TABLE 1.

Key Advantages and disadvantages, and efficacy of approved major COVID‐19 vaccines (vaccines in late developmental phase are also shown, Classic platforms in Yellow and Next generation platforms in blue); Data form various sources

Major groups (Classic or Next generation)	Vaccine platform	Advantages	Disadvantages	Vaccines currently approved and claimed efficacy	Vaccines in late developmental phases
Classic	Live‐Attenuated Virus	Relatively easy and quick to manufacture due to proven technology; safe; provides multivalent antigens and hence may protect against current or future viral variants; no adjuvants required; induce strong immune responses	Requires facilities for live virus handling; inappropriate for immunosuppressed individuals; Rare possibility of reversion and risk for infection; complicated to scale up manufacturing	Nil in the market thus far	Covi‐Vac intranasal vaccine(Codagenix/Serum Institute of India)
Classic	Inactivated virus	Relatively easy and rapid manufacture due to proven technology; provides multivalent antigens and hence may protect against current or future viral variants; no adjuvants required	Complex manufacturing process and hence difficulty to scale up; less reactive (reactogenic) than the live virus vaccines and produces a weaker immune response	Sinovac Vaccine(Sinovac Research and Development Co., Ltd./Butantan Institute) (Efficacy: 52 percent)	QazCovid (Research Institute for Biological Safety Problems, India)
				Sinopharm vaccine(Sinopharm Group, China)(Efficacy: 79 percent)
Classic	Protein/Subunit	Relatively safe as live virus is not used in the actual vaccine manufacture; induces strong cellular and humoral immune responses	High cost; lower immunogenicity to specific proteins/antigens; adjuvants required to increase potency may cause allergic reactions in vaccinees; complicated to scale up the manufacturing process	Novavax, Inc. (Nasdaq: NVAX) NVX‐CoV2373 COVID−19 vaccine(Efficacy: 89.3% in the United Kingdom and 49.4% in South Africa—including HIV‐positive and HIV‐negative subjects)	NVX‐CoV2373 (Novavax, USA).SCB−2019 vaccine (Clover Biopharmaceuticals AUS Pty Ltd.), Covax−19 (GeneCure Biotechnologies; Vaxine Pty Ltd.),
Next generation	Viral Vector‐Based	High degree of safety due to years of proven experience in the gene therapy field; induces strong cellular and humoral responses as they imitate the natural infection; can be stored at 40C (home fridge temperature)	Theoretical risk of infection and/or chromosomal integration and oncogenesis; ineffective in immunocompromised subjects (as most have been pre‐exposed to multiple adenoviruses)	Oxford–AstraZeneca COVID−19 vaccine (AZD1222); AstraZeneca and University of Oxford, UK (Efficacy: 72 percent)	CanSino Biologics.
				Gamaleya (Sputnik V) Research Institute of Epidemiology and Microbiology, Health Ministry of the Russian Federation.(Efficacy: 92 percent)
				Johnson & Johnson; USA(Efficacy: 66–85 percent)
Next generation	mRNA	Safe as no live virus handling during development, rapid development, and production; flexibility to produce multivalent vaccines (in the event of virus variants arising); no risk of genetic integration; induces a very strong immune response	RNA being very fragile require ultra‐cold chain requirements (−700C for Moderna and −20 0 C for Pfizer/Biotec) for storage and transport; currently, high cost; long term adverse effects, if any, unknown	Moderna, Moderna, USA (Efficacy: 95 percent)	CureVac (Bayer and Imperial College London)
				Pfizer‐BioNTec :Europe (synonym: Cominarty) In adults (Efficacy: approx. 95 percent) In children, aged 12–15‐years (Efficacy: 100 percent)
Next generation	DNA	Safe as no live virus handling during development; possibility of multivalency; both humoral and cell‐mediated immune response, good long‐term stability with no cold chain requirements; possibility of freeze drying and storage and transportation at ambient temperatures; oral formulations are feasible	Repeated doses thought to cause toxicity; potential risk of genetic integration unknown	Nil in the market thus far	INO−4800 (International Vaccine Institute; Inovio Pharmaceuticals), Symvivo, Canada ‐COVID19 (AnGes, Inc.); GX−19 (Genexine, Inc.)