Immunogenicity and safety of a tetravalent E. coli O-antigen bioconjugate vaccine in animal models

BackgroundExtra-intestinal pathogenic Escherichia coli (ExPEC) are major human pathogens; however, no protective vaccine is currently available. We assessed in animal models the immunogenicity and safety of a 4-valent E. coli conjugate vaccine (ExPEC-4V, serotypes O1, O2, O6 and O25 conjugated to Exotoxin A from Pseudomonas aeruginosa (EPA)) produced using a novel in vivo bioconjugation method.MethodsThree doses of ExPEC-4V (with or without aluminum hydroxide) were administered to rabbits (2 μg or 20 μg per O-antigen, subcutaneously), mice (0.2 μg or 2 μg per O-antigen, subcutaneously) and rats (0.4 μg or 4 μg per O-antigen, intramuscularly). Antibody persistence and boostability were evaluated in rats using O6-EPA monovalent conjugate (0.4 μg O-antigen/dose, intramuscularly). Toxicity was assessed in rats (16 μg total polysaccharide, intramuscularly). Serum IgG and IgM antibodies were measured by ELISA.ResultsRobust antigen-specific IgG responses were observed in all animal models, with increased responses in rabbits when administered with adjuvant. O antigen-specific antibody responses persisted up to 168 days post-priming. Booster immunization induced a rapid recall response. Toxicity of ExPEC-4V when administered to rats was considered to be at the no observed adverse effect level.ConclusionsExPEC-4V conjugate vaccine showed good immunogenicity and tolerability in animal models supporting progression to clinical evaluation.     

Immunogenicity,safety and reactogenicity of the pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) in 2–17-year-old children with asplenia or splenic dysfunction: A phase 3 study

BackgroundImmunization with pneumococcal vaccines is an important prophylactic strategy for children with asplenia or splenic dysfunction, who are at high risk of bacterial infections (including S. pneumoniae). This study aimed to assess immunogenicity and safety of pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV, GSK) in this at-risk population.MethodsThis phase III, multi-centre, open-label, controlled study, in which at-risk children with asplenia or splenic dysfunction were enrolled (age strata: 2–4, 5–10 and 11–17 years), was conducted in Poland and the Russian Federation. For the 2–4 years at-risk group, healthy age-matched children were enrolled as control. Unprimed children (not previously vaccinated with any pneumococcal vaccine) received 2 PHiD-CV doses (≥2 months apart) and pneumococcal vaccine-primed children received 1 dose. Immune responses were assessed pre-vaccination and one month post-each dose. Solicited and unsolicited adverse events (AEs) were recorded for 4 and 31 days post-vaccination, respectively, and serious AEs (SAEs) throughout the study.ResultsOf 52 vaccinated children (18 at-risk primed, 28 at-risk unprimed and 6 control unprimed), 45 (18, 23 and 4, respectively) were included in the according-to-protocol cohort for immunogenicity. Post-vaccination (post-dose 1 in primed and post-dose 2 in unprimed children), for each vaccine pneumococcal serotype and vaccine-related serotype 6A all at-risk children had antibody concentrations ≥0.2 µg/mL, and for vaccine-related serotype 19A at least 94.4%. Increases in antibody geometric mean concentrations were observed. For most serotypes, all at-risk children had post-vaccination opsonophagocytic activity (OPA) titers ≥8 and increases in OPA geometric mean titers were observed. No safety concerns were raised. One non-fatal SAE (respiratory tract infection, considered not vaccine-related) was reported by one at-risk unprimed child.ConclusionPHiD-CV was immunogenic and well tolerated in 2–17-year-old children with asplenia or splenic dysfunction.Clinical Trial Registry: www.clinicaltrials.gov, NCT01746108.     

Immunogenicity and persistence of immunity of a quadrivalent Human Papillomavirus (HPV) vaccine in immunocompromised children

AimThe aim of this study was to determine the immunogenicity and reactogenicity of HPV vaccine in immunocompromised children.MethodsA multi-centre clinical trial was conducted in three paediatric hospitals in Australia. Unvaccinated children 5–18 years of age attending one of three paediatric hospitals with a range of specified conditions associated with immunosuppression were included. Quadrivalent HPV vaccine (Gardasil) was given to the participants and serum anti-HPV antibody levels were measured at baseline (before first dose), 7 and 24 months after the first dose of vaccine.ResultsFifty-nine participants were enrolled across the three paediatric hospitals and among those one was seropositive to types 6, 11 and 16 at baseline. Seven months after the first dose, seroconversion rates were 93.3%, 100%, 100% and 88.9% for type 6, 11, 16 and 18 respectively. The corresponding rates at 24 month follow up were 82.2%, 91.1%, 91.1% and 68.9%. The greatest increase in geometric mean titre (GMT) was for type 16, followed by type 11. GMTs declined over the following months, but remained more than fourfold higher for all serotypes compared to baseline titres at 24 months post vaccination. Injection site erythema, pain and swelling were commonly reported local adverse events and were less common after each dose. Few participants reported systemic adverse events, and minor disease flare occurred in two participants. One child developed a squamous cell oral carcinoma during follow up, but tissue was unable to be tested for HPV.ConclusionImmunosuppressed children had an adequate immunogenic response to Quadrivalent HPV vaccine regardless of age and the cause of immunosuppression. HPV related cancers occur at higher frequency and earlier in immunosuppressed patients, so early vaccination and optimal scheduling should be further studied in such children.Clinical trial registration: NCT02263703 (ClinicalTrials.gov)     

Adolescent confidence in immunisation: Assessing and comparing attitudes of adolescents and adults

IntroductionThere is limited knowledge of adolescent views and attitudes towards immunisation. Our study investigated adolescent attitudes to immunisation and compared differences in vaccination attitudes between adolescents and adults.MethodsThis study was a cross-sectional, national online survey. Recruitment was stratified by state and gender to ensure findings were nationally representative. Regression analyses were performed to assess and compare adolescent and adult views on vaccine benefits, community protection, risks, side effects, sources of information, and decision-making preference.ResultsIn 2013, 502 adolescents and 2003 adults completed the online survey. Lower levels of vaccine confidence were observed in adolescents with adolescents less likely to believe vaccines are beneficial and/or safe compared to adults (p = 0.043). Compared to females, males were less confident of vaccine benefits (p < 0.05) but less concern about vaccine side effects (p < 0.05). Adolescents were more concerned about vaccine side effects than adults for pain (p < 0.001), redness or swelling (p < 0.001), and fever (p = 0.006). Adolescents were less likely than adults to consider health professionals (p < 0.001) and the media (e.g. internet) (p = 0.010) as important sources of information, and were more likely to seek information from social networks (p < 0.001) including families and schools. Although 62.0% of adolescents agreed that parents should make the decision about vaccination for them, adolescents were more likely to prefer a joint decision with parents (p < 0.001) or by themselves (p = 0.007) compared with adults.ConclusionAdolescents have a lesser understanding of vaccine safety and benefits than adults and have higher concerns about potential vaccine reactions. Improving adolescent awareness and knowledge of the benefits and risks of vaccination through school-based educational programs may improve confidence in and uptake of vaccines for adolescents and increase vaccine confidence in the next generation of parents.     

Pneumococcal carriage among children after four years of routine 10-valent pneumococcal conjugate vaccine use in Brazil: The emergence of multidrug resistant serotype 6C

BackgroundIn 2010, the 10-valent pneumococcal conjugate vaccine (PCV10) was introduced free of charge in Brazil as part of the public immunization program. Here we investigated the carriage prevalence, colonization risk factors, capsular types, and antimicrobial resistance among pneumococcal isolates obtained from children in Brazil four years after routine PCV10 use.MethodsBetween September and December 2014, we conducted a cross-sectional study among children < 6 years old who attended one public and two private clinics in Niterói, RJ, Brazil to evaluate pneumococcal nasopharyngeal carriage. Antimicrobial susceptibility and capsular types were determined for all isolates.ResultsOf 522 children, 118 (22.6%) were pneumococcal carriers. Being ≥ 2 years old, attending childcare center, presenting with any symptoms, having acute or chronic respiratory disease, and residing in a slum were associated with pneumococcal carriage. The most prevalent capsular types were 6C (14.5%), 15B/C (11.5%), 11A/D (9.2%), and 6A (7.6%). PCV10 serotypes represented 2.5%. All isolates were susceptible to levofloxacin, rifampicin, and vancomycin. Penicillin non-susceptible pneumococci (PNSP) comprised 39%, with penicillin and ceftriaxone MICs ranging from 0.12–8.0 μg/ml and 0.012–1.0 μg/ml, respectively. The 33 (28%) erythromycin-resistant isolates (MICs of 1.5 to >256 μg/ml) displayed the cMLS_B (72.7%) or M (27.3%) phenotypes, harboring the erm(B) and/or mef(A/E) genes. High non-susceptibility rates (>20%) to clindamycin, erythromycin, penicillin, and tetracycline were largely explained by the prevalence of multidrug resistant (MDR) serotype 6C isolates.ConclusionsEffects of universal childhood PCV10 use on carriage were evident, with the near elimination of PCV10 serotypes. The emergence of MDR serotype 6C isolates, however, is a concern. Ongoing surveillance to monitor serotype 6C increase in invasive diseases is warranted.     

Impact of PCV7/PCV13 introduction on invasive pneumococcal disease (IPD) in young children: Comparison between meningitis and non-meningitis IPD

BackgroundThe worldwide introduction of pneumococcal conjugate vaccines (PCV) into National Immunization Programs resulted in rapid and substantial reduction of invasive pneumococcal disease (IPD) rates in children. However, the reduction of meningitis vs. non-meningitis IPD (nm-IPD) was not yet fully elucidated. We compared 7-valent and 13-valent PCV (PCV7 and PCV13) impact on pneumococcal-meningitis vs. nm-IPD in Israeli children <5 years.MethodsWe conducted an ongoing nationwide, prospective, population-based, active surveillance. PCV7 and PCV13 were implemented in Israel in July 2009 and November 2010, respectively. All pneumococcal isolates (blood and/or CSF) from IPD episodes in children <5 years from July 2000 through June 2015 were included. Extrapolation for missing serotypes (34.7% of all isolates) was conducted.Results4163 IPD cases were identified; 3739 nm-IPD (89.8%) and 424 meningitis (10.2%). During the pre-PCV period (2000–2008), children <12 months constituted 52.1% and 33.7% of meningitis and nm-IPD, respectively (p < 0.001). The respective proportions of non-PCV13 serotypes (non-VT) were 18.2% vs. 10.1%, (p < 0.001).Comparing the last study year (2014–2015) to the mean of pre-PCV period, meningitis incidence in children <5 years decreased non-significantly by 27%, while nm-IPD decreased significantly by 69%. Dynamic rates of meningitis and nm-IPD caused by PCV13 serotypes were similar, with 93% and 95% overall reductions, respectively. However, non-VT increased in meningitis relatively to nm-IPD, mainly in children <24 months. Serotype 12F rose sharply and significantly since 2009–2010 through 2014–2015 (28.6% of all non-VT meningitis in children <24 m).ConclusionsThe overall impact of PCV7/PCV13 in children <5 years in Israel was less prominent in meningitis than in nm-IPD. This could be attributed to the younger age of children with meningitis and differences in causative serotypes between the two groups, as the decline of the incidence of meningitis and nm-IPD caused by vaccine-serotypes is similar. Continuous monitoring of meningitis and nm-IPD is warranted.     

Optimizing seroprotection against pneumococcus in children with nephrotic syndrome using the 13-valent pneumococcal conjugate vaccine

BackgroundInfections are among the main life-threatening complications in patients with nephrotic syndrome (NS), in particular with Streptococcus pneumoniae, the first cause of bacterial peritonitis and sepsis in these patients. This study aims to evaluate the baseline seroprotection of NS patients against S. pneumoniae, and immunize them with the 13-valent pneumococcal conjugate vaccine (PCV13) regardless of disease activity and previous immunization history, in order to evaluate the immunogenicity, safety profile, and effect of NS treatment on vaccine responses.MethodsThis multicentre prospective interventional study enrolled 42 children with NS at disease onset or during a regular follow-up appointment. PCV13 was administered at inclusion. Serotype-specific S. pneumoniae IgG titer were assessed at baseline, after immunization, and at 1 year follow-up. Vaccine safety was evaluated clinically and by urinary tests.ResultsPCV13 induced high serotype-specific IgG titers that were maintained at high levels one year after vaccination, even in children previously immunized. No serious adverse event occurred and relapse frequency was unchanged.ConclusionGiven that high IgG titers were achieved and maintained after PCV13 vaccination, and considering the high morbidity related to S. pneumoniae, we propose PCV13 (re-)vaccination for all NS patients, irrespective of their previous immunization history, treatment and disease activity.     

Modeling the long-term antibody response of a hepatitis E vaccine

BackgroundThe first commercialized hepatitis E vaccine, HEV 239, has been shown to be safe and highly immunogenic, the protection as well as the vaccine-induced anti-HEV maintained for at least 4.5 years. However, the longer term persistence of the vaccine-induced anti-HEV responses is unknown.MethodsTwo statistical models, the power-law model and the modified power-law model, were applied to predict the long-term antibody response of the HEV 239 vaccine. The models were fit using the anti-HEV IgG data from a modeling subpopulation of 1278 baseline seronegative vaccinees who seroconverted within one month after finishing the whole vaccination course in the phase 3 trial of HEV 239. In addition, antibody data from a validation subpopulation were used to validate the robustness of the derived models.ResultsIn the vaccinees without pre-vaccination immunity, the power-law model and the modified power-law model estimated that the median duration of the detectable antibody (≥0.077 WU/ml) was 8 years and 13 years, respectively. The power-law model and the modified power-law model estimated that 50% of these vaccinees will maintain detectable levels of anti-HEV IgG for 8 years and >30 years, respectively.ConclusionsThe recombinant hepatitis E vaccine HEV 239 is predicted to provide from 8 years to nearly life-long persistence of anti-HEV IgG above detectable levels. Model predictions are based on conservative mathematical assumptions.(NCT01014845).     

Specific and cross-reactive immune response to oral Salmonella Typhi Ty21a and parenteral Vi capsular polysaccharide typhoid vaccines administered concomitantly

BackgroundSince protective efficacy of the current typhoid vaccines—oral whole-cell Salmonella Typhi Ty21a and parenteral Vi-capsular polysaccharide preparation—is not optimal, and no vaccines are available against paratyphoid or non-typhoidal Salmonella (NTS) serotypes, new approaches deserve to be explored. The immunological mechanisms elicited by the two typhoid vaccines are mainly targeted against different structures. We studied whether these vaccines would enhance S. Typhi-specific immune response and cross-reactivity against other Salmonellae, if administered concomitantly.Materials and methodsVolunteers were immunized simultaneously with Ty21a and Vi vaccines (Ty21a + Vi group) or with either of the two singly (Ty21a and Vi groups). All volunteers were investigated for circulating specific and cross-reactive plasmablasts, identified by ELISPOT as IgA, IgG or IgM antibody-secreting cells (ASC) reactive with S. Typhi, S. Paratyphi A/B/C, or selected NTS serotypes (S. Enteritidis, S. Typhimurium).ResultsIn the Ty21a + Vi group, no specific or cross-reactive plasmablasts were detected before vaccination. After vaccination, the number of S. Typhi-specific plasmablasts (878 ASC/10⁶ PBMC, 95%CI 554–1201) proved higher than in the Ty21a (339 ASC/10⁶ PBMC; p < 0.001) and Vi (149 ASC/10⁶ PBMC; p < 0.001) groups. Likewise, cross-reactive responses in the Ty21a + Vi group were higher than in the Ty21a and Vi groups (Ty21a + Vi vs Ty21a: ASC against S. Paratyphi A/B, S. Enteritidis and S. Typhimurium p < 0.05, against S. Paratyphi C p < 0.01; Ty21a + Vi vs Vi: against S. Paratyphi C not significant, others p < 0.0001). A gut-directed homing profile was seen among O antigen-specific and a systemic one among Vi antigen-specific plasmablasts.ConclusionsConcomitant administration of Ty21a and Vi vaccines is well tolerated and induces an additive immune response to the two vaccines. Thus it enhances the magnitude of both typhoid-specific plasmablast responses and those cross-reacting with paratyphoid and most important NTS serotypes. The data encourage concomitant use of Ty21 and Vi vaccines for those at risk.     

Serotype-specific immune responses to pneumococcal conjugate vaccine among children are significantly correlated by individual: Analysis of randomized controlled trial data

BackgroundThe magnitude of an individual’s serotype-specific immunoglobulin G (IgG) response to a pneumococcal conjugate vaccine (PCV) has been associated with the vaccine’s protective efficacy against carriage of pneumococci of that serotype, though the relationship with other serotypes needs to be understood.MethodsUsing immunogenicity data collected during a trial comparing the 7-valent (PCV7) and 13-valent (PCV13) vaccines, we measured associations between serotype-specific IgG levels, and used multiple regressions to identify demographic predictors of response.ResultsVaccine-induced IgG levels were moderately positively correlated with one another, with pairwise correlation coefficients of 0.40–0.70. Principal component analysis of vaccine-serotype responses yielded one principal component indicating general immune responsiveness, and a second principal component mainly describing responses to serotype 14, which was the least correlated with the other responses. Overall, demographic variables explained only 17.0 and 20.4% of the geometric mean PCV7 and PCV13 responses, respectively. In both groups, older age at the first vaccine dose and shorter time from vaccination to antibody measurement were independently associated with stronger geometric mean responses.DiscussionImproved understanding of the nature and causes of variation in immune response may aid in optimizing vaccination schedules and identifying robust correlates of protection.     

Decennial administration in young adults of a reduced-antigen content diphtheria,tetanus, acellular pertussis vaccine containing two different concentrations of aluminium

BackgroundRegular booster vaccination might be necessary throughout life to protect against pertussis infection. Nevertheless the duration of protection after booster vaccination remains unclear. In this study, antibody persistence up to 10 years after previous vaccination of adolescents (N = 478) with combined reduced-antigen-content diphtheria-tetanus-acellular pertussis vaccine (dTpa, Boostrix™, GlaxoSmithKline Belgium) containing 0.5 mg, 0.3 mg or 0.133 mg of aluminium was assessed. The immunogenicity, reactogenicity and safety of a decennial booster dTpa dose were also investigated.MethodsYoung adults vaccinated as adolescents in the initial booster study were invited to participate in an assessment of antibody persistence at years 8.5 and 10, and to receive a dTpa booster dose at year 10 with immunogenicity assessment one month later. Those who originally received the 0.5 mg or 0.3 mg formulations received the same vaccine at year 10. Those in the 0.133 mg group received the 0.5 mg formulation. Reactogenicity and safety endpoints were captured until 30 days after booster vaccination.ResultsPrior to the decennial booster at year 8.5 and year 10, all participants had seroprotective antibodies for diphtheria (ELISA or neutralisation assay) and tetanus. At least 77.8% were seropositive for anti-pertussis toxin (PT) antibodies at year 8.5 and 82.8% at year 10. All participants were seropositive for antibodies for filamentous haemagglutinin and pertactin at both time points. The decennial booster dose induced robust increases in antibody GMCs to all antigens. The post-booster anti-PT geometric mean concentration was 82.5 EL.U/ml (95%CI 67.0–101.6) and 124.0 (103.5–148.5) in the 0.3 mg and 0.5 mg groups, respectively. The reactogenicity and safety profile of the decennial booster dose was consistent with the known safety profile of dTpa. No serious adverse events were reported.ConclusionsDecennial booster vaccination with either of the two licensed formulations of dTpa was highly immunogenic and well tolerated in young adults. Either formulation could be confidently used as a decennial booster.This study is registered at www.clinicaltrials.gov NCT01147900     

Clinician knowledge,clinician barriers,and perceived parental barriers regarding human papillomavirus vaccination: Association with initiation and completion rates

PurposeWe tested the hypothesis that clinician knowledge, clinician barriers, and perceived parental barriers relevant to the human papillomavirus (HPV) vaccination account for the variation in vaccine delivery at the practice-site level.MethodsWe conducted a survey from October 2015 through January 2016 among primary care clinicians (n = 280) in a 27-county geographic region to assess clinician knowledge, clinician barriers, and perceived parental barriers regarding HPV vaccination. Primary care clinicians included family medicine physicians, general pediatricians, and family and pediatric nurse-practitioners. We also used the Rochester Epidemiology Project to measure HPV vaccination delivery. Specifically we used administrative data to measure receipt of at least one valid HPV vaccine dose (initiation) and receipt of three valid HPV vaccine doses (completion) among 9–18 year old patients residing in the same 27-county geographic region. We assessed associations of clinician survey data with variation in vaccine delivery at the clinical site using administrative data on patients aged 9–18 years (n = 68,272).ResultsConsistent with our hypothesis, we found that greater knowledge of HPV and the HPV vaccination was associated with higher rates of HPV vaccination initiation (Incidence rate ratio [IRR] = 1.05) and completion of three doses (IRR = 1.28). We also found support for the hypothesis that greater perceived parental barriers to the HPV vaccination were associated with lower rates of initiation (IRR = 0.94) and completion (IRR = 0.90). These IRRs were statistically significant even after adjustment for site-level characteristics including percent white, percent female, percent ages 9–13, and percent with government insurance or self-pay at each site.ConclusionsClinician knowledge and their report of the frequency of experiencing parental barriers are associated with HPV vaccine delivery rates—initiation and completion. Higher measures of knowledge correlated with higher rates. Fewer perceived occurrences of parental barriers correlated with lower rates. These data can guide efforts to improve HPV vaccine delivery in clinical settings.     

Comparative incidence dynamics and serotypes of meningitis,bacteremic pneumonia and other-IPD in young children in the PCV era: Insights from Israeli surveillance studies

IntroductionWidespread introduction of pneumococcal conjugated vaccines (PCVs) impacted on invasive pneumococcal disease (IPD). However, IPD reduction may not be similar in all outcomes within IPD.We assessed PCV7/PCV13 impact on pneumococcal meningitis, bacteremic pneumonia (BP) and other (non-meningitis, non-pneumonia) IPD episodes in children <5 years in Israel.MethodsA prospective, population-based, active nationwide surveillance.All pneumococcal invasive episodes with positive blood/CSF cultures, July 2000 through June 2016, were included. Three sub-periods were defined: pre-PCV (2000–2008), PCV7 (2009–2011) and PCV13 (2014–2016). Incidence rate ratios (IRRs) were calculated.ResultsOverall, 4321 episodes were recorded; 456 (10.6%) meningitis, 1478 (34.2%) pneumonia and 2387 (55.2%) other-IPD.In the pre-PCV period, proportion of serotypes in PCV13, but not in PCV7 (mainly serotypes 1, 5 and 19A) was higher in BP (43.3%) compared with other-IPD episodes (32.8%, p < 0.001) and similar to that of meningitis (37.6%, p = 0.1). The proportion of episodes in children <12 months was higher in meningitis (52.1%) compared with pneumonia (23.2%) and other-IPD episodes (39.5%; p < 0.001 for both).The declines of the 3 entities were not similar; Meningitis rate non-significantly declined by 24% (IRR = 0.76; 95% CI 0.57–1.01), while BP and other-IPD rates significantly declined by 57% and 70%, respectively. In contrast to other entities, BP did not decline significantly after PCV7 introduction but started to decline only after PCV13 introduction.Rates of meningitis, pneumonia and other-IPD caused by PCV13-serotypes (VT13) substantially declined by 88%, 95% and 97%, respectively, comparing PCV13 and the pre-PCV periods. However, diseases caused by non-VT13 increased by 256%, 302% in meningitis and pneumonia, respectively, but only 116% in other-IPD.ConclusionsFollowing PCV7/PCV13 introduction, rates of episodes caused by VT13 were substantially reduced in all 3 groups. However, differences in age distribution, serotype replacement and specific serotype decrease suggest different pathogenesis and host susceptibility between the 3 entities.     

Reduced schedules of 4CMenB vaccine in infants and catch-up series in children: Immunogenicity and safety results from a randomised open-label phase 3b trial

BackgroundThis study evaluated the immunogenicity and safety of a licensed meningococcal serogroup B vaccine (4CMenB) administered alone according to reduced schedules in infants or catch-up series in children.MethodsIn this open-label, multicentre, phase 3b study (NCT01339923), infants randomised 1:1:1 received 4CMenB: 2 + 1 doses at 3½–5–11 months or 6–8–11 months of age, 3 + 1 doses at ages 2½–3½–5–11 months. Children aged 2–10 years received 2 catch-up doses administered 2 months apart. Immune responses were measured by hSBA assays against 4 strains specific for vaccine components fHbp, NadA, PorA and NHBA. Sufficiency of immune responses was defined in groups with 2 + 1 doses schedules as a lower limit ≥70% for the 97.5% confidence interval of the percentage of infants with hSBA titres ≥4, 1 month post-dose 2 for fHbp, NadA, PorA. Adverse events were collected for 7 days post-vaccination; serious adverse events (SAEs) throughout the study.Results754 infants and 404 children were enrolled. Post-primary vaccination, 98–100% of infants across all groups developed hSBA titres ≥4 for fHbp, NadA, PorA, and 48–77% for NHBA. Sufficiency of immune responses in infants receiving 2 + 1 schedules was demonstrated for fHbp, NadA, PorA after 2 doses of 4CMenB, as pre-specified criteria were met. Following receipt of 2 catch-up doses, 95–99% of children developed hSBA titres ≥4 for 4CMenB components. Similar safety profiles were observed across groups. A total of 45 SAEs were reported, 3 of which were related to vaccination.ConclusionReduced infant schedules and catch-up series in children were immunogenic and safe, having the potential to widen 4CMenB vaccine coverage.FundingGlaxoSmithKline Biologicals SA.     

Safety,tolerability, and immunogenicity of a 4-antigen Staphylococcus aureus vaccine (SA4Ag): Results from a first-in-human randomised,placebo-controlled phase 1/2 study

BackgroundA prophylactic Staphylococcus aureus four-antigen vaccine (SA4Ag) is under development for prevention of invasive S. aureus disease. A preliminary S. aureus three-antigen vaccine (SA3Ag) was reformulated to include a novel manganese transporter protein (MntC or rP305A). This study describes the first-in-human dose-finding, safety, and immunogenicity results for SA4Ag.MethodsIn this double-blind, sponsor-unblind, placebo-controlled, phase 1/2 study, 454 healthy adults aged 18–64 years were randomised to receive a single dose of one of three formulations of SA4Ag with escalating dose levels of rP305A or placebo. Functional immune responses were measured using opsonophagocytic activity (OPA) killing and fibrinogen-binding inhibition (FBI) assays; antigen-specific immunogenicity was assessed using a four-plex competitive Luminex® immunoassay (cLIA).ResultsA high proportion of SA4Ag recipients met the pre-defined antibody thresholds for each antigen at Day 29. A substantial and dose-level dependent immune response was observed for rP305A, with up to 18-fold rises in cLIA titres at Day 29. Robust functional responses were demonstrated, with >80-fold and >20-fold rises in OPA assay titres at Day 29 using S. aureus strains expressing capsular polysaccharide serotypes 5 and 8, respectively. Durable antibody responses were observed through month 12, gradually waning from peak levels achieved by days 11–15. SA4Ag was well tolerated, and no vaccine-related serious adverse events were reported.ConclusionsSingle-dose vaccination of SA4Ag in healthy adults aged 18–64 years safely induced rapid and robust functional immune responses that were durable through month 12, supporting further development of this vaccine. Trial registration number: NCT01364571     

Using the 4 Pillars™ Practice Transformation Program to increase adolescent human papillomavirus,meningococcal, tetanus-diphtheria-pertussis and influenza vaccination

ObjectivesTo report the results of an intervention using the 4 Pillars™ Practice Transformation Program (4 Pillars™ Program) to increase adolescent vaccinations including human papillomavirus vaccine (HPV) and influenza vaccines, which remain underutilized in this population.Study designEleven pediatric and family medicine practices, previously control sites from a randomized controlled cluster trial, with ≥50 adolescent patients participated. The 4 Pillars™ Program was the foundation of the intervention. De-identified demographic, office visit and vaccination data were derived from electronic medical record extractions for patients whose date of birth was 4/1/1997 to 4/1/2004 (ages 11–17 years at baseline). Vaccination rates for HPV, influenza, tetanus-pertussis-diphtheria (Tdap) and meningococcal (MenACWY) vaccines were determined for all eligible patients pre- and post intervention (i.e., vaccination rates on 4/1/2015 and 4/30/2016).ResultsAmong 9473 patients ages 11–17 years at baseline (4/1/2015), mean pre-intervention vaccination rates for HPV initiation and completion, meningococcal, Tdap and influenza vaccines were below national levels. Rates increased significantly post intervention (P < 0.001) for HPV initiation which increased 17.1 percentage points (PP) from 51.4%; HPV completion increased 14.8 PP from 30.7%, meningococcal vaccine uptake increased 16.6 PP from 79.1%, Tdap vaccine uptake increased 14.6 PP from 76.9%. Influenza vaccine uptake did not increase significantly (2.3 PP from 40.1%). In the regression using generalized estimating equations, odds of vaccination were higher for younger, non-white adolescents for all vaccines; being in a smaller practice decreased the odds of Tdap vaccination but increased the odds of influenza vaccination.ConclusionClinically and statistically significant improvements in HPV series initiation and completion, and meningococcal and Tdap vaccinations were observed in primary care practices implementing the 4 Pillars™ Practice Transformation Program.Clinical Trial Registry Number: NCT02165722.     

Cost-effectiveness analysis of catch-up hepatitis A vaccination among unvaccinated/partially-vaccinated children

BackgroundSince 2006, the US Centers for Disease Control and Prevention has recommended hepatitis A (HepA) vaccination routinely for children aged 12–23 months to prevent hepatitis A virus (HAV) infection. However, a substantial proportion of US children are unvaccinated and susceptible to infection. We present results of economic modeling to assess whether a one-time catch-up HepA vaccination recommendation would be cost-effective.MethodsWe developed a Markov model of HAV infection that followed a single cohort from birth through death (birth to age 95 years). The model compared the health and economic outcomes from catch-up vaccination interventions for children at target ages from two through 17 years vs. outcomes resulting from maintaining the current recommendation of routine vaccination at age one year with no catch-up intervention.ResultsOver the lifetime of the cohort, catch-up vaccination would reduce the total number of infections relative to the baseline by 741 while increasing doses of vaccine by 556,989. Catch-up vaccination would increase net costs by $10.2 million, or $2.38 per person. The incremental cost of HepA vaccine catch-up intervention at age 10 years, the midpoint of the ages modeled, was $452,239 per QALY gained. Across age-cohorts, the cost-effectiveness of catch-up vaccination is most favorable at age 12 years, resulting in an Incremental Cost-Effectiveness Ratio of $189,000 per QALY gained.ConclusionsGiven the low baseline of HAV disease incidence achieved by current vaccination recommendations, our economic model suggests that a catch-up vaccination recommendation would be less cost-effective than many other vaccine interventions, and that HepA catch-up vaccination would become cost effective at a threshold of $50,000 per QALY only when incidence of HAV rises about 5.0 cases per 100,000 population.     

Tetanus,diphtheria, and acellular pertussis vaccination during pregnancy and reduced risk of infant acute respiratory infections

BackgroundTo protect infants from pertussis infection, the Advisory Committee on Immunization Practices (ACIP) recommends women receive the tetanus toxoid, reduced diphtheria toxoid, acellular pertussis (Tdap) vaccine between 27 and 36 weeks of pregnancy. Here, we assessed the association between timing of maternal Tdap vaccination during pregnancy and acute respiratory infection (ARI) in infants <2 months of age.MethodsThis retrospective cohort study included 99,434 infants born to active duty military women in the Department of Defense Birth and Infant Health Registry from 2006 through 2013. Multivariable log-binomial regression was used to calculate relative risks (RRs) and 95% confidence intervals (CIs) for the association between maternal Tdap vaccination during pregnancy and infant ARI at <2 months of age.ResultsInfants of mothers who received Tdap vaccination during pregnancy vs those who did not were 9% less likely to be diagnosed with an ARI at <2 months of age (RR, 0.91; 95% CI, 0.84–0.99), and the risk was 17% lower if vaccination was received between 27 and 36 weeks of pregnancy (RR, 0.83; 95% CI, 0.74–0.93). Similar results were observed when comparing mothers who received Tdap vaccination prior to pregnancy in addition to Tdap vaccination between 27 and 36 weeks of pregnancy versus mothers who only received vaccination prior to pregnancy (RR, 0.85; 95% CI, 0.74–0.98).ConclusionsMaternal Tdap vaccination between 27 and 36 weeks of pregnancy was consistently protective against infant ARI in the first 2 months of life vs no vaccination during pregnancy, regardless of Tdap vaccination prior to pregnancy. Our findings strongly support current ACIP guidelines recommending Tdap vaccination in late pregnancy for every pregnancy.