Progress and Pitfalls in the Quest for Effective SARS-CoV-2 (COVID-19) Vaccines

Abstract

There are currently around 200 SARS-CoV-2 candidate vaccines in preclinical and clinical trials throughout the world. The various candidates employ a range of vaccine strategies including some novel approaches. Currently, the goal is to prove that they are safe and immunogenic in humans (phase 1/2 studies) with several now advancing into phase 2 and 3 trials to demonstrate efficacy and gather comprehensive data on safety. It is highly likely that many vaccines will be shown to stimulate antibody and T cell responses in healthy individuals and have an acceptable safety profile, but the key will be to confirm that they protect against COVID-19. There is much hope that SARS-CoV-2 vaccines will be rolled out to the entire world to contain the pandemic and avert its most damaging impacts. However, in all likelihood this will initially require a targeted approach toward key vulnerable groups. Collaborative efforts are underway to ensure manufacturing can occur at the unprecedented scale and speed required to immunize billions of people. Ensuring deployment also occurs equitably across the globe will be critical. Careful evaluation and ongoing surveillance for safety will be required to address theoretical concerns regarding immune enhancement seen in previous contexts. Herein, we review the current knowledge about the immune response to this novel virus as it pertains to the design of effective and safe SARS-CoV-2 vaccines and the range of novel and established approaches to vaccine development being taken. We provide details of some of the frontrunner vaccines and discuss potential issues including adverse effects, scale-up and delivery.

Mandatory preoperative SARS-CoV-2 infection screening policies for paediatric surgery

“…As a result, false negatives should be expected and preoperative clinical screening for COVID-19 should be routinely performed. Lastly, even if promising recent vaccine trial results lead to worldwide durable immunity, preventive and social strategies to be employed in a timely fashion to reduce community spread, morbidity and mortality ( 7 , 8 ), and to protect the medical and nursing community at large.…”

COVID-19 and Dentistry in 72 Questions: An Overview of the Literature

“…World Health Organization maintains a landscape document referencing the candidate vaccines in development [341], available at: https://www.who.int/publications/m/item/draft-landscape-of-covid-19-candidate-vaccines Q42-Which are the various strategies to design vaccines to protect against SARS-CoV-2 infection? [81,[342][343][344] Several vaccine platforms are under development and include:…”

Antibody-Dependent Enhancement of Bacterial Disease: Prevalence, Mechanisms, and Treatment

“…VAERD is a unique clinical syndrome first observed in the 1960s when whole-inactivated viral vaccines for measles and respiratory syncytial virus (RSV) were administered in children (13). Along with aberrant T cell responses (14), the use of a limiting dose or conformationally incorrect antigen in vaccines can result in the production of nonneutralizing antibodies (15). As mentioned previously, this generation of non-neutralising antibodies runs the potential risk of binding pathogenic microorganisms -but not blocking or clearing them -allowing them to replicate or permit formation of immune complexes activating complement pathways associated with several inflammatory disorders (15).…”