Circulation of pertussis and poor protection against diphtheria among middle-aged adults in 18 European countries

Reported incidence of pertussis in the European Union (EU) and the European Economic Area (EEA) varies and may not reflect the real situation, while vaccine-induced protection against diphtheria and tetanus seems sufficient. We aimed to determine the seroprevalence of DTP antibodies in EU/EEA countries within the age groups of 40-49 and 50-59 years. Eighteen countries collected around 500 samples between 2015 and 2018 (N = 10,302) which were analysed for IgG-DTP specific antibodies. The proportion of sera with pertussis toxin antibody levels ≥100 IU/mL, indicative of recent exposure to pertussis was comparable for 13/18 countries, ranging between 2.7-5.8%. For diphtheria the proportion of sera lacking the protective level (</p

rBCG Induces Strong Antigen-Specific T Cell Responses in Rhesus Macaques in a Prime-Boost Setting with an Adenovirus 35 Tuberculosis Vaccine Vector

BACKGROUND: BCG vaccination, combined with adenoviral-delivered boosts, represents a reasonable strategy to augment, broaden and prolong immune protection against tuberculosis (TB). We tested BCG (SSI1331) (in 6 animals, delivered intradermally) and a recombinant (rBCG) AFRO-1 expressing perfringolysin (in 6 animals) followed by two boosts (delivered intramuscullary) with non-replicating adenovirus 35 (rAd35) expressing a fusion protein composed of Ag85A, Ag85B and TB10.4, for the capacity to induce antigen-specific cellular immune responses in rhesus macaques (Macaca mulatta). Control animals received diluent (3 animals). METHODS AND FINDINGS: Cellular immune responses were analyzed longitudinally (12 blood draws for each animal) using intracellular cytokine staining (TNF-alpha, IL-2 and IFN-gamma), T cell proliferation was measured in CD4(+), CD8alpha/beta(+), and CD8alpha/alpha(+) T cell subsets and IFN-gamma production was tested in 7 day PBMC cultures (whole blood cell assay, WBA) using Ag85A, Ag85B, TB10.4 recombinant proteins, PPD or BCG as stimuli. Animals primed with AFRO-1 showed i) increased Ag85B-specific IFN-gamma production in the WBA assay (median >400 pg/ml for 6 animals) one week after the first boost with adenoviral-delivered TB-antigens as compared to animals primed with BCG (<200 pg/ml), ii) stronger T cell proliferation in the CD8alpha/alpha(+) T cell subset (proliferative index 17%) as compared to BCG-primed animals (proliferative index 5% in CD8alpha/alpha(+) T cells). Polyfunctional T cells, defined by IFN-gamma, TNF-alpha and IL-2 production were detected in 2/6 animals primed with AFRO-1 directed against Ag85A/b and TB10.4; 4/6 animals primed with BCG showed a Ag85A/b responses, yet only a single animal exhibited Ag85A/b and TB10.4 reactivity. CONCLUSION: AFRO-1 induces qualitatively and quantitatively different cellular immune responses as compared with BCG in rhesus macaques. Increased IFN-gamma-responses and antigen-specific T cell proliferation in the CD8alpha/alpha+ T cell subset represents a valuable marker for vaccine-take in BCG-based TB vaccine trials

Multilaboratory Comparison of Pneumococcal Multiplex Immunoassays Used in lmmunosurveillance of Streptococcus pneumoniae across Europe

Surveillance studies are required to estimate the impact of pneumococcal vaccination in both children and the elderly across Europe. The World Health Organization (WHO) recommends use of enzyme immunoassays (EIAs) as standard methods for immune surveillance of pneumococcal antibodies. However, as levels of antibodies to multiple serotypes are monitored in thousands of samples, a need for a less laborious and more flexible method has evolved. Fluorescent-bead-based multiplex immunoassays (MIAs) are suitable for this purpose. An increasing number of public health and diagnostic laboratories use MIAs, although the method is not standardized and no international quality assessment scheme exists. The EU Pneumo Multiplex Assay Consortium was initiated in 2013 to advance harmonization of MIAs and to create an international quality assessment scheme. In a multilaboratory comparison organized by the consortium, agreement among nine laboratories that used their own optimized MIA was assessed on a panel of 15 reference sera for 13 pneumococcal serotypes with the new WHO standard 007sp. Agreement was assessed in terms of assay accuracy, reproducibility, repeatability, precision, and bias. The results indicate that the evaluated MIAs are robust and reproducible for measurement of vaccine-induced antibody responses. However, some serotype-specific variability in the results was observed in comparisons of polysaccharides from different sources and of different conjugation methods, especially for serotype 4. On the basis of the results, the consortium has contributed to the harmonization of MIA protocols to improve reliability of immune surveillance of Streptococcus pneumoniae

Responsiveness of human circulating phagocytes in relation to the inflammatory condition

In the early stages of the inflammatory process, monocytes and granulocytes constitute important effector cells that must function correctly in order to clear infection. By activating leukocytes in vitro it is possible to mimic the in vivo activation of these cells and study their activation potential. However, in vitro activation may not tell the entire story: cells that have been exposed to inflammatory mediators in vivo could have an altered response when activated in vitro. The objective of this thesis was to evaluate the functional response, with different activation markers, of peripheral granulocytes and monocytes, in relation to selected inflammatory conditions. Peripheral leukocytes from blood donors are frequently used as control cells in laboratory tests. It is known that blood sampling and separation techniques can affect the quantitative levels of activation markers on leukocytes. In the first study we therefore investigated the influence of two different blood sampling procedures, in a blood donation setting, on peripheral granulocytes. We found that a brief contact with the transfer tube generated an ex vivo activation of peripheral neutrophils probably due to activation of the complement system within the transfer tube. During coronary artery bypass grafting (CABG) a whole body inflammatory response occurs, and the heart-lung machine (CPB) has been thought to be the major contributor to this phenomenon. In the second and third part of this thesis we evaluated the impact of the CP13 on peripheral phagocytes during CABG. Patients were randomised to surgery with (ONCAB) or without (OFFCAB) CPB. We could demonstrate less complement activation in OFFCAB compared to ONCAB patients during and 24 hours after CABG surgery. Despite this finding, both neutrophil and monocyte adhesion molecule expression was similar for both patient groups. The cells responsiveness to in vitro activation was also similar. Neutrophil numbers increased during and after CABG surgery whereas the number of circulating eosinophils decreased considarably. We also found a selective decrease in the numbers of CD14+/CD16+ monocytes during surgery. Both neutrophils and monocytes are activated as a consequence of CABG without apparent additional effects of CPB. The investigated parameters indicate that the surgical trauma could be the most important factor contributing to the enhanced inflammatory response noted during cardiac surgery. In the last part of the study we investigated the systemic influence of a chronic inflammatory condition, namely chronic obstructive pulmonary disease (COPD), on peripheral blood phagocytes. We found that neutrophils, monocytes and eosinophils from both COPD patients and asymptomatic smokers have an impaired oxidative burst in vitro compared to those from non-smokers. In addition patients and smokers also have vascular involvement as determined by elevated levels of sICAM1. There were no differences in adhesion molecule expression or mobilisation between the studied groups although smoking had an acute effect on CD 11 b mobilisation in COPD patients. These findings may in part explain why COPD patients show increased susceptibility to respiratory infections. Taken together, the data presented in this thesis demonstrate the value of monitoring peripheral granulocytes and monocytes during acute and chronic inflammatory disorders. In vitro activation is a helpful tool for examining the responsiveness of circulating phagocytes

B-cell responses after intranasal vaccination with the novel attenuated Bordetella pertussis vaccine strain BPZE1 in a randomized phase I clinical trial

AbstractDespite high vaccination coverage, pertussis is still a global concern in infant morbidity and mortality, and improved pertussis vaccines are needed. A live attenuated Bordetella pertussis strain, named BPZE1, was designed as an intranasal vaccine candidate and has recently been tested in man in a phase I clinical trial. Here, we report the evaluation of the B-cell responses after vaccination with BPZE1. Forty-eight healthy males with no previous pertussis-vaccination were randomized into one of three dose-escalating groups or into a placebo group. Plasma blast- and memory B-cell responses were evaluated by ELISpot against three different pertussis antigens: pertussis toxin, filamentous haemagglutinin and pertactin. Seven out of the 36 subjects who had received the vaccine were colonized by BPZE1, and significant increases in the memory B-cell response were detected against all three tested antigens in the culture-positive subjects between days 0 and 28 post-vaccination. The culture-positive subjects also mounted a significant increase in the filamentous haemagglutinin-specific plasma blast response between days 7 and 14 post-vaccination. No response could be detected in the culture-negatives or in the placebo group post-vaccination. These data show that BPZE1 is immunogenic in humans and is therefore a promising candidate for a novel pertussis vaccine. This trial is registered at ClinicalTrials.gov (NCT01188512)

Pertactin-deficient isolates: evidence of increased circulation in Europe, 1998 to 2015.

IntroductionPertussis outbreaks have occurred in several industrialised countries using acellular pertussis vaccines (ACVs) since the 1990s. High prevalence of pertactin (PRN)-deficien

Surveillance of circulatingBordetella pertussisstrains in Europe during 1998-2015.

One reason for increased pertussis incidence is the adaptation of Bordetella pertussis to vaccine-induced immunity by modulating its genomic structure. This study, EUpert IV, includes 265 isolates collected from nine European countries during 2012 to 2015 (n=265) and compares the results to previous EUpert I-III studies (1998-2009). The analyses included genotyping, serotyping and pulsed-field gel electrophoresis (PFGE) and multi-locus variable-number tandem repeat analysis (MLVA). Genotyping results showed only small variation among the common virulence genes ofB. pertussisFrequencies of serotypes Fim2 and Fim3 varied among the four collections. Genomic analyses showed that MLVA type 27 increased to 80% between the periods of 1998-2001 and 2012-2015. Two PFGE profiles, BpSR3 (29.4%) and BpSR10 (27.2%), constituted more than 50% of the circulating isolates in the present collection. Our study indicates that the EuropeanB. pertussispopulation is changing more homogenous after the introduction of acellular pertussis vaccines

CONSORT Flow Diagram.

<p>Number of subjects assessed for eligibility, enrolled and randomized to study vaccine or placebo. Subjects were included in a step-wise fashion with 16 subjects in each group. Interim safety analysis was performed before vaccination of the next, higher dose group.</p