Research progress and challenges to coronavirus vaccine development

Abstract

Coronaviruses (CoVs) are nonsegmented, single-stranded, positive-sense RNA viruses highly pathogenic to humans. Some CoVs are known to cause respiratory and intestinal diseases, posing a threat to the global public health. Against this backdrop, it is of critical importance to develop safe and effective vaccines against these CoVs. This review discusses human vaccine candidates in any stage of development and explores the viral characteristics, molecular epidemiology, and immunology associated with CoV vaccine development. At present, there are many obstacles and challenges to vaccine research and development, including the lack of knowledge about virus transmission, pathogenesis, and immune response, absence of the most appropriate animal models. K E Y W O R D S animal model, coronavirus, receptor-binding domain, spike protein, vaccine 1 | INTRODUCTION Coronaviruses (CoVs) are a large family of viruses with some causing mild to moderate illnesses like the common cold and others bringing severe diseases such as Middle East respiratory syndrome coronavirus (MERS-CoV) and severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV). At the end of 2019, emerging infections caused by a novel CoV were reported in Wuhan, China. Most of the early reported cases came from the South China Seafood Wholesale Market in Wuhan, China, which is now closed and disinfected. The virus was identified as a new CoV and officially named by The International Committee on Taxonomy of Viruses as SARS-CoV-2 (previously provisionally named 2019 novel coronavirus or 2019-nCoV by World Health Organization [WHO]), and the disease caused by SARS-CoV-2 received its official name as COVID-19 later on February 11, 2020. 1 As of July 29, 2020, there were 16,341,920 confirmed COVID-19 cases worldwide, including 650,805 deaths. According to the WHO, 226,783 new cases and 4153 new deaths worldwide in the last 24 h. 2 Since the beginning of the new millennium, the rapid emergence and spread of CoVs have caused a grave loss of life and property. One of the most famous examples is the SARS-CoV, which first appeared during the winter of 2002 and caused a viral respiratory illness, namely the SARS. 3,4 The SARS epidemic had serious consequences in 29 regions and countries, with 8096 people being infected worldwide and the mortality rate reaching 9.6%. 5 Later in 2012, the MERS-CoV was first identified in a 60-year-old man who lived in the Kingdom of

Inadvertent Human Mucosal Exposure to SARS-CoV-2 Recombinant S1 Protein Elicits Immunity

“…The global effort to tackle the current COVID-19 pandemic has led to an unprecedented number of novel clinical vaccine candidates from public and private organizations, including several in late stage clinical trials and two receiving FDA Emergency Use Authorization (1). Such rapid vaccine development was enabled by innovative technologies and discoveries made in response to recent outbreaks in the new millenium including SARS, MERS, and the West Africa and Democratic Republic of the Congo Ebola epidemics (2,3) as well as more recent federal investments in development and manufacturing.…”

“…Instead-particularly in the setting of an active, deadly pandemic-the rational strategy is to extrapolate from related diseases and err for maximization of e cacy (3,5). The trade-offs of this approach may include immunogenicity, manufacturability, stability/supply-chain/last mile, cost, global access, safety, and public trust (3,(5)(6). In addition, target selection may be suboptimal due to the accelerated timelines and lack of available early data.…”

Recent drugs and vaccines candidates to tackle COVID-19

“…In numerous patients, COVID-19 infection is associated with a cytokine storm [30][31][32][33][34][35]. In this case, coronavirus patients will encounter serious lung complications and it can also lead to death and in recovered cases, the excessive immune responses lead to long-term lung damage and fibrosis [36,37].…”

From the environment to the cells: An overview on pivotal factors which affect spreading and infection in COVID-19 pandemic

“…Vaccines are the most effective medical tool against infectious diseases, and they not only prevent or ameliorate the disease severity but also reduce the transmission of the pathogens and decrease the mutation rate of the viruses in pandemics (P. Zhou et al, 2021 ).…”