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Research and Development for COVID-19 Vaccines
Published in Srijan Goswami, Chiranjeeb Dey, COVID-19 and SARS-CoV-2, 2022
Srijan Goswami, Ushmita Gupta Bakshi
AstraZeneca-Oxford University. The manufacturing process for the AstraZeneca-Oxford University vaccine involves the production of a virus, the adenovirus, which carries the genetic material to the cells inside the body. To produce this virus in the laboratory, a “host” cell line is needed. For some vaccines, chicken cells are used for this process, and for others, human cell lines are used to produce the virus. The Oxford-AstraZeneca vaccine uses a cell line called HEK-293 cells. HEK-293 is the name given to a specific line of cells used in various scientific applications. The original cells were taken from the kidney of a legally aborted fetus in 1973. HEK-293 cells used nowadays are clones of those original cells but are not themselves the cells of the aborted fetus. Each dose of the vaccine (0.5 ml) is known to contain the COVID-19 vaccine (ChAdOx1-S recombinant) 5 × 1010 viral particles (vp), and recombinant, replication-deficient chimpanzee adenovirus vector encoding the SARS-CoV-2 spike (S) glycoprotein (AstraZeneca, 2021; Oxford Vaccine Group 2020, 2021).
Vaccine Development Strategies and the Current Status of COVID-19 Vaccines
Published in Debmalya Barh, Kenneth Lundstrom, COVID-19, 2022
Mohsen Akbarian, Kenneth Lundstrom, Elrashdy M. Redwan, Vladimir N. Uversky
In early April 2020, massive sequencing of the SARS-CoV-2 genome from hundreds of thousands of patients began in the UK. Analysis of these data identified a new SARS-CoV-2 variant VUI 202012/01 (B.1.1.7.), which carries 17 genetic changes [50]. Recent studies have shown that this new variant, while more transmissible, does not have a higher mortality rate than the original SARS-CoV-2, and can be neutralized by existing vaccines [56, 57]. Other variants have since been detected in South Africa and Brazil [58]. While the Pfizer/BioNTech (BNT162b2), Moderna (mRNA-1273), and the University of Oxford/AstraZeneca (ChAdOx1 n-Cov19) vaccines have demonstrated efficacy against the UK variant [51], a recent study indicated that the ChAdOx1 n-CoV19 vaccine did not provide protection against mild-to-moderate COVID-19 caused by the South African variant B.1.351 [59]. Therefore, because of the high mutation rate in coronaviruses there is a risk that new variants will spread and hamper the function and efficacy of present vaccines [60]. It is essential to quickly identify new variants and dedicate resources to develop vaccines that would efficiently target new mutations.
AI and Immunology Considerations in Pandemics and SARS-CoV-2 COVID-19
Published in Louis J. Catania, AI for Immunology, 2021
SARS-CoV-2 is an RNA virus which means its genetic material is encoded in RNA. Once the virus is inside our cells, it releases its RNA and making long viral proteins to compromise the immune system (see Life Cycle above). An mRNAcontaining a genetic strip (fragment) of the coronavirus genetic material, and genomic transcription and translation produce copies of the spike proteins which initiate an APC/ TH (T-helper cells) and TC (T-cytotoxic cells) which ultimately produce B cells that produce antibodies that generate spike protein fragments that abort further proliferation of the virus. Success in vaccine trials with mRNA at the 95% levels as of November, 2020 have led to FDA “Emergency Use Authorization” for Pfizer’s BNT162b2 and Moderna’s ChAdOx1 mRNA vaccines with anxious anticipation of their distribution by early 2021.
Effectiveness of mRNA, protein subunit vaccine and viral vectors vaccines against SARS-CoV-2 in people over 18 years old: a systematic review
Published in Expert Review of Vaccines, 2023
Cristian Sandoval, Daniela Guerrero, Joham Muñoz, Karina Godoy, Vanessa Souza-Mello, Jorge Farías
In relation to the efficacy of mRNA, protein subunit vaccines, and viral vector vaccines against SARS-CoV-2, our findings have shown that the vaccines based on mRNA have an efficacy greater than 90% against the symptomatic disease of SARS-CoV-2. In fact, previous studies have found that a two-dose regimen of BNT162b2 and mRNA-1273 was found to be safe and >90% effective against COVID-19 between seven days and six months after the second dose [10,35,37,39,41,45,46]. In addition, the vaccines met both main efficacy endpoints with a greater than 99.99% probability of efficacy [10,45]. Finally, the efficacy of the BNT162b2 vaccine against severe disease with an onset after receiving the first dose was approximately 97% [47]. However, the higher efficacy has been found in men between 18 and 64 years of age after mRNA-1273 vaccination [11]. The efficacy of ChAdOx1 vaccine after two standard-dose was 53.4% after less than 6 weeks’ interval between doses and 65.4% after at least six weeks interval [36]. In addition, ChAdOx1 vaccine efficacy seems to be better when a standard dose is applied after a low dose [36,39]. In relation to ZF2001 vaccination, even if higher neutralizing GMTs have been shown after vaccination, the percentage efficacy has not yet been described [38].
Disproportionality analysis of adverse neurological and psychiatric reactions with the ChAdOx1 (Oxford-AstraZeneca) and BNT162b2 (Pfizer-BioNTech) COVID-19 vaccines in the United Kingdom
Published in Expert Opinion on Drug Safety, 2023
Matilde Otero-Losada, Nikolai Petrovsky, Abdallah Alami, James A. Crispo, Donald Mattison, Francisco Capani, Christopher Goetz, Daniel Krewski, Santiago Perez-Lloret
Differences in the frequency of AEFIs with ChAdOx1 or BNT162b2 vaccines in the UK have been observed [21]. To the best of our knowledge, our study is one of the first attempts to comprehensively analyze the profile of the relatively rare neurological and psychiatric reactions to these vaccines. We observed significant differences in the frequency of some neurological and psychiatric reactions among individuals exposed to ChAdOx1 or BNT162b2. Headaches & migraines, GBS, and paresthesias, tremors, freezing, delirium, hallucinations, nervousness, poor sleep quality, and postural dizziness were all more frequently reported in persons exposed to ChAdOx1. In contrast, Bell’s palsy, facial paralysis, dysgeusia, anxiety, and presyncope or syncope were more frequently reported after BNT162b2 vaccination. As neurological syndromes following ChAdOx1 and BNT162b2 vaccination involved both the central and peripheral nervous systems, we cannot differentiate vaccines regarding the proclivity to affect intra- vs extra-axial neurological vulnerability. Our findings may help to identify potential relationships between certain conditions and the vaccines.
Waning of humoral immunity depending on the types of COVID-19 vaccine
Published in Infectious Diseases, 2023
So Yun Lim, Ji Yeun Kim, Jiwon Jung, Sung-Cheol Yun, Sung-Han Kim
Healthcare workers (HCWs) who received the COVID-19 vaccine and agreed to peripheral blood sampling were enrolled in this study from March to October 2021 in Asan Medical Centre, a tertiary care hospital in Seoul, South Korea. BNT162b2 was distributed to HCWs in direct contact with COVID-19 patients, and ChAdOx1 nCoV-19 (ChAdOx1) to other HCWs, in conformity with Korean government policy. In addition, the mRNA-1273 vaccine was given instead of ChAdOx1 to individuals under 30 because of the thrombosis with thrombocytopenia syndrome (TTS) issue, as recommended by the Korean government. The interval between the second dose and third dose was 3 weeks, 14 weeks, and 4 weeks in BNT162b2, ChAdOx1, and mRNA-1273 respectively. Booster vaccination was given 6 months after the two-dose ChAdOx1 and BNT162b2 vaccines, but 4 months after mRNA-1273. The booster dose of mRNA-1273 was 50ug. All HCWs given two-dose ChAdOx1 received a subsequent booster vaccination with BNT162b2 because of the TTS issue. Blood sampling was scheduled 2 weeks and 3 months after the second dose and booster vaccinations, respectively. This study was reviewed and approved by the Institutional Review Board of Asan Medical Centre (#2021-0170).