Project description:Given the interest in the COVID mRNA vaccines, we sought to investigate how the RNA modification N1-methylpseudouridine (and its related modification, pseudouridine) is read by ribosomes and reverse transcriptases. By looking at reverse transcriptase data, we can gain information on how the modification affects duplex stability, which may have important consequences for the tRNA-mRNA interactions found in the ribosome.
Project description:COVID-19 is a pandemic of unprecedented proportions in recent human history. Less than 18 months since the onset of the pandemic, there are close to two hundred million confirmed cases and four million deaths worldwide. There have also been massive efforts geared towards finding safe and effective vaccines. By July 2021 there were 184 COVID-19 vaccine candidates in pre-clinical development, 105 in clinical development, and 18 vaccines approved for emergency use by at least one regulatory authority. These vaccines include whole virus live attenuated or inactivated, protein-based, viral vector, and nucleic acid vaccines. By mid-2021 three billion doses of COVID-19 vaccine have been administered around the world, mostly in high-income countries. COVID-19 vaccination provides hope for an end to the pandemic, if and only if there would be equal access and optimal uptake in all countries around the world.
Project description:This article is a narrative review of the rapidly moving coronavirus disease 2019 vaccine field with an emphasis on clinical efficacy established in both randomized trials and postmarketing surveillance of clinically available vaccines. We review the major clinical trials that supported authorization for general use of the Janssen (Ad.26.CoV2), Pfizer-BioNTech (BNT162b2), and Moderna (mRNA-1273) vaccines and the publicly available postmarketing information with the goal of providing a broad, clinically relevant comparison of efficacy and safety. This review is primarily focused on the US market.
Project description:Memory T and B cells in lymphoid and mucosal tissues maintain long-term protection, though their generation following vaccination remains challenging to assess in humans. Here, we investigated immune memory generated to COVID-19 mRNA vaccines across blood, lymphoid organs, and lungs from 42 vaccinated organ donors aged 23-86, of whom 57% were previously infected with SARS-CoV-2. Using high-dimensional profiling, we reveal that Spike (S)-reactive memory T cells distribute in lymphoid organs and lungs, variably express tissue resident markers based on infection history, and exhibit site-specific compositions of effector and regulatory memory T cells. S-reactive B cells are mostly class-switched memory cells localized to lymphoid organs correlating with circulating antibodies. Importantly, tissue memory T cells are more stably maintained post-vaccination and over age and exhibit a bias towards regulatory cell functional profiles compared to circulating populations. Our results show that mRNA vaccines can induce heterogeneous memory populations across sites for protection and controlling immune pathology.
Project description:The ongoing COVID-19 pandemic and its unprecedented global societal and economic disruptive impact highlight the urgent need for safe and effective vaccines. Taking substantial advantages of versatility and rapid development, two mRNA vaccines against COVID-19 have completed late-stage clinical assessment at an unprecedented speed and reported positive results. In this review, we outline keynotes in mRNA vaccine development, discuss recently published data on COVID-19 mRNA vaccine candidates, focusing on those in clinical trials and analyze future potential challenges.
Project description:Since the emergence of COVID-19, caused by the SARS-CoV-2 virus at the end of 2019, there has been an explosion of vaccine development. By 24 September 2020, a staggering number of vaccines (more than 200) had started preclinical development, of which 43 had entered clinical trials, including some approaches that have not previously been licensed for human vaccines. Vaccines have been widely considered as part of the exit strategy to enable the return to previous patterns of working, schooling and socializing. Importantly, to effectively control the COVID-19 pandemic, production needs to be scaled-up from a small number of preclinical doses to enough filled vials to immunize the world's population, which requires close engagement with manufacturers and regulators. It will require a global effort to control the virus, necessitating equitable access for all countries to effective vaccines. This review explores the immune responses required to protect against SARS-CoV-2 and the potential for vaccine-induced immunopathology. We describe the profile of the different platforms and the advantages and disadvantages of each approach. The review also addresses the critical steps between promising preclinical leads and manufacturing at scale. The issues faced during this pandemic and the platforms being developed to address it will be invaluable for future outbreak control. Nine months after the outbreak began we are at a point where preclinical and early clinical data are being generated for the vaccines; an overview of this important area will help our understanding of the next phases.
Project description:The COVID mRNA vaccines utilize the modified nucleobase N1-methylpseudouridine, in place of canonical uridine, to improve immunogenicity and protein yield. However, relatively few studies have investigated the effect of modified nucleobases on the fidelity of protein translation. Given the interest in the COVID mRNA vaccines, we sought to investigate how N1-methylpseudouridine (and the related modification pseudouridine) is read by ribosomes.
Project description:The worldwide pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to the unprecedented pace of development of multiple vaccines. This review evaluates how adenovirus (Ad) vector platforms have been leveraged in response to this pandemic. Ad vectors have been used in the past for vaccines against other viruses, most notably HIV and Ebola, but they never have been produced, distributed, or administered to humans at such a large scale. Several different serotypes of Ads encoding SARS-CoV-2 Spike have been tested and found to be efficacious against COVID-19. As vaccine rollouts continue and the number of people receiving these vaccines increases, we will continue to learn about this vaccine platform for COVID-19 prevention and control.