Scenario on development of vaccine to combat COVID-19

COVID-19 is ever increasing pandemic in global scenario. The spread of this pandemic is beyond control. Every citizen of the world is now desperately waiting for the reliable measure to get rid out of this global emergency. Majority of researchers working in different continent of the world are trying to reach for a common solution to stop this pandemic. In the context of South Asian continent, infection of COVID-19 has not achieved its plateau yet and has affected large section of population. The main effective way to prevent this dire situation is vaccine development which is safe, efficacious and efficient in preventing the disease. According to WHO, as of date 18 June, 2020, 13 candidate vaccines were in clinical evaluation and 128 candidate vaccines were in pre-clinical evaluation. As of 7th July, 2020, clinical evaluation of the candidate vaccine had reached to 21. Similarly, 139 candidate vaccines were in pre-clinical evaluation. This show that the vaccines trials are in its race for testing its safety and efficacy. There are three clinical phases in vaccine development viz. Phase I, Phase II and Phase III. In Phase I, testing of vaccines is done in 10-100 healthy volunteers for the safety of vaccines. Similarly, Phase II deals with 100-1000 volunteers for considering its safety and adverse events associated with the vaccine administration. If the vaccines meets the requirement of Phase II trials, it will be promoted to Phase III in which 1000-10000 people will be tested for safety and efficacy of the vaccine. After successful clinical evaluation, license will be provided for the vaccines followed by manufacture and distribution. However, safety and efficacy testing will go side by side (Phase IV) after clinical trials. The race for vaccine development started after the publish of nucleotide sequence of the SARS-CoV-2 in January, 2020. Majority of the vaccines are still in pre-clinical trails that means they are being tested in laboratory animal models for their safety and efficacy. These candidate vaccines under development are based on latest technology such as DNA vaccine, RNA vaccine, Recombinant technology and Nano-based vaccine. Some of the undergoing clinical trials under clinical evaluation are cited below.

Table 1 Table showing current vaccine candidates under clinical trial around the world to combat COVID-19

Candidate	Developer	Current Status	Reference
1. AZD1222 (ChAdOx1-S)	University of Oxford/AstraZeneca	Phase III	www.isrctn.com/ISRCTN89951424
2. Ad5-nCoV	Can Sino Biologicals	Phase II	https://clinicaltrials.gov/ct2/show/NCT04313127
3. Inactivated	Sinovac	Phase III	https://clinicaltrials.gov/ct2/show/NCT04456595
4. mRNA-1273	Moderna	Phase II	https://clinicaltrials.gov/ct2/show/NCT04313127
5. LV-SMENP-DC	Shenzhen Geno-Immune Medical Institute	Phase I/II	https://clinicaltrials.gov/ct2/show/NCT04276896
6. Pathogen specific artificial antigen presenting cell (aAPC)	Shenzhen Geno-Immune Medical Institute	Phase I	https://clinicaltrials.gov/ct2/show/NCT04299724
7. INO-4800	Inovio Pharmaceuticals	Phase I/II	https://clinicaltrials.gov/ct2/show/NCT04447781
8. Full length recombinant SARS CoV-2 glycoprotein nanoparticle vaccine adjuvanted with Matrix M	Novavax	Phase I/II	https://clinicaltrials.gov/ct2/show/NCT04368988
9. 3 LNP-mRNAs	BioNTech/Fosun Pharma/Pfizer	Phase I/II	https://clinicaltrials.gov/ct2/show/NCT04368728
10. Adeno-based	Gamaleya Research Institute	Phase I	https://clinicaltrials.gov/ct2/show/NCT04436471
11. DNA plasmid vaccine	Cadila Healthcare Limited	Phase I/II	http://ctri.nic.in/Clinicaltrials
12. Inactivated vaccine	Wuhan Institute of Biological Products/Sinopharm	Phase I/II	http://www.chictr.org.cn/showprojen.aspx?proj=52227
13. Inactivated vaccine	Beijing Institute of Biological Products/Sinopharm	Phase I/II	http://www.chictr.org.cn/showproj.aspx?proj=53003
14. DNA Vaccine (GX-19)	Genexine Consortium	Phase I	https://clinicaltrials.gov/ct2/show/NCT04445389
15. Inactivated vaccine	Institute of Medical Biology, Chinese Academy of Medical Sciences	Phase I	http://www.chictr.org.cn/showproj.aspx?proj=53003
16.Protein Subunit	Clover Biopharmaceuticals Inc./GSK/Dynavax	Phase I	https://clinicaltrials.gov/ct2/show/NCT04405908
17.Protein Subunit	Anhui Zhifei Longcom Biopharmaceutical/ Institute of Microbiology, Chinese Academy of Sciences	Phase I	https://clinicaltrials.gov/ct2/show/NCT04445194
18.Protein Subunit	Vaxine Pty Ltd/Medytox	Phase I	https://clinicaltrials.gov/ct2/show/NCT04453852
19.LNP-nCoVsaRNA	Imperial College London	Phase I	http://www.isrctn.com/ISRCTN17072692
20.mRNA	Curevac	Phase I	https://clinicaltrials.gov/ct2/show/NCT04449276
21. Plant-derived VLP	Medicago Inc./ Université Laval	Phase I	https://clinicaltrials.gov/ct2/show/NCT04450004 (not yet recruiting)

Table 2 Table showing characteristics of vaccines to combat COVID-19

Candidate	Characteristics
Ad5-nCoV	Adenovirus type 5 vector that expresses S protein of SARS-CoV-2
mRNA-1273	mRNA-1273 is a novel lipid nanoparticle (LNP)-encapsulated mRNA-based vaccine that encodes for a full-length, prefusion stabilized spike (S) protein of SARS-CoV-2.
LV-SMENP-DC	Modification of dendritic cells (DC) with lentivirus vectors expressing Covid-19 minigene SMENP and immune modulatory genes. Cytotoxic T-Lymphocytes (CTLs) will be activated by LV-DC presenting Covid-19 specific antigens.
Pathogen specific artificial antigen presenting cell (aAPC)	aAPCs modified with lentiviral vector expressing synthetic minigene based on domains of selected viral proteins
INO-4800	DNA plasmid encoding S protein delivered by electroporation using CELLECTRA® 2000 device
AZD1222 (formerly called as ChAdOx1-S)	Non-Replicating Viral Vector
Full length recombinant SARS CoV-2 glycoprotein nanoparticle vaccine adjuvanted with Matrix M	Protein Subunit
3 LNP-mRNAs	RNA
Adeno-based	Non-Replicating Viral Vector
Inactivated	Inactivated+alum

Last Updated: July 11, 2020
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