn positive strain out-competed the Prn negative strain. Our findings of greater ability of Prn negative strains to colonise ACV-immunised mice are consistent with reports of selective advantage for these strains in ACV-immunised humans.
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rapid increase in Pertactin deficient bordetella pertussis isolates australia
Emerging Infectious Diseases, 2014Co-Authors: Connie Lam, Helen Marshall, Peter Mcintyre, Nicole Guiso, Sophie Octavia, Vitali Sintchenko, Lawrence Ricafort, Gwendolyn L Gilbert, Nicholas Wood, Anthony D. KeilAbstract:Acellular vaccines against Bordetella pertussis were introduced in Australia in 1997. By 2000, these vaccines had replaced whole-cell vaccines. During 2008–2012, a large outbreak of pertussis occurred. During this period, 30% (96/320) of B. pertussis isolates did not express the vaccine antigen Pertactin (Prn). Multiple mechanisms of Prn inactivation were documented, including IS481 and IS1002 disruptions, a variation within a homopolymeric tract, and deletion of the prn gene. The mechanism of lack of expression of Prn in 16 (17%) isolates could not be determined at the sequence level. These findings suggest that B. pertussis not expressing Prn arose independently multiple times since 2008, rather than by expansion of a single Prnnegative clone. All but 1 isolate had ptxA1, prn2, and ptxP3, the alleles representative of currently circulating strains in Australia. This pattern is consistent with continuing evolution of B. pertussis in response to vaccine selection pressure.
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primary and booster immunization with a diphtheria tetanus acellular pertussis hepatitis b dtpa hbv and haemophilus influenzae type b hib vaccine administered separately or together is safe and immunogenic
International Journal of Infectious Diseases, 2010Co-Authors: Helen Marshall, Peter Mcintyre, Don Roberton, Leonie Dinan, Karin HardtAbstract:Summary Objectives The aim of this study was to evaluate the safety and immunogenicity of DTPa–HBV and Hib vaccines given mixed or separately to 360 healthy infants at 2, 4, and 6 months of age. Methods Immune memory was assessed in lower responders (post-primary anti-PRP Results One month after primary vaccination, 98% had seroprotective antibody levels against HBV and 94–97% against Hib (anti-PRP≥0.15μg/ml). A statistically significant difference between groups was observed in the proportion of subjects who achieved anti-PRP antibodies ≥1.0μg/ml post-primary vaccination; 68.1% for DTPa–HBV/Hib and 84.5% for DTPa–HBV and Hib. PRP administered to lower responders produced a 7-fold increase in anti-PRP antibodies, indicative of immunological memory. After DTPa–HBV/Hib booster vaccination, 96–100% of subjects had seroprotective antibody concentrations against Hib, hepatitis B, tetanus, and diphtheria and high vaccine response rates against pertussis toxoid, filamentous hemagglutinin, and Pertactin. Conclusion A robust and protective Hib response was demonstrated following plain PRP and/or a booster conjugate Hib vaccine in both lower and higher Hib responders.
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high levels of antibody in adults three years after vaccination with a reduced antigen content diphtheria tetanus acellular pertussis vaccine
Vaccine, 2004Co-Authors: Peter Mcintyre, Joanne Wolter, Margaret A Burgess, Fiona Turnbull, Annemarie Egan, Lode SchuermanAbstract:There is increasing interest in prevention of pertussis in adults by vaccination, but little is known about the duration of the antibody response to pertussis, diphtheria or tetanus in reduced antigen content vaccines formulated for adult use. Follow-up of a clinical trial including 550 adults comparing responses to reduced antigen content diphtheria-tetanus-acellular pertussis (dTpa) vaccine, or a licensed Td vaccine, provided the opportunity to evaluate this. Blood samples were collected at 0, 1, 12, 24 and 36 months following vaccination; of the original cohort of 550, 387 subjects (dTpa group N = 310, Td + pa group N = 77) were tested at month 36. Following a decrease in antibody levels against all vaccine antigens between one and 24 months following vaccination, levels stabilized during the third year, remaining higher at 36 months than pre-vaccination for all vaccine antigens. In particular, more than 90% of subjects remained seropositive for pertussis toxin and Pertactin antibodies at 36 months after vaccination, suggesting ongoing protection against pertussis. Adult-formulated dTpa vaccines could replace Td for routine booster vaccination of older individuals.
Nicole Guiso - One of the best experts on this subject based on the ideXlab platform.
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Pertactin-Negative and Filamentous Hemagglutinin-Negative Bordetella pertussis, Australia, 2013–2017
'Centers for Disease Control and Prevention (CDC)', 2019Co-Authors: Sophie Octavia, Nicole Guiso, Laurence Don Wai Luu, Michael Payne, Verlaine Timms, Chin Yen Tay, Anthony D. Keil, Vitali Sintchenko, Ruiting LanAbstract:During the 2008–2012 pertussis epidemic in Australia, Pertactin (Prn)–negative Bordetella pertussis emerged. We analyzed 78 isolates from the 2013–2017 epidemic and documented continued expansion of Prn-negative ptxP3 B. pertussis strains. We also detected a filamentous hemagglutinin-negative and Prn-negative B. pertussis isolate
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analysis of bordetella pertussis clinical isolates circulating in european countries during the period 1998 2012
European Journal of Clinical Microbiology & Infectious Diseases, 2015Co-Authors: M Van Gent, Nicole Guiso, Hans O Hallander, C J Heuvelman, H G J Van Der Heide, Abdolreza Advani, C Wirsing H Von Kőnig, Didrik F Vestrheim, Tine Dalby, Norman K FryAbstract:Despite more than 50 years of vaccination, pertussis is still an endemic disease, with regular epidemic outbreaks. With the exception of Poland, European countries have replaced whole-cell vaccines (WCVs) by acellular vaccines (ACVs) in the 1990s. Worldwide, antigenic divergence in vaccine antigens has been found between vaccine strains and circulating strains. In this work, 466 Bordetella pertussis isolates collected in the period 1998–2012 from 13 European countries were characterised by multi-locus antigen sequence typing (MAST) of the pertussis toxin promoter (ptxP) and of the genes coding for proteins used in the ACVs: pertussis toxin (Ptx), Pertactin (Prn), type 2 fimbriae (Fim2) and type 3 fimbriae (Fim3). Isolates were further characterised by fimbrial serotyping, multi-locus variable-number tandem repeat analysis (MLVA) and pulsed-field gel electrophoresis (PFGE). The results showed a very similar B. pertussis population for 12 countries using ACVs, while Poland, which uses a WCV, was quite distinct, suggesting that ACVs and WCVs select for different B. pertussis populations. This study forms a baseline for future studies on the effect of vaccination programmes on B. pertussis populations.
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Pertactin deficient bordetella pertussis present a better fitness in mice immunized with an acellular pertussis vaccine
Vaccine, 2014Co-Authors: Nicolas Hegerle, Nicole Guiso, G DoreAbstract:Bordetella pertussis is the etiologic agent of whooping cough and has been the target of vaccination for over fifty years. The latest strategies include the use of acellular pertussis vaccines that induce specific immunity against few virulence factors amongst which Pertactin is included in three and five component acellular pertussis vaccines. Recently, it has been reported that B. pertussis clinical isolates loose the production of this adhesin in regions reaching high vaccine coverage with vaccines targeting this virulence factor. We here demonstrate that isolates not producing Pertactin are capable of sustaining longer infection as compared to Pertactin producing isolates in an in vivo model of acellular pertussis immunization. Loosing Pertactin production might thus provide a selective advantage to these isolates in this background, which could account for the upraise in prevalence of these Pertactin deficient isolates in the population.
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rapid increase in Pertactin deficient bordetella pertussis isolates australia
Emerging Infectious Diseases, 2014Co-Authors: Connie Lam, Helen Marshall, Peter Mcintyre, Nicole Guiso, Sophie Octavia, Vitali Sintchenko, Lawrence Ricafort, Gwendolyn L Gilbert, Nicholas Wood, Anthony D. KeilAbstract:Acellular vaccines against Bordetella pertussis were introduced in Australia in 1997. By 2000, these vaccines had replaced whole-cell vaccines. During 2008–2012, a large outbreak of pertussis occurred. During this period, 30% (96/320) of B. pertussis isolates did not express the vaccine antigen Pertactin (Prn). Multiple mechanisms of Prn inactivation were documented, including IS481 and IS1002 disruptions, a variation within a homopolymeric tract, and deletion of the prn gene. The mechanism of lack of expression of Prn in 16 (17%) isolates could not be determined at the sequence level. These findings suggest that B. pertussis not expressing Prn arose independently multiple times since 2008, rather than by expansion of a single Prnnegative clone. All but 1 isolate had ptxA1, prn2, and ptxP3, the alleles representative of currently circulating strains in Australia. This pattern is consistent with continuing evolution of B. pertussis in response to vaccine selection pressure.
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virulence of Pertactin negative bordetella pertussis isolates from infants france
Emerging Infectious Diseases, 2013Co-Authors: Helene Bodilis, Nicole GuisoAbstract:Bordetella pertussis isolates that do not express Pertactin (PRN) are increasing in regions where acellular pertussis vaccines have been used for >7 years. We analyzed data from France and compared clinical symptoms among infants <6 months old infected by PRN-positive or PRN-negative isolates. No major clinical differences were found between the 2 groups.
Margaret A Burgess - One of the best experts on this subject based on the ideXlab platform.
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high levels of antibody in adults three years after vaccination with a reduced antigen content diphtheria tetanus acellular pertussis vaccine
Vaccine, 2004Co-Authors: Peter Mcintyre, Joanne Wolter, Margaret A Burgess, Fiona Turnbull, Annemarie Egan, Lode SchuermanAbstract:There is increasing interest in prevention of pertussis in adults by vaccination, but little is known about the duration of the antibody response to pertussis, diphtheria or tetanus in reduced antigen content vaccines formulated for adult use. Follow-up of a clinical trial including 550 adults comparing responses to reduced antigen content diphtheria-tetanus-acellular pertussis (dTpa) vaccine, or a licensed Td vaccine, provided the opportunity to evaluate this. Blood samples were collected at 0, 1, 12, 24 and 36 months following vaccination; of the original cohort of 550, 387 subjects (dTpa group N = 310, Td + pa group N = 77) were tested at month 36. Following a decrease in antibody levels against all vaccine antigens between one and 24 months following vaccination, levels stabilized during the third year, remaining higher at 36 months than pre-vaccination for all vaccine antigens. In particular, more than 90% of subjects remained seropositive for pertussis toxin and Pertactin antibodies at 36 months after vaccination, suggesting ongoing protection against pertussis. Adult-formulated dTpa vaccines could replace Td for routine booster vaccination of older individuals.
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immunogenicity of a combined diphtheria tetanus acellular pertussis vaccine in adults
Vaccine, 2004Co-Authors: Pierre Van Damme, Margaret A BurgessAbstract:Two clinical studies were undertaken to evaluate the immunogenicity of an adult-type dTpa booster vaccine (Boostrix by GlaxoSmithKline Biologicals). Blood samples taken prior to vaccination showed that 24.4 and 13.0% of subjects were seronegative for diphtheria and tetanus antibodies, respectively. Moreover, about one-third of the vaccinees had no detectable levels of antibodies to pertussis toxoid (PT) or Pertactin (PRN). One month post-vaccination, more than 93% of all individuals, regardless of age or type of vaccine received, had seroprotective antibody levels for diphtheria and tetanus (> or = 0.1IU/ml). In those individuals vaccinated with the adult-type dTpa vaccine (Boostrix), more than 98% were found to be seropositive for antibodies to all three pertussis antigens (PT, filamentous haemogluttin (FHA), and PRN). These data suggest that immunity to diphtheria, tetanus and pertussis (DTP) in adults wanes and that booster vaccination with an adult-type combined dTpa vaccine would boost the serological response to diphtheria antitoxin, tetanus antitoxin and antibodies to Bordetella pertussis PT, FHA and PRN.
Lode Schuerman - One of the best experts on this subject based on the ideXlab platform.
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high levels of antibody in adults three years after vaccination with a reduced antigen content diphtheria tetanus acellular pertussis vaccine
Vaccine, 2004Co-Authors: Peter Mcintyre, Joanne Wolter, Margaret A Burgess, Fiona Turnbull, Annemarie Egan, Lode SchuermanAbstract:There is increasing interest in prevention of pertussis in adults by vaccination, but little is known about the duration of the antibody response to pertussis, diphtheria or tetanus in reduced antigen content vaccines formulated for adult use. Follow-up of a clinical trial including 550 adults comparing responses to reduced antigen content diphtheria-tetanus-acellular pertussis (dTpa) vaccine, or a licensed Td vaccine, provided the opportunity to evaluate this. Blood samples were collected at 0, 1, 12, 24 and 36 months following vaccination; of the original cohort of 550, 387 subjects (dTpa group N = 310, Td + pa group N = 77) were tested at month 36. Following a decrease in antibody levels against all vaccine antigens between one and 24 months following vaccination, levels stabilized during the third year, remaining higher at 36 months than pre-vaccination for all vaccine antigens. In particular, more than 90% of subjects remained seropositive for pertussis toxin and Pertactin antibodies at 36 months after vaccination, suggesting ongoing protection against pertussis. Adult-formulated dTpa vaccines could replace Td for routine booster vaccination of older individuals.
Nicholas Wood - One of the best experts on this subject based on the ideXlab platform.
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immunogenicity and safety of monovalent acellular pertussis vaccine at birth a randomized clinical trial
JAMA Pediatrics, 2018Co-Authors: Helen Marshall, Peter Mcintyre, Nicholas Wood, Terry Nolan, Peter Richmond, Emma Gibbs, Kirsten P PerrettAbstract:Importance An alternative option to maternal vaccination to prevent severe pertussis in infants is vaccination at birth. Data are needed on the immunogenicity and safety of a birth dose of monovalent acellular pertussis (aP) vaccine. Objective To compare IgG antibody responses to vaccine antigens at 6, 10, 24, and 32 weeks of age between newborn infants receiving the aP vaccine and hepatitis B vaccine (HBV) or HBV alone. Design, Setting, and Participants A randomized clinical trial was conducted at 4 sites in Australia (Sydney, Melbourne, Adelaide, and Perth) between June 11, 2010, and March 14, 2013, among 440 healthy term (>36 weeks’ gestation) infants aged less than 5 days at recruitment. Statistical analysis was performed from March 1, 2015, to June 2, 2016. Intervention Newborns received HBV and, after stratification by maternal receipt of adult-formulated aP-containing vaccine (tetanus toxoid, reduced diphtheria toxoid, and pertussis antigen content [Tdap]) prior to pregnancy, were block randomized to receive the aP vaccine (without diphtheria or tetanus) within 5 days of birth or not. At 6, 16, and 24 weeks, infants received a hexavalent vaccine with pediatric-formulated diphtheria, tetanus and pertussis antigens (DTaP),Haemophilus influenzaetype b (Hib), HBV, and polio vaccine, as well as the 10-valent pneumococcal conjugate vaccine. Main Outcomes and Measures Detectable (>5 enzyme-linked immunosorbent assay units per milliliter) and geometric mean concentrations of IgG antibody to pertussis toxin (PT), Pertactin, and filamentous hemagglutinin at 6, 10, and 24 weeks stratified by maternal Tdap history, and antibody at 32 weeks to HBV, Hib, polio, diphtheria, tetanus, and pneumococcal serotypes. The primary outcome was detectable IgG to both PT and Pertactin at 10 weeks. Results A total of 440 infants (207 girls and 233 boys; median gestation, 39.2 weeks) were randomized to receive the aP vaccine plus HBV (n = 221) or HBV only (control group; n = 219). At 10 weeks, 192 of 206 infants who received the aP vaccine (93.2%) had detectable antibodies to both PT and Pertactin vs 98 of 193 infants in the control group (50.8%) (P Conclusions and Relevance The monovalent aP vaccine is immunogenic and safe in neonates and, if licensed and available, would be valuable for newborns whose mothers did not receive the Tdap vaccine during pregnancy. Trial Registration http://anzctr.org.auIdentifier:ACTRN12609000905268
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Pertactin negative bordetella pertussis demonstrates higher fitness under vaccine selection pressure in a mixed infection model
Vaccine, 2015Co-Authors: Azadeh Safarchi, Helen Marshall, Peter Mcintyre, Sophie Octavia, Laurence Don Wai Luu, Chin Yen Tay, Vitali Sintchenko, Nicholas Wood, Ruiting LanAbstract:Whooping cough or pertussis is a highly infectious respiratory disease in humans caused by Bordetella pertussis. The use of acellular vaccines (ACV) has been associated with the recent resurgence of pertussis in developed countries including Australia despite high vaccination coverage where B. pertussis strains that do not express Pertactin (Prn), a key antigenic component of the ACV, have emerged and become prevalent. In this study, we used an in vivo competition assay in mice immunised with ACV and in naive (control) mice to compare the proportion of colonisation with recent clinical Prn positive and Prn negative B. pertussis strains from Australia. The Prn negative strain colonised the respiratory tract more effectively than the Prn positive strain in immunised mice, out-competing the Prn positive strain by day 3 of infection. However, in control mice, the Prn positive strain out-competed the Prn negative strain. Our findings of greater ability of Prn negative strains to colonise ACV-immunised mice are consistent with reports of selective advantage for these strains in ACV-immunised humans.
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rapid increase in Pertactin deficient bordetella pertussis isolates australia
Emerging Infectious Diseases, 2014Co-Authors: Connie Lam, Helen Marshall, Peter Mcintyre, Nicole Guiso, Sophie Octavia, Vitali Sintchenko, Lawrence Ricafort, Gwendolyn L Gilbert, Nicholas Wood, Anthony D. KeilAbstract:Acellular vaccines against Bordetella pertussis were introduced in Australia in 1997. By 2000, these vaccines had replaced whole-cell vaccines. During 2008–2012, a large outbreak of pertussis occurred. During this period, 30% (96/320) of B. pertussis isolates did not express the vaccine antigen Pertactin (Prn). Multiple mechanisms of Prn inactivation were documented, including IS481 and IS1002 disruptions, a variation within a homopolymeric tract, and deletion of the prn gene. The mechanism of lack of expression of Prn in 16 (17%) isolates could not be determined at the sequence level. These findings suggest that B. pertussis not expressing Prn arose independently multiple times since 2008, rather than by expansion of a single Prnnegative clone. All but 1 isolate had ptxA1, prn2, and ptxP3, the alleles representative of currently circulating strains in Australia. This pattern is consistent with continuing evolution of B. pertussis in response to vaccine selection pressure.