Potent neutralizing anti-SARS-CoV-2 human antibodies cure infection with SARS-CoV-2 variants in hamster model

Treatment with neutralizing monoclonal antibodies (mAbs) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contributes to COVID-19 management. Unfortunately, SARS-CoV-2 variants can escape several of these recently approved mAbs, highlighting the need for additional discovery and development. In a convalescent COVID-19 patient, we identified six mAbs, classified in four epitope groups, that potently neutralized SARS-CoV-2 Wuhan, alpha, beta, gamma and delta infection in vitro. In hamsters, mAbs 3E6 and 3B8 potently cured infection with SARS-CoV-2 Wuhan, beta and delta when administered post-viral infection at 5 mg/kg. Even at 0.2 mg/kg, 3B8 still reduced viral titers. Intramuscular delivery of DNA-encoded 3B8 resulted in in vivo mAb production of median serum levels up to 90 ug/ml, and protected hamsters against delta infection. Overall, our data mark 3B8 as a promising candidate against COVID-19, and highlight advances in both the identification and gene-based delivery of potent human mAbs.

Epinephrine auto-injector needle length

Background Epinephrine auto-injectors are expected to deliver the drug intramuscularly. Objective To study whether injection through clothing influences the frequency of subcutaneous and intraosseous/periosteal deposition of epinephrine. Methods Skin to muscle and skin to bone distances were measured for 303 children and adolescents and 99 adults. Distance was determined by ultrasound, with high or low pressure on the ultrasound probe. The risk/percentage of subcutaneous and intraosseous/periosteal injections was calculated using the lower and upper limits for the authority-approved length of EAI needles as provided by two high pressure EAI manufacturers and one low pressure EAI manufacturer. The addition winter clothing on the delivery of epinephrine was illustrated by comparing drug delivery fissue depth with no clothes. Furthermore, the riof non-intramuscular delivery for the shortest and longest approved needle length was calculated. Results When using EpipenJr® in children < 15 kg the risk of intraosseous/periostal injection was reduced from 1% and 59% for the shortest and longest approved needle length to 0 and 15% with winter clothes. The Auvi-Q® 0.1 mg had no risk of intraosseous/periosteal injection. However, the subcutaneous deposition risk increased from 94% and 28% to 100% and 99% with winter clothes. The risk of subcutaneous injection using EpipenJr® in the youngest children increased from 13% and 0% to 81% and 1% with winter clothes, and with Epipen® in adults from 45% and 17% to 60% and 38%. Emerade®, had a risk of subcutaneous injection in adults increasing from 14% and 10% to 28% and 21% adding winter clothes. Conclusion The risk of intraosseous/periosteal injections decreases and the risk of subcutaneous injection increases when injecting through winter clothes for all EAIs.

Gene Transfer in Rodent Nervous Tissue Following Hindlimb Intramuscular Delivery of Recombinant Adeno-Associated Virus Serotypes AAV2/6, AAV2/8, and AAV2/9

Recombinant adeno-associated virus (rAAV) vectors have emerged as the safe vehicles of choice for long-term gene transfer in mammalian nervous system. Recombinant adeno-associated virus–mediated localized gene transfer in adult nervous system following direct inoculation, that is, intracerebral or intrathecal, is well documented. However, recombinant adeno-associated virus delivery in defined neuronal populations in adult animals using less-invasive methods as well as avoiding ectopic gene expression following systemic inoculation remain challenging. Harnessing the capability of some recombinant adeno-associated virus serotypes for retrograde transduction may potentially address such limitations (Note: The term retrograde transduction in this manuscript refers to the uptake of injected recombinant adeno-associated virus particles at nerve terminals, retrograde transport, and subsequent transduction of nerve cell soma). In some studies, recombinant adeno-associated virus serotypes 2/6, 2/8, and 2/9 have been shown to exhibit transduction of connected neuroanatomical tracts in adult animals following lower limb intramuscular recombinant adeno-associated virus delivery in a pattern suggestive of retrograde transduction. However, an extensive side-by-side comparison of these serotypes following intramuscular delivery regarding tissue viral load, and the effect of promoter on transgene expression, has not been performed. Hence, we delivered recombinant adeno-associated virus serotypes 2/6, 2/8, or 2/9 encoding enhanced green fluorescent protein (eGFP), under the control of either cytomegalovirus (CMV) or human synapsin (hSyn) promoter, via a single unilateral hindlimb intramuscular injection in the bicep femoris of adult C57BL/6J mice. Four weeks post injection, we quantified viral load and transgene (enhanced green fluorescent protein) expression in muscle and related nervous tissues. Our data show that the select recombinant adeno-associated virus serotypes transduce sciatic nerve and groups of neurons in the dorsal root ganglia on the injected side, indicating that the intramuscular recombinant adeno-associated virus delivery is useful for achieving gene transfer in local neuroanatomical tracts. We also observed sparse recombinant adeno-associated virus viral delivery or eGFP transduction in lumbar spinal cord and a noticeable lack thereof in brain. Therefore, further improvements in recombinant adeno-associated virus design are warranted to achieve efficient widespread retrograde transduction following intramuscular and possibly other peripheral routes of delivery.