Principles and Challenges in anti-COVID-19 Vaccine Development

Abstract

The number of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected patients keeps rising in most of the European countries despite the pandemic precaution measures. The current antiviral and anti-inflammatory therapeutic approaches are only supportive, have limited efficacy, and the prevention in reducing the transmission of SARS-CoV-2 virus is the best hope for public health. It is presumed that an effective vaccination against SARS-CoV-2 infection could mobilize the innate and adaptive immune responses and provide a protection against severe forms of coronavirus disease 2019 (COVID-19) disease. As the race for the effective and safe vaccine has begun, different strategies were introduced. To date, viral vector-based vaccines, genetic vaccines, attenuated vaccines, and protein-based vaccines are the major vaccine types tested in the clinical trials. Over 80 clinical trials have been initiated; however, only 18 vaccines have reached the clinical phase II/III or III, and 4 vaccine candidates are under consideration or have been approved for the use so far. In addition, the protective effect of the off-target vaccines, such as <i>Bacillus</i> Calmette-Guérin and measles vaccine, is being explored in randomized prospective clinical trials with SARS-CoV-2-infected patients. In this review, we discuss the most promising anti-COVID-19 vaccine clinical trials and different vaccination strategies in order to provide more clarity into the ongoing clinical trials.

Cerebral venous sinus thrombosis 2 weeks after the first dose of mRNA SARS-CoV-2 vaccine

“…In Malaysia, extensive measures have been taken to prevent the spread of COVID-19; however, we are dealing with a precarious situation due to the weakening economic growth [ 16 ]. The emergence of a promising anti-COVID-19 vaccine gives a platform of hope that the virus will soon abate [ 15 ]. The national vaccination program started on February 24, 2021 by the Drug Control Authority has approved three vaccines: COVID-19 vaccine AstraZeneca, CoronaVac suspension for injection (Sinovac), and Comirnaty concentrate for injection dispersion (Pfizer/BioNTech).…”

Adverse events following Sinopharm (Vero Cell), the inactivated COVID-19

“…1 Non-pharmacological intervention along with immunization is essential to control the pandemic. [2][3][4] So far, 20 vaccines have been approved for use in different countries and more than 23.5 % of the world population is fully vaccinated. 5,6 As the countries are rolling out vaccines, much concern has been on their adverse reaction.…”

Counting on COVID-19 vaccine: Insights into the current strategies, progress and future challenges

“…The clustering of antigenic epitopes on the surface of the non-infective particles provides scopes for cognate activation of B cells and enhanced antibody response. Once administered, the antisense RNA inhibits virus expression whereas viral nucleic acid activates pattern recognition receptors to trigger immune responses against the virus characterized by elevated interferons and some proinflammatory cytokines [48]. The safety profile is almost unquestionable since they are devoid of any genetic material.…”