The widely used nasally-administered Live Attenuated Influenza Vaccine (LAIV) alters the dynamics of naturally occurring nasopharyngeal carriage of Streptococcus pneumoniae in animal models. Using a human experimental model (serotype 6B) we tested two hypotheses: 1) LAIV increased the density of S. pneumoniae in those already colonised; 2) LAIV administration promoted colonisation. Randomised, blinded administration of LAIV or nasal placebo either preceded bacterial inoculation or followed it, separated by a 3-day interval. The presence and density of S. pneumoniae was determined from nasal washes by bacterial culture and PCR. Overall acquisition for bacterial carriage were not altered by prior LAIV administration vs. controls (25/55 [45.5%] vs 24/62 [38.7%] respectively, p=0.46). Transient increase in acquisition was detected in LAIV recipients at day 2 (33/55 [60.0%] vs 25/62 [40.3%] in controls, p=0.03). Bacterial carriage densities were increased approximately 10-fold by day 9 in the LAIV recipients (2.82 vs 1.81 log10 titers, p=0.03). When immunisation followed bacterial acquisition (n=163), LAIV did not change area under the bacterial density-time curve (AUC) at day 14 by conventional microbiology (primary endpoint), but significantly reduced AUC to day 27 by PCR (p=0.03). These studies suggest that LAIV may transiently increase nasopharyngeal density of S. pneumoniae. Transmission effects should therefore be considered in the timing design of vaccine schedules.Trial registrationThe study was registered on EudraCT (2014-004634-26)FundingThe study was funded by the Bill and Melinda Gates Foundation and the UK Medical Research Council.

An immunogenic region of the Borrelia burgdorferi flagellin encompassing amino acids 197-273 and designated 41-G was evaluated as an antigen in an enzyme immunoassay (EIA) for Lyme disease on a routine basis in a reference laboratory. Sera that tested positive for Lyme disease by EIA using 41-G or the whole-cell Borrelia burgdorferi lysate as the antigen were also evaluated by immunoblot for reactivity with Borrelia burgdorferi, and the patient's clinical history was determined retrospectively by a questionnaire distributed to the referring physician. The sensitivity of the 41-G based EIA for the serologic diagnosis of Lyme disease, when compared with that of the Borrelia burgdorferi lysate EIA, was 70% (35 of 50). These data demonstrate that 41-G has utility as an antigen in EIA, although the sensitivity is at present less than that of the assay employing the Borrelia burgdorferi whole-cell lysate.

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This study was designed to evaluate the potential of flow cytometry to measure biomarkers of airways inflammation in the peripheral blood of two cohorts of workers reporting work related respiratory symptoms, who were exposed to different respiratory hazards. Nine bakers exposed to wheat flour and 10 glass bottle manufacturers exposed to a range of irritant chemicals were selected for study. Phenotypic and inducible cell surface markers were measured by flow cytometry. Results were compared with a control population of 58 volunteers reporting no respiratory problems. The bakers showed a significant increase above control values for cell types associated with inflammation; in particular CD3 CD4 cells p 0.005 and CD4 CD25 cells p 0.01 . In contrast, the workers reporting work related respiratory symptoms who were exposed to a range of irritant chemicals showed a different pattern of cell surface lymphocyte markers, with a significant decrease in the total T cell population p 0.05 . Comparison of results from a subset of smoking controls with the population of bakers who were all heavy smokers confirmed that the increase in CD3 CD4 cells and CD4 CD25 cells could not be ascribed to the effects of smoking alone. We have shown activation of helper T cells in the peripheral blood of bakers reporting work related respiratory symptoms consistent with the changes observed in mild to severe asthmatics. However, workers with similar symptoms who were exposed to irritant chemicals did not show this pattern of phenotypic or inducible cell surface markers, reflecting an absence of airways inflammation in these individuals. Our results suggest that flow cytometry may be of use as an objective test for detecting workers with airways inflammation to allow the identification of workers at risk of developing occupational asthma.