Maternal immunization with pneumococcal 9-valent conjugate vaccine and early infant otitis media

A randomized trial of an investigational 9-valent pneumococcal conjugate vaccine (PCV-9) or placebo given to pregnant women during the last trimester to prevent early infant otitis media (OM) was conducted. All infants received Prevnar^® at 2, 4, 6, and 12 months. Clinic and adverse event records were reviewed to identify OM. Variables significantly related to acute OM by age 6 months (p < 0.05) were: vaccine group (9 valent or placebo), sibling history of tympanostomy tubes, upper respiratory infection, and number of clinic visits by 6 months. Infant OM rates were similar between 6 and 12 months (58% and 56%). Results suggested that immunizing pregnant women with PCV-9 increased infants’ risk of acute OM in the first 6 months of life, and this correlated with decreased infant antibody responses to their infant Streptococcus pneumoniae vaccine serotypes, but did not influence antibody responses to 3 other serotypes two of which were in maternal vaccine (types 1 and 5) and one was a control (type 7F). Explanations for these results include dampening of infant antibody production by high levels of passively acquired maternal pneumococcal antibodies and/or altered B lymphocyte immune responses in infants exposed to these specific polysaccharide antigens in utero.     

Role of antibodies and IL17-mediated immunity in protection against pneumococcal otitis media

Widespread vaccination against Streptococcus pneumoniae (the pneumococcus) has significantly reduced pneumococcal disease caused by vaccine serotypes. Despite vaccination, overall pneumococcal colonization rates in children have not reduced and otitis media (OM) by non-vaccine serotypes remains one of the most common childhood infections. Pneumococcal surface protein A (PspA) has been shown to be a promising protein antigen to induce broad protection against pneumococcal colonization. However, its ability to protect against OM remains unclear. Using our previously established mouse model of influenza-virus induced pneumococcal OM, we here show that intranasal vaccination of mice with PspA together with the mucosal adjuvant CTB results in a decrease in pneumococcal load in the middle ears. This decrease correlated with the induction of PspA-specific IgA, a balanced IgG1:IgG2a antibody response and the induction of a mucosal Th17 response. Our data suggests that the IL-17 response to PspA is more important for protection against OM, whilst the presence of antibodies may be less important, as determined in mice deficient in IL-17 signaling or antibody production. Together, these results suggest that mucosal vaccination with PspA may not only protect against colonization, but also against the development of virus-induced pneumococcal OM.     

7-Valent pneumococcal conjugate vaccine and otitis media: Effectiveness of a 2-dose versus 3-dose primary series

Background

Seven-valent pneumococcal conjugate vaccination (PCV7) has been shown to reduce rates of otitis media (OM) when given as a 2- or 3-dose primary series followed by a booster dose. However, data on the 2- or 3-dose primary series’ relative effectiveness against OM is very limited. Using data from the United States after the 2000 introduction of PCV7, we compared the effectiveness of a 2- versus a 3-dose primary series against acute otitis media (AOM).

Methods

We examined the 2002 birth cohort from the Medstat MarketScan insurance claims database and compared the incidence of AOM in children that received two or three doses in the primary PCV7 series using propensity score matching. We assessed AOM rates after completion of the primary series and before the booster dose, and after the booster dose until four years of age.

Results

Among the 2002 birth cohort captured by MarketScan, we identified 38,786 children we could match with immunization data; of these 8515 (22%) received a 2-dose primary series and 10,152 (26%) received a 3-dose primary series. After matching, cumulative AOM incidence between 6 and 12 months among children who did not receive a PCV7 dose between the primary series and the booster dose was 37.6% for the 2-dose series and 35.0% for the 3-dose series. This difference was not statistically significant (p = 0.22). Cumulative AOM incidence between one and four years, i.e., after the booster dose, was 104.4% for the 2-dose primary series and 102.5% for the 3-dose primary series, and the difference between them was also statistically insignificant.

Conclusion

In a population of highly-insured children, a 2-dose primary series of PCV7 appears to provide similar protection against AOM as a 3-dose primary series. These data have important implications for national immunization programs where AOM is an important driver of cost-effectiveness.     

High pneumococcal serotype specific IgG,IgG1 and IgG2 levels in serum and the middle ear of children with recurrent acute otitis media receiving ventilation tubes

Recurrent acute otitis media (AOM), frequently caused by Streptococcus pneumoniae, is a major paediatric health problem. A reduced antibody response against pneumococcal polysaccharides may contribute to an increased susceptibility to AOM. Using a multiplex bead-based assay we measured IgG, IgG1 and IgG2 levels against 11 pneumococcal polysaccharides in serum samples from 166 children below 3 years of age with a history of at least 3 episodes of acute otitis media receiving ventilation tubes, and 61 healthy controls. Pneumococcal serotype specific IgG was also determined in 144 middle ear effusion samples. Pneumococcal serotype specific IgG, IgG1 and IgG2 levels were similar in children with or without AOM, except for IgG and IgG1 levels against serotype 5, which were significantly higher in children with a history of frequent AOM (IgG: 137.5 μg/ml vs. 84.0 μg/ml; p = 0.02; IgG1: 24.5 μg/ml vs. 18.2 μg/ml; p = 0.05). The age-related development of pneumococcal serotype-specific IgG, IgG1 and IgG2 levels was similar in children with or without a history of AOM. Pneumococcal serotype specific IgG was present in middle ear effusion and these levels correlated significantly with serum titres. Children with a history of frequent AOM receiving ventilation tubes do not have a deficient IgG, IgG1 or IgG2 response against pneumococcal polysaccharides, either induced by vaccination or due to natural exposure. The strong correlation between IgG levels in serum and the middle ear suggests parenteral pneumococcal conjugate vaccination induces antibodies in the middle ear which may therefore contribute to reducing the burden of AOM.     

Pneumococcal carriage and acute otitis media induce serum antibodies to pneumococcal surface proteins CbpA and PhtD in children

We assessed the development and role of serum anti-CbpA and -PhtD in early childhood in relation to pneumococcal exposure. Serum IgG concentrations to CbpA and PhtD were measured with enzyme immunoassay in serum samples collected at the ages of 6, 12, 18, and 24 months from 50 healthy children and from 50 adults. Furthermore, antibodies to CbpA, PhtD and the C-terminal fragment of PhtD (PhtD C) were measured in serum samples collected at 12 (N = 286) and 18 months (N = 259) to evaluate the risk of subsequent pneumococcal acute otitis media (AOM) in relation to antibody concentrations. The increase in anti-CbpA and -PhtD concentrations was related to prior pneumococcal exposure. At 12 and 18 months, in the risk model of pneumococcal AOM adjusted for prior pneumococcal AOM, higher concentrations of anti-CbpA, but not anti-PhtD, were associated with a lowered risk of subsequent pneumococcal AOM. In conclusion, pneumococcal exposure induces the development of serum anti-CbpA and -PhtD in early childhood. Anti-CbpA antibodies may play a role in the prevention of subsequent pneumococcal AOM during the second year of life.     

Acute exercise enhancement of pneumococcal vaccination response: A randomised controlled trial of weaker and stronger immune response

Acute exercise at the time of vaccination can enhance subsequent immune responses. However, the potential benefit of this effect will be its efficacy in boosting poor responses, and thus protection in at-risk populations. The current study tested the effect of exercise on the response to either a full- or half-dose Pneumococcal (Pn) vaccination to elicit stronger and weaker responses. Subjects were 133 young healthy adults, randomised to one of four groups: exercise or control task, receiving a full- or half-dose Pn vaccination. Prior to vaccination, exercise groups completed a 15 min arm and shoulder exercise task, control groups rested quietly. Antibody levels to 11 Pn strains were evaluated at baseline and 1-month. Across all participants, exercise groups showed significantly greater increase in antibody levels than control groups. When doses were compared, it emerged that those who exercised had significantly larger responses than those who rested in the half-dose group, but in the full-dose groups responses were similar. This data indicates the effectiveness of exercise as a vaccine adjuvant, particularly in weaker responses. Thus, given the potential public health benefits of no-cost behavioural intervention to enhance response to vaccination, testing in at-risk populations should be pursued.     

Vaccination status and immune response to 13-valent pneumococcal conjugate vaccine in asplenic individuals

Overwhelming post-splenectomy infection (OPSI) is immediately life-threatening and vaccination against encapsulated bacteria, in particular pneumococci, decreases its incidence.First, we investigated the adherence to vaccination guidelines in a retrospective study of the hospital records of splenectomised patients. Second, patients were asked to complete a questionnaire and invited to participate in a study where 12-valent pneumococcal serotype-specific IgG concentrations were determined before and 4 to 6 weeks after vaccination with PCV13.Of 79 individuals who underwent splenectomy between 2000 and 2012: 81.0% received pneumococcal vaccine, 51.9% received vaccine against Haemophilus influenzae type B and 22.8% received meningococcal vaccine. 31 individuals were deceased. 33 individuals completed questionnaires and accepted participation in the second part of the study. The participants consisted of two groups: (1) prior PPV23 (n = 24) and (2) prior PPV23 + PCV13 (n = 9). In group 1, pre-PCV13 GMC's ≥ 0.35 μg/mL were observed for serotypes 1, 4, 6B, 7F, 9V, 14, 18C, 19A, 19F and 23F, and GMC's < 0.35 μg/mL for serotypes 3 and 5, significant increases pre- to post-PCV13 were found for serotypes 1, 3, 4, 5, 7F, 18C, 19A, 23F (p ≤ 0.001) and 19F (p = 0.01) and all 12 serotypes-specific GMC were above 0.35 μg/mL after vaccination. Group 2 did not receive vaccine in this study, but blood tests showed all 12 serotype-specific GMC > 0.35 μg/mL.Adherence to guidelines regarding primary pneumococcal vaccination was adequate but only a minority received the recommended meningococcal vaccination.High levels of pneumococcal serotype-specific antibodies were observed in the previous PPV23 vaccinated group, and more pronounced in the previous PCV13 group, and our data suggests that PCV13 is immunogenic for serotypes 1, 3, 4, 5, 7F, 18C, 19A, 19F and 23F, if used as a booster dose in asplenic patients with previous PPV23 vaccination.     

A randomized,controlled trial comparing the immunogenicity and safety of a 23-valent pneumococcal polysaccharide vaccination to a repeated dose 13-valent pneumococcal conjugate vaccination in adult liver transplant recipients

BackgroundSolid organ transplant (SOT) patients are at significant risk for invasive pneumococcal disease. The optimal pneumococcal vaccination strategy for SOT patients is not known.MethodsThe potential adult liver transplant recipients were randomised into two arms: to receive a 23-valent pneumococcal polysaccharide vaccine (PPV23) before the transplantation or to receive a 13-valent pneumococcal conjugate vaccine (PCV13) before the transplantation and a second dose of PCV13 six months after the transplantation. Serotype-specific antibody concentrations and opsonophagocytic activity (OPA) were measured before and after the first vaccination (visits V1,V2) and six and seven months after the transplantation, e.g. before and after the second PCV13 (visits V3,V4).ResultsOut of 47 patients, 19 (PCV13 arm) and 17 (PPV23 arm) received a liver transplant and all these patients completed the study (36/47, 76,6%). Each vaccine schedule elicited a good immune response. At V2, the geometric mean concentrations (GMĆs) of antibodies for serotypes 6A, 7F and 23F, and the geometric mean titers (GMT́s) of OPA for serotypes 4, 6A, 6B and 23F were significantly higher for PCV13, but the proportions of patients reaching OPA cut-off ≥ 8 or ELISA cut-off ≥ 1.0 µg/ml did not differ between the arms. At V3 the antibody concentrations and the OPA had declined to baseline in both arms. The second PCV13 vaccination elicited an immune response. There was no difference in adverse events. No vaccine-related allograft rejection was detected.ConclusionsThe immunogenicity of PPV23 and PCV13 was comparable in this patient material, but the seroresponses waned after transplantation. The second dose of PCV13 restored the immune responses and was well tolerated.     

Reduction in the incidence of invasive pneumococcal disease after general vaccination with 7-valent pneumococcal conjugate vaccine in Germany

General vaccination with the 7-valent pneumococcal conjugate vaccine was recommended in Germany in July 2006 for all children <2 years. The proportion of reported invasive pneumococcal disease (IPD) caused by vaccine serotypes before vaccine introduction was considerably lower than in the US.     

Immune response to pneumococcal conjugate vaccine in patients with systemic vasculitis receiving standard of care therapy

AimTo study the effect of standard of care therapy on antibody response and functionality following immunization with 13-valent pneumococcal conjugate vaccine (PCV13) in patients with primary systemic vasculitis compared to healthy controls.Methods49 patients with vasculitis and 49 controls received a single dose (0.5 ml) PCV13 intramuscularly. Ongoing treatments: azathioprine (AZA; n = 11), cyclophosphamide (CYC; n = 6), methotrexate (MTX; n = 9), rituximab (n = 3); anti-TNF (n = 2), mycophenolate mofetil (n = 2), prednisolone alone (n = 15) and no active treatment (n = 2). Specific antibody concentrations for serotypes 6B and 23F were determined using ELISA and opsonophagocytic activity (OPA) assay (23F) was performed, on serum samples taken immediately before and 4–6 weeks after vaccination. Proportion of individuals with putative protective antibody concentration (≥1.0 µg/mL) and positive antibody response (≥2-fold increase from prevaccination concentration) for both serotypes were calculated and groups were compared.ResultsAt baseline, 6 patients (12%) and 12 controls (24%) had protective antibody levels for both serotypes. After vaccination, antibodies increased for both serotypes in patients and controls (p < 0.001), 32 patients (65%) and 35 controls (71%) reached protective level for 6B, and 32 patients (65%) and 37 controls (76%) for 23 F. Compared to controls, patients had lower prevaccination geometric mean concentration (23F, p = 0.01) and a numerical trend towards lower prevaccination level (6B) and postvaccination levels (both serotypes). Patients with prednisolone alone had lower prevaccination OPA (p < 0.01) compared to controls. OPA increased after vaccination in both patients and controls (p < 0.001), but improvement was better in controls (p = 0.001). AZA, CYC or MTX, but not prednisolone alone, tended towards a lower proportion of patients reaching protective antibody levels (p = 0.06), compared to controls.ConclusionsPneumococcal conjugate vaccine was safe and immunogenic in patients with established vasculitis. Treatment with DMARDs, mostly AZA, CYC and MTX but not systemic prednisolone may impair antibody response.Trial registration. ClinicalTrials.gov Identifier: NCT02240888. Registered 4 September, 2014     

Global serotype distribution among Streptococcus pneumoniae isolates causing otitis media in children: Potential implications for pneumococcal conjugate vaccines

Acute otitis media (AOM) is the most common infection following pneumococcal colonization of the upper respiratory tract. Streptococcus pneumoniae causes 30–60% of AOM cases worldwide. However, not all pneumococcal serotypes cause disease and an association exists with nasopharyngeal colonization by certain serotypes and their propensity to cause AOM. This review examines the global serotype distribution relationship between pneumococcal serotypes and AOM in children aged <18 years and demonstrates that the most common pneumococcal serotypes causing AOM globally are 3, 6A, 6B, 9V, 14, 19A, 19F, and 23F.     

A retrospective cohort study investigating the comparative effectiveness of pneumococcal vaccines against hospitalisation with otitis media and pneumonia in New Zealand

BackgroundSince 2008 New Zealand has used three different formulations of pneumococcal vaccines on the national infant schedule, PCV7, PCV10 and PCV13, switching between PCV10 and PCV13 twice in 10 years. We have used New Zealand’s linkable, administrative health data to examine the comparative risk of otitis media (OM) and pneumonia hospitalisations among children receiving three different pneumococcal conjugate vaccines (PCV).MethodsThis was a retrospective cohort study using linked administrative data. Outcomes were otitis media, all cause pneumonia and bacterial pneumonia related hospitalisation for children in three cohorts representing periods where PCVs transitioned between PCV7, PCV10, PCV13 and back to PCV10 between 2011 and 2017. Cox’s proportional hazard regression was used to provide hazard ratio estimates to compare outcomes for children vaccinated with different vaccine formulations and to adjust for different sub population characteristics.ResultsEach observation period, where different vaccine formulations coincided, and therefore comparable with respect to age and the environment, included over fifty-thousand infants and children. PCV10 was associated with a reduced risk for OM compared with PCV7 (Adjusted HR 0.89, 95 %CI 0.82–0.97). There were no significant differences between PCV10 and PCV13 in risk of hospitalisation with either otitis media or all-cause pneumonia amongst the transition 2 cohort. In the 18 -month follow-up, after transition 3, PCV13 was associated with a marginally higher risk of all-cause pneumonia and otitis media compared to PCV10.ConclusionThese results should offer reassurance about the equivalence of these pneumococcal vaccines against the broader pneumococcal disease outcomes OM and pneumonia.     

Does pneumococcal conjugate vaccination affect onset and risk of first acute otitis media and recurrences? A primary care-based cohort study

Background

It has been hypothesized that widespread implementation of pneumococcal conjugate vaccination (PCV) in infancy reduces early AOM and thereby prevents further AOM episodes and associated health care resource use.

Predominance of nontypeable Haemophilus influenzae in children with otitis media following introduction of a 3+0 pneumococcal conjugate vaccine schedule

In Australia the 7-valent pneumococcal conjugate vaccine (PCV7) is administered at 2, 4 and 6 months of age, with no booster dose. Information on bacterial carriage and the aetiology of recurrent acute otitis media (rAOM) after introduction of PCV7 using the 3 + 0 schedule is required to evaluate the potential impact of second generation pneumococcal vaccines. We found that 2-4 years after introduction of PCV7 in the National Immunisation Program, nontypeable Haemophilus influenzae (NTHi) was the predominant pathogen isolated from the nasopharynx and middle ear of children with a history of rAOM. Compared with healthy controls (n = 81), NTHi and Streptococcus pneumoniae carriage rates were significantly higher in children with a history of rAOM (n = 186) (19% vs. 56% p < 0.0001 and 26% vs. 41%, p = 0.02, respectively). Carriage of PCV7 pneumococcal serotypes was rare, whereas PCV7-related and non-PCV7 serotypes were isolated of 38% of cases and 24% of controls. Serotype 19A was the most common serotype isolated from the nasopharynx and middle ear and accounted for 36% (14/39) of total pneumococcal isolates with reduced susceptibility to cotrimoxazole. Of the 119 children carrying NTHi, 17% of isolates were β-lactamase positive.The scarcity of PCV7 serotypes in children with and without a history of rAOM indicates that the 3 + 0 PCV7 schedule is preventing carriage and rAOM from PCV7 serotypes. Introduction of new vaccines in Australia with increased pneumococcal serotype and pathogen coverage, including 19A and NTHi, should decrease the circulation of antibiotic-resistant bacteria and reduce the burden of rAOM.     

Four years of universal pneumococcal conjugate infant vaccination in Germany: Impact on incidence of invasive pneumococcal disease and serotype distribution in children

Introduction

Vaccination with pneumococcal conjugate vaccine (PCV) for all children <2 years was recommended in Germany in July 2006. Initially PCV7 was exclusively used; PCV10 became available from April 2009 and PCV7 was replaced by PCV13 in December 2009.

Objective

To compare the incidence and serotype distribution of invasive pneumococcal disease (IPD) for pneumococcal meningitis and non-meningitis IPD in children from 2007 to 2010 with reference to the pre-vaccination period from 1997 to 2001.

Methods

Nationwide surveillance of IPD for children <16 years in Germany was based on two independent reporting sources: active surveillance in paediatric hospitals and passive web-based surveillance through microbiological laboratories. Serotyping was performed using the Neufeld Quellung reaction. Case definition: isolation of Streptococcus pneumoniae from a normally sterile body site. IPD incidence was estimated by capture–recapture analysis. Rate ratios comparing post- to pre-vaccination incidence were calculated as well as PCV7 and non-PCV7 serotype specific incidences.

Results

While PCV7 incidence decreased by 88% (95%CI: 83 to 91) in children <16 years both in pneumococcal meningitis and non-meningitis IPD, an increase in Non-PCV7 serotypes was observed which was more pronounced in non-meningitis cases (168%; 95%CI: 140–257) than in pneumoccocal meningitis (65%; 95%CI: 23–123). The changes in incidence after four years were: <16 years: −35% (95%CI: −49 to −19), <2 years: −46% (95%CI: −61 to −27) for pneumococcal meningitis and + 11% (95%CI: −4 to  + 29) and −26% (95%CI: −41 to −7) for non-meningitis IPD respectively.

Conclusion

Infant PCV7 vaccination in Germany prompted a decrease in the incidence of pneumococcal meningitis similar to that observed in England/Wales. In non-meningitis IPD the decrease was smaller and confined to the age group <2 years with no change or an increase in incidence in other age groups pointing to potential ascertainment bias due to increased blood-culturing.     

Modeling pneumococcal nasopharyngeal acquisition as a function of anticapsular serum antibody concentrations after pneumococcal conjugate vaccine administration

BackgroundA prior 7- and 13-valent pneumococcal conjugate vaccine (PCV7 and PCV13) study provided sufficient data (N = 1754; Jewish, n = 1154; Bedouin, n = 595; other, n = 5) to investigate the association between nasopharyngeal (NP) acquisition of common PCV7 serotypes and cross-reacting 6A (PCV7 + 6A) and IgG concentrations.MethodsUsing a logistic regression model, serotype specific association between postinfant series IgG concentration (age 7 months) and new NP acquisition between ages 7 and 24 months was assessed and adjusted for ethnicity. From a subset of subjects with new NP acquisition (n = 9–152 across serotypes studied), new acquisition percentiles and associated IgG concentrations were calculated.ResultsFor the serotypes studied, new NP acquisition rates decreased as IgG concentrations increased. Ethnicity did not influence these associations despite differences in carriage rates. From the subset with new acquisitions, 50% of the events occurred at IgG concentrations >0.61–5.58 μg/mL; and 10% of the acquisitions occurred at IgG concentrations >2.48–17.69 μg/mL.ConclusionRemarkably high IgG concentrations are required to reduce NP acquisition. These IgG concentrations differ between serotypes. Ethnicity did not influence the association between high IgG concentrations and prevention of carriage despite differences in carriage rates. Since carriage determines transmission, these results may have important implications for herd protection.Trial registration: ClinicalTrials.gov number, NCT00508742; http://clinicaltrials.gov/ct2/show/NCT00508742     

Prevalence of middle ear abnormalities from otitis media in relation with pneumococcal vaccine use in the Inuit population of Nunavik,province of Quebec,Canada

BackgroundOtitis media (OM) constitutes an important public health problem in the Inuit population of Nunavik, Northern Quebec. One of the objectives of the childhood pneumococcal vaccination program is to reduce OM burden. The program was implemented in 2002, and 7-, 10-, and 13-valent conjugate vaccines were used sequentially, with doses offered at 2, 4, 6 and 12–18 months, respectively.ObjectiveTo assess the prevalence of middle ear abnormalities at age 5 years in relation with exposure to different pneumococcal conjugate vaccines.MethodsImmunization cards and audiology screening tests at age 5 years of children born in 1994–2010 were reviewed. Children were classified according to the vaccine schedule recommended for their birth cohort or to the vaccines they actually received. Log-linked binomial regression models were used to assess the relative abnormalities risk according to different vaccination schedules.ResultsAmong 3517 children with complete documentation, the prevalences of minor and major abnormalities were 29% and 18%, respectively. Minor abnormalities frequency was higher in unvaccinated children (34%) and lower in children vaccinated with PCV7 (22%), PCV7 + PCV10 (17%), PCV10 (15%) and PCV10 + PCV13 (18%). No substantial differences among vaccine schedules were observed for major abnormalities.ConclusionsPneumococcal conjugate vaccination was associated with a decreased frequency of middle ear abnormalities although no effect was seen for major abnormalities which may be trigger by OM with early onset.Clinicaltrials.gov registration number: NCT01694329