Table 5.
Sources, respective companies, and approval status of various COVID-19 vaccines.
| Company | Type | Doses | Route | Efficacy | Storage | Approval/Development | Mechanism of Action |
|---|---|---|---|---|---|---|---|
| Pfizer–BioNTech | Nucleoside modified mRNA (BNT162a1 and BNT162b2) | 2 shots 21 days apart |
I.M inj. | 95% | −70 °C | UK approved | Spike proteins and RBD fragments are introduced into the body producing the desired immune response [71]. |
| Oxford–AstraZeneca | Viral vector (genetically altered nonreplicating chimpanzee adenovirus) | 2 shots 4 to 12 weeks apart |
I.M inj. | 70% | Regular fridge temperature | UK approved | Specifically deliver genes to the target cells thus providing a trigger to cytotoxic T-cells resulting in killing of infected cells [69]. |
| Moderna | Based on lipid nanoparticle-encapsulated mRNA | 2 shots 28 days apart |
I.M inj. | 94.1% | −20 °C | UK approved | Encodes stable form of spike protein of SARS-CoV-2 and educates CD4+ immune cells of the body [72]. |
| Novavax (NVX-CoV2373) | Full-length S (spike) Protein-based | 2 | I.M inj. | Regular fridge temperature | Pending | Promotes migration of leukocytes into lymph nodes thus increasing T-cell, B-cell, and NK cell response [69]. | |
| Janssen (Johnson & Johnson’s) | Viral vector based using adenovirus or pox virus | 1 | I.M inj. | 66.3% | Regular fridge temperature | Pending | DNA of the adenovirus is modified which helps the body to develop humoral and T-cell based cellular immune response against COVID-19 [73]. |
| CoronaVac (Sinopharm/Sinovac) (BBIBP-CorV) | Inactivated virus vaccine | I.M inj. | 79% | Regular fridge temperature | Approved by China, Singapore, Saudi Arabia, and Pakistan | Contains virus has been inactivated through UV light/chemicals and elicits antigen-specific antibody response producing plasma cells, T-cells, and memory B-cells [74]. | |
| CanSino Bioloics (Ad5-nCoV) Convidecia | Non-replicating adenovirus based vaccine | 1 | I.M inj. | 66% to 91% | Regular fridge temperature | Approved by Hungary, China, Mexico, and Pakistan | RBD and spike proteins produce T cell response conferring immunity against virus [69]. |
| Sputnik V | Using two non-replicating adenovirus based vector (Ad26, Ad5) | 2 doses 21 days apart | Undergoing phase 3 trials | Gamaleya Institute, Moscow. | Dose 1 injects Ad26, and in dose 2 Ad5 is given. This produces an enhanced immune response [69]. | ||
| KBP-201 (NCT04473690) | Protein (RBD-based) subunit vaccine | 2 doses 21 days apart | I.M inj. | Currently undergoing phase II trials | - | Pending | RBD in the spike protein binds to ACE-2 receptor producing neutralizing monoclonal antibodies towards SARS-CoV-2 [75]. |
| Covaxin | Inactivated virus vaccine | Currently undergoing trials in India | Same as mentioned above under CoronaVac (sinopharm) | ||||
| BHPIV3/SARS-S | Live attenuated virus vaccine | 1 | I.M. Inj | Currently undergoing phase 2 animal trials | Currently undergoing trials in India and China | Induces production of SARS-CoV neutralizing serum antibodies [69]. | |
| DelNS1-SARS-CoV2-RBD | Live attenuated vaccine with deletion of NS1 influenza strain | 1 | Intra-nasal | Currently undergoing phase 2 animal trials | Modified to include SARS-CoV-2 spike protein and is considered more immunogenic than other LAVs [69]. | ||
| LUNAR-COV19 | Lipid enabled and unlocked nucleomonomer agent-modified RNA (LUNAR) | 1 | Currently undergoing phase 1 and 2 trials | Biospace, Singapore | Entry into host cells and mRNA is translated into protiein, s leading to the production of the immune response against SARS-CoV-2 [69]. |
I.M inj. (Intramuscular injection).