The new SARS-CoV-2 Omicron variant (B.1.1.529) has been recently declared a Variant of Concern due to a series of important mutations in the viral spike protein and especially in the receptor-binding ...domain. While investigations into the spread of this new variant are ongoing, the first cases have been detected in Switzerland. Important questions have been raised: (1) Will the PCR assays commonly used to detect SARS-CoV-2 still work for the Omicron variant? (2) Can specific PCR features, e.g. S-gene dropout, be used to identify potential Omicron samples? In this minireview we provide current knowledge on the Omicron variant and guidance on its PCR validation.
Brief Report: Zika Virus Infection and Fetal Brain Abnormalities
In this case report, the association between Zika virus infection and teratogenicity is strengthened, with evidence that the latency ...period between ZIKV infection of the fetal brain and the detection of microcephaly and intracranial calcifications on ultrasonography may be prolonged.
Zika virus (ZIKV), a mosquito-borne flavivirus and member of the Flaviviridae family, was originally isolated from a sentinel primate in Uganda in 1947.
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ZIKV was associated with mild febrile disease and maculopapular rash in tropical Africa and some areas of Southeast Asia. Since 2007, ZIKV has caused several outbreaks outside its former distribution area in islands of the Pacific: in 2007 on Yap island in Micronesia, in 2013 and 2014 in French Polynesia, and in 2015 in South America, where ZIKV had not been identified previously.
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There are separate African and Asian lineages of the virus,
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and the latter . . .
The ecology of infectious disease in wildlife has become a pivotal theme in animal and public health. Studies of infectious disease ecology rely on robust surveillance of pathogens in reservoir ...hosts, often based on serology, which is the detection of specific antibodies in the blood and is used to infer infection history. However, serological data can be inaccurate for inference to infection history for a variety of reasons. Two major aspects in any serological test can substantially impact results and interpretation of antibody prevalence data: cross-reactivity and cut-off thresholds used to discriminate positive and negative reactions. Given the ubiquitous use of serology as a tool for surveillance and epidemiological modeling of wildlife diseases, it is imperative to consider the strengths and limitations of serological test methodologies and interpretation of results, particularly when using data that may affect management and policy for the prevention and control of infectious diseases in wildlife. Greater consideration of population age structure and cohort representation, serological test suitability and standardized sample collection protocols can ensure that reliable data are obtained for downstream modeling applications to characterize, and evaluate interventions for, wildlife disease systems.
The cerebral ventricles have been studied since the fourth century BC and were originally thought to harbor the soul and higher executive functions. During the infancy of neuroradiology, alterations ...to the ventricular shape and position on pneumoencephalography and ventriculography were signs of mass effect or volume loss. However, in the current era of high-resolution cross-sectional imaging, variation in ventricular anatomy is more easily detectable and its clinical significance is still being investigated. Interpreting radiologists must be aware of anatomic variations of the ventricular system to prevent mistaking normal variants for pathology. We will review of the anatomy and development of the lateral ventricles and discuss several ventricular variations.
We present a search for anisotropic cosmic birefringence in 500 deg2 of southern sky observed at 150 GHz with the SPTpol camera on the South Pole Telescope. We reconstruct a map of cosmic ...polarization rotation anisotropies using higher-order correlations between the observed cosmic microwave background (CMB) E and B fields. We then measure the angular power spectrum of this map, which is found to be consistent with zero. The nondetection is translated into an upper limit on the amplitude of the scale-invariant cosmic rotation power spectrum, L(L + 1) CααL/2π < 0.10 × 10−4 rad2 (0.033 deg2, 95% C.L.). This upper limit can be used to place constraints on the strength of primordial magnetic fields, B1 Mpc < 17 nG (95% C.L.), and on the coupling constant of the Chern-Simons electromagnetic term gaγ < 4.0 × 10−2/HI (95% C.L.), where HI is the inflationary Hubble scale. For the first time, we also cross-correlate the CMB temperature fluctuations with the reconstructed rotation angle map, a signal expected to be nonvanishing in certain theoretical scenarios, and find no detectable signal. We perform a suite of systematics and consistency checks and find no evidence for contamination.
The roots of most land plants are colonised by mycorrhizal fungi that provide mineral nutrients in exchange for carbon. Here, we show that mycorrhizal mycelia can also act as a conduit for signalling ...between plants, acting as an early warning system for herbivore attack. Insect herbivory causes systemic changes in the production of plant volatiles, particularly methyl salicylate, making bean plants, Vicia faba, repellent to aphids but attractive to aphid enemies such as parasitoids. We demonstrate that these effects can also occur in aphid‐free plants but only when they are connected to aphid‐infested plants via a common mycorrhizal mycelial network. This underground messaging system allows neighbouring plants to invoke herbivore defences before attack. Our findings demonstrate that common mycorrhizal mycelial networks can determine the outcome of multitrophic interactions by communicating information on herbivore attack between plants, thereby influencing the behaviour of both herbivores and their natural enemies.
Induction of antigen-specific CD8(+) T cells offers the prospect of immunization against many infectious diseases, but no subunit vaccine has induced CD8(+) T cells that correlate with efficacy in ...humans. Here we demonstrate that a replication-deficient chimpanzee adenovirus vector followed by a modified vaccinia virus Ankara booster induces exceptionally high frequency T-cell responses (median >2400 SFC/10(6) peripheral blood mononuclear cells) to the liver-stage Plasmodium falciparum malaria antigen ME-TRAP. It induces sterile protective efficacy against heterologous strain sporozoites in three vaccinees (3/14, 21%), and delays time to patency through substantial reduction of liver-stage parasite burden in five more (5/14, 36%), P=0.008 compared with controls. The frequency of monofunctional interferon-γ-producing CD8(+) T cells, but not antibodies, correlates with sterile protection and delay in time to patency (P(corrected)=0.005). Vaccine-induced CD8(+) T cells provide protection against human malaria, suggesting that a major limitation of previous vaccination approaches has been the insufficient magnitude of induced T cells.
Traditionally, vaccine development against the blood-stage of Plasmodium falciparum infection has focused on recombinant protein-adjuvant formulations in order to induce high-titer growth-inhibitory ...antibody responses. However, to date no such vaccine encoding a blood-stage antigen(s) alone has induced significant protective efficacy against erythrocytic-stage infection in a pre-specified primary endpoint of a Phase IIa/b clinical trial designed to assess vaccine efficacy. Cell-mediated responses, acting in conjunction with functional antibodies, may be necessary for immunity against blood-stage P. falciparum. The development of a vaccine that could induce both cell-mediated and humoral immune responses would enable important proof-of-concept efficacy studies to be undertaken to address this question.
We conducted a Phase Ia, non-randomized clinical trial in 16 healthy, malaria-naïve adults of the chimpanzee adenovirus 63 (ChAd63) and modified vaccinia virus Ankara (MVA) replication-deficient viral vectored vaccines encoding two alleles (3D7 and FVO) of the P. falciparum blood-stage malaria antigen; apical membrane antigen 1 (AMA1). ChAd63-MVA AMA1 administered in a heterologous prime-boost regime was shown to be safe and immunogenic, inducing high-level T cell responses to both alleles 3D7 (median 2036 SFU/million PBMC) and FVO (median 1539 SFU/million PBMC), with a mixed CD4(+)/CD8(+) phenotype, as well as substantial AMA1-specific serum IgG responses (medians of 49 µg/mL and 41 µg/mL for 3D7 and FVO AMA1 respectively) that demonstrated growth inhibitory activity in vitro.
ChAd63-MVA is a safe and highly immunogenic delivery platform for both alleles of the AMA1 antigen in humans which warrants further efficacy testing. ChAd63-MVA is a promising heterologous prime-boost vaccine strategy that could be applied to numerous other diseases where strong cellular and humoral immune responses are required for protection.
ClinicalTrials.gov NCT01095055.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The induction of cellular immunity, in conjunction with antibodies, may be essential for vaccines to protect against blood-stage infection with the human malaria parasite Plasmodium falciparum. We ...have shown that prime-boost delivery of P. falciparum blood-stage antigens by chimpanzee adenovirus 63 (ChAd63) followed by the attenuated orthopoxvirus MVA is safe and immunogenic in healthy adults. Here, we report on vaccine efficacy against controlled human malaria infection delivered by mosquito bites. The blood-stage malaria vaccines were administered alone, or together (MSP1+AMA1), or with a pre-erythrocytic malaria vaccine candidate (MSP1+ME-TRAP). In this first human use of coadministered ChAd63-MVA regimes, we demonstrate immune interference whereby responses against merozoite surface protein 1 (MSP1) are dominant over apical membrane antigen 1 (AMA1) and ME-TRAP. We also show that induction of strong cellular immunity against MSP1 and AMA1 is safe, but does not impact on parasite growth rates in the blood. In a subset of vaccinated volunteers, a delay in time to diagnosis was observed and sterilizing protection was observed in one volunteer coimmunized with MSP1+AMA1—results consistent with vaccine-induced pre-erythrocytic, rather than blood-stage, immunity. These data call into question the utility of T cell-inducing blood-stage malaria vaccines and suggest that the focus should remain on high-titer antibody induction against susceptible antigen targets.
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