Chandan Sarkar :
The pandemic of coronavirus disease 2019 (COVID-19) caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) presents an unprecedented challenge for the researchers to offer safe, tolerable, and effective treatment strategies for prevention and treatment. Current therapeutic options include – conventional drugs, vaccine or convalescent plasma therapy.
It is the greatest challengeable for the rapid identification of effective therapy developmental technologies and interventions for the COVID-19 associated paramount global public health crisis. Compared with other viral infection, SARS-CoV-2 causes high pro-inflammatory disease state associated with COVID-19 through inducing lower levels of IFN-I and -III expression with a moderate reaction of IFN-stimulated genes (ISGs) and raising chemokine expression.
In the development of an ideal vaccine candidate, it is necessary to maintain 3R standards: replacement, reduction, and refinement.There are mainly two stages for the development of a new vaccine candidate. The first stageis the preclinical stage involving the in vitro (human tissues and cell lines) and in vivo (animal models) experimental methods. The second stage is human testing and includes FDA (US) and EMA (Europe) approvals. This stage is divided into 3 phases: -(i) phase 1 testing on tens of people can take several months, (ii) phase 2 testing on hundreds of people can take from several months to 2 years, and (iii) phases 3/4 testing on thousands of people can take from 1 to 4 years.
Still now, only 10 vaccine candidates are skipped the preclinical stage and began to be administered directly to human subjects in different phases: ChAdOx1 nCoV-19 vaccine (non-replicating viral vector based vaccine) developed by the University of Oxford, Ad5-nCoV vaccine (vector based vaccine) developed byCanSino Biologics Inc., mRNA-1273 vaccine (mRNA vaccine)developed by ModernaTX Inc., BNT162 vaccine (mRNA vaccine) developed by Biontech SE,INO-4800 vaccine (DNA plasmid based vaccine) developed by Inovio Pharmaceuticals, Inc., SARS-CoV-2 rS vaccine (pathogenic fragments based) developed by Novavax, Inc., LV-SMENP-DC (modified dendritic cells with lentivirus vectors-based vaccine) developed by Shenzhen Geno-Immune Medical Institute and another three inactivated vaccine developed by Wuhan Institute of Biological Products, by Beijing Institute of Biological Products co., Ltd., and by Sinovac Research and Development co., Ltd.
According to official data presented by the WHO, the current situation of the candidate vaccines for COVID-19 is as follows: Inovio is expected to complete the first phase of the study in November 2020, CanSino in December 2020, Moderna in June 2021, Biontech SE in January 2023, Sinovac in July 2020, Novavax in July 2021, and Shenzhen only in July 2023. The University of Oxford expected to complete the phase 2/3study in August 2021.
So, assuming that all is well, DNA technology gives lasting immunity without side effects, Inovio could have a product approved somewhere in June 2021. For all other officially vaccinated candidates, the deadline is sometime in 2022 or 2023, possibly long after we have naturally acquired herd immunity.
(Chandan Sarkar is a M. Pharm Student at Department of Pharmacy, Bangabandhu Sheikh Mujibur Rahman Science and Technology University. E-mail: [email protected])
