Beyond their substantial protection of individual vaccinees, coronavirus disease 2019 (COVID-19) vaccines might reduce viral load in breakthrough infection and thereby further suppress onward transmission. In this analysis of a real-world dataset of positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test results after inoculation with the BNT162b2 messenger RNA vaccine, we found that the viral load was substantially reduced for infections occurring 12-37 d after the first dose of vaccine. These reduced viral loads hint at a potentially lower infectiousness, further contributing to vaccine effect on virus spread.The recently authorized BNT162b2 Coronavirus Disease 2019 (COVID-19) messenger RNA (mRNA) vaccine is approximately 95% efficient in preventing polymerase chain reaction (PCR)-confirmed symptomatic disease from 7 d after the second dose and also provides some early protection starting 12 d after the first dose 1,2 . As countries race to vaccinate a substantial portion of their populations in the coming months, it is hoped that the basic reproduction number of the virus will decrease. This effect can be achieved by reducing the number of susceptible people, as well as by reducing viral load and, thereby, viral shedding of post-vaccination infections, which might render them less infectious [3][4][5][6][7] . However, the effect of vaccination on viral load in COVID-19 post-vaccination infections is currently unknown 8 .As of February 11, 2021, Maccabi Healthcare Services (MHS) in Israel has vaccinated more than 1 million of its members as part of a national rapid rollout of the vaccine. MHS member SARS-CoV-2 tests are often carried out in the MHS central laboratory, which offers the opportunity to track post-vaccination infections. In this study, we retrospectively collected and analyzed the quantitative reverse transcription PCR (RT-qPCR) test measurements of three SARS-CoV-2 genes-E, N and RdRp (Allplex 2019-nCoV assay, Seegene)-from positive post-vaccination tests performed at the MHS central laboratory between December 21, 2020, and February 11, 2021 (n = 4,938 patients, study population; Table 1). The study period was characterized by high and steady rates of positive COVID-19 tests (Extended Data Fig. 1), indicating an ongoing epidemic wave.In an analysis of the infection cycle threshold (Ct) over time, we found that the mean viral load substantially decreased 12 d after vaccination with the first vaccine dose, coinciding with the known early onset of vaccine-mediated protection 1 . When we calculated the mean Ct for post-vaccination infections identified on each day
Serum calcium levels are usually only mildly elevated during pregnancy in women with PHPT. A significant proportion of cases go undiagnosed. Mild hypercalcemia in gestational PHPT is generally not associated with an increased risk of obstetrical complications.
Binding studies using the enantiomers of the synthetic cannabinoid 7-hydroxy-A'-tetrahydrocannabinol 1,1-dimethylheptyl homolog in preparations of rat brain cortical membranes reveal that the (+)-(3S,4S) enantiomer HU-211 blocks N-methyl-D-aspartate (NMDA) receptors in a stereospecific manner and that the interaction occurs at binding sites distinct from those of other noncompetitive NMDA antagonists or of glutamate and glycine. Moreover, HU-211 induces stereotypy and locomotor hyperactivity in mice and tachycardia in rat, effects typically caused by NMDA receptor antagonists. HU-211 is also a potent blocker of NMDA-induced tremor, seizures, and lethality in mice. This compound may therefore prove useful as a nonpsychoactive drug that protects against NMDA-receptor-mediated neurotoxicity.The enantiomers of the synthetic cannabinoid 7-hydroxy-A6-tetrahydrocannabinol 1,1-dimethylheptyl homolog have recently been described (1, 2). The (-)-(3R,4R) enantiomer, code-named HU-210 ( Fig. 1), is a highly potent cannabimimetic compound (-80 times more active than &1-tetrahydrocannabinol, the active component of hashish); the (+)-(3S,4S) enantiomer (code-named HU-211) (Fig. 1) is inactive as a cannabimimetic, even at doses several thousand times higher than the ED50 of HU-210 as assayed in a number of tests (2). In characterizing the drug profile of the nonpsychotropic (+) enantiomer HU-211, we noted a striking similarity between its pharmacological, autonomic, and behavioral effects and those of noncompetitive N-methyl-D-aspartate (NMDA) antagonists over a wide range of activities (including stereotypy, locomotor hyperactivity, and tachycardia). This similarity suggested that HU-211 might be functionally active as an NMDA-receptor antagonist. To explore the action of HU-211 and its interaction with specific receptors in the brain, we conducted both pharmacological experiments and binding studies. MATERIALS AND METHODS 3H-labeled N-[1-(2-thienyl)-cyclohexyl]piperidine ([3H]TCP)(40 Ci/mmol; 1 Ci = 37 GBq; >98% pure) was purchased from the Israel Nuclear Center (Negev, Israel). L-Glutamate and glycine were from Sigma; D-(-)-2-amino-5-phosphonovaleric acid (AP-5) and NMDA were from Cambridge Research Biochemicals (Harston, U.K.). HU-211 and HU-210 were synthesized as described (1). Both enantiomers melt at 140-141°C and have identical IR and NMR spectra. administration and tested 60 min after injection. Locomotor hyperactivity was measured as body displacement over 7-cm squares, movement from one square to the next constituting a score of 1. This movement was independently assessed by three trained observers.Heart rate measured over 75 min was determined by the standard transducer-amplifier-recorder technique, and respiratory frequency was visually observed by three trained independent observers with a very high meter-rater correlation. Tremor and seizure were monitored on a platform mounted on four spring-coils. Any vibration of the platform was transduced into an electrical input to an amplifer and then to an osci...
Beyond their substantial protection of individual vaccinees, it is hoped that the COVID-19 vaccines would reduce viral load in breakthrough infections thereby further suppress onward transmission. Here, analyzing positive SARS-CoV-2 test results following inoculation with the BNT162b2 mRNA vaccine, we find that the viral load is reduced 4-fold for infections occurring 12-28 days after the first dose of vaccine. These reduced viral loads hint to lower infectiousness, further contributing to vaccine impact on virus spread.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.