Emergence of new SARS-CoV-2 Variant of Concern Omicron (B.1.1.529) - highlights Africa's research capabilities, but exposes major knowledge gaps, inequities of vaccine distribution, inadequacies in global COVID-19 response and control efforts

Nearly two years since the start of the SARS-CoV-2 pandemic, which has caused over 5 million deaths, the world continues to be on high COVID-19 alert. The World Health Organization (WHO), in collaboration with national authorities, public health institutions and scientists have been closely monitoring and assessing the evolution of SARS-CoV-2 since January 2020 (WHO 2021a; WHO 2021b). The emergence of specific SARS-CoV-2 variants were characterised as Variant of Interest (VOI) and Variant of Concern (VOC), to prioritise global monitoring and research, and to inform the ongoing global response to the COVID-19 pandemic. The WHO and its international sequencing networks continuously monitor SARS-CoV-2 mutations and inform countries about any changes that may be needed to respond to the variant, and prevent its spread where feasible. Multiple variants of the virus have emerged and become dominant in many countries since January 2021, with the Alpha, Beta, Gamma and Delta variants being the most prominent to date. (Table 1)

Immunomodulatory role for membrane vesicles released by THP-1 macrophages and respiratory pathogens during macrophage infection

Background: During infection, inflammation is partially driven by the release of mediators which facilitate intercellular communication. Amongst these mediators are small membrane vesicles (MVs) that can be released by both host cells and Gram-negative and -positive bacteria. Bacterial membrane vesicles are known to exert immuno-modulatory and -stimulatory actions. Moreover, it has been proposed that host cell-derived vesicles, released during infection, also have immunostimulatory properties. In this study, we assessed the release and activity of host cell-derived and bacterial MVs during the first hours following infection of THP-1 macrophages with the common respiratory pathogens non-typeable Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae, and Pseudomonas aeruginosa. Results: Using a combination of flow cytometry, tunable resistive pulse sensing (TRPS)-based analysis and electron microscopy, we demonstrated that the release of MVs occurs by both host cells and bacteria during infection. MVs released during infection and bacterial culture were found to induce a strong pro-inflammatory response by naive THP-1 macrophages. Yet, these MVs were also found to induce tolerance of host cells to secondary immunogenic stimuli and to enhance bacterial adherence and the number of intracellular bacteria. Conclusions: Bacterial MVs may play a dual role during infection, as they can both trigger and dampen immune responses thereby contributing to immune defence and bacterial survival

O050 Hypersomnolence in children: the diagnostic dilemma

Abstract Background Excessive daytime sleepiness (EDS) is reported to affect up to 20% of pre-pubertal children and 50% of adolescents. EDS can be due narcolepsy and idiopathic hypersomnolence (IH). Currently diagnosis is by a multiple sleep latency test (MSLT) with protocols adapted from adults. The aim of this study was to describe the results of MSLTs in a paediatric population and assess whether a 5th nap altered diagnosis. Methods Retrospective analysis of 253 MSLTs at a single tertiary paediatric centre from May 2004 – Jan 2021 with consent obtained in 214 patients. Narcolepsy defined as a mean sleep latency (MSL) &amp;lt;8min with ≥2 sleep onset REM (SOREM). IH defined as a MSL &amp;lt; 8 minutes with &amp;lt;2 SOREMs. Results outside these parameters were grouped as hypersomnolence not otherwise specified (HNOS), with ambiguous HNOS defined as MSL 8–12 minutes or ≥2 SOREM. Progress to date There were 108 (50%) females, 132 (62%) &amp;gt;12 years old (range 3.3–19.4 years) and 17 patients had repeat studies. Narcolepsy was diagnosed in 48 (22%) and IH in 22 (10%). Criteria for ambiguous HNOS were met by 43 (20%) patients including 11 (5%) with MSL &amp;gt;12 minutes with ≥2 SOREMs. A 5th nap was performed in 58 (27%) MSLTs which did not change the diagnosis. Obstructive sleep apnoea was diagnosed in 48 (22%) patients and 27 (13%) had elevated periodic limb movement index. Intended outcome and impact Applying current MLST criteria in children may significantly under-estimate diagnostic categories for paediatric EDS as evidenced by the ambiguous HNOS. </jats:sec

Analysis of line positions of the ν<SUB>6</SUB> band of <SUP>35</SUP>ClNO<SUB>2</SUB> around 411 cm<SUP>-1</SUP>

International audienceThe first investigation of the ν6 band of the 35ClNO2 isotopic species of nitryl chloride, located at 410.11824 (± 0.00007) cm-1 has been performed using a high resolution (0.00102 cm-1) Fourier transform spectrum recorded at the SOLEIL synchrotron source. This B-type band is rather weak but a long optical path was used and, during the spectrum recording, the nitryl chloride sample was kept at low temperature (221 K) in the optical cell. In this way, the rather strong ν2-ν3 difference band located at 422.6 cm-1, observed at 296 K during a previous investigation of the far infrared region [Orphal J, Morillon-Chapey M, Klee S, Mellau GC, Winnewisser M. J Mol Spectrosc 1998;190:101-6], and interfering with observation, could be strongly reduced. This first assignment of the ν6 band of 35ClNO2 was pursued up to high J and Ka quantum number values, J = 79 and Ka = 37. The ν6 band (expected to be of B-type) has a clearly unusual line intensity pattern, since the P branch is about twice as strong as the R-branch. Since the (weak) ν6 band is located close by to the strong A-type ν3 band located at 370 cm-1 [Anantharajah A, Kwabia Tchana F, Manceron L, Orphal J, Flaud JM. J Quant Spectrosc Radiat Transf 2020; 253:107,078], one could reasonably expect that the ν6 band borrows part of its intensity through the existence of a C-type Coriolis resonance that couples together the 61 ⇔ 31 interacting energy levels. However, during the 61 energy level computation, we could not evidence such resonance, and only a classical Watson's type A-type reduced rotational Hamiltonian, involving a single upper state, was used for this calculation

New analysis of line positions of the ν3 bands of 35ClNO2 and 37ClNO2 around 370 cm−1

International audienceA new investigation of the ν3 bands of 35ClNO2 and 37 ClNO2, located around 370 cm−1 has been performed using a high resolution (0.00102 cm−1) Fourier transform spectrum recorded at SOLEIL with highly improved experimental conditions as compared to previous work [Orphal J, Morillon-Chapey M, Klee S, Mellau GC, Winnewisser M. J Mol Spectrosc 1998;190:101–6]: (i) the use of synchrotron radiation which resulted in a better signal-to-noise ratio; (ii) a resolution twice better; (iii) a low temperature (221 K) with an optical path length of 8.16 m, allowing low pressure (0.025 hPa) in the sample leading to a well resolved spectrum. As a consequence, significantly better results than previously were obtained. Thanks to the new experimental conditions, the line assignments were pursued up to higher J and Ka quantum number values, J = 83 and Ka = 44. For both isotopomers, a total of 6331 transitions were reproduced with a root-mean-square deviation of 2 × 10−4 cm−1 using a Watson-type A-reduced Hamiltonian. Improved rotational and centrifugal distortion constants for the ν3 fundamental bands of 35ClNO2 and 37 ClNO2 have been determined. The band centers are 370.1510773(92) cm−1 for the ν3 fundamental band of 35ClNO2 and 364.5218094(96) cm−1 for the ν3 fundamental band of 37ClNO2. The synthetic line list obtained in this study could be interesting for future measurements of ClNO2 in the atmosphere, e.g. using the new space mission FORUM which is one of the concepts chosen by ESA to be developed further and which opens up a new window (150–1400 cm−1 ) for understanding and quantifying the radiative processes, as well as air quality and pollution effect

Integrated band intensities and absorption cross sections of phosgene (Cl2CO) in the mid-infrared at 199, 250 and 300 K

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High-resolution analysis of the 12.6 µm spectral region of the nitryl chloride ClNO2 molecule

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