Insight into the liver dysfunction in COVID-19 patients: Molecular mechanisms and possible therapeutic strategies

Table 1 Summary of severe acute respiratory syndrome coronavirus 2 strains and mutations that enhance viral entry into the host cell

Sr. No.	Strain	Mutation	Host entry	Location	Time of first report	Ref.
1	Alpha (B.1.1.7)	N501Y mutation on the RBD	The affinity between RBD and ACE2 is significantly increased	United Kingdom	December 2020	[40-42]
2	Beta (B.1.351)	N501Y mutation on the RBD N417/K848/Y501	The affinity between RBD and ACE2 is significantly increased	South Africa	December 2020	[41-43]
3	Gamma (P.1)	N501Y mutation on the RBD N417/K848/Y501	The affinity between RBD and ACE2 is significantly increased	Brazil	January 2021	[41,42,44]
4	Delta (B.1.617.2)	Absence of N501Y mutation	No effect	India	December 2020	[41,42]
5	Omicron (B.1.1.529)	N501Y mutation on the RBD	The affinity between RBD and ACE2 is significantly increased	South Africa	November 2021	[41,42]

RBD: Receptor binding domain; ACE2: Angiotensin-converting enzyme 2.

Table 2 Summary of the effective vaccines developed so far against coronavirus disease 2019

Sr. No.	Name of vaccine	FDA approval	Type of vaccine	Manufactured by	Efficacy	No. of doses	Safety profile	Ref.
1	NVX-CoV2373 vaccine	December 20, 2021	Recombinant SARS-CoV-2 nanoparticle	Novavax	92.6%	2	Safe till date	[105]
2	BNT162b2 vaccine	FDA issued a EUA on December 11, 2020	mRNA-based	BioNTech/Pfizer	95%	2	Safe till date	[106]
3	mRNA-1273 vaccine	FDA issued a EUA on December 18, 2020	mRNA-1273 based	Moderna	94.1%	2	Safe till date	[107]
4	ChAdOx1 nCoV-19 vaccine	Not yet received a EUA or approval from the FDA	Recombinant spike protein vaccine	Serum institute of India, private limited	70.4%	2	Vaccine-induced immune thrombotic thrombocytopenia	[108]
5	Ad26.COV2	EUA by the FDA on February 27, 2021	Recombinant vaccine	Janssen-Cilag International, NV Belgium	73.1%	1	Vaccine-induced immune thrombotic thrombocytopenia	[109]
6	Covaxin	EUA for adults	Whole inactivated virus-based	Bharat Biotech in collaboration with ICMR and NIV, India	64%	2	Safe till date	[110]
7	Sputnik V	EUA qualified	Human adenovirus vector	Russian direct investment fund	97.2%	2	Safe till date	[111]
8	CoronaVac	FDA issued under EUA	Inactivated virus alum-adjuvanted candidate vaccine	Sinovac biotech, China	51% against symptomatic SARS-CoV-2 infection, 100% against severe COVID-19	2	Safe till date	[112]

SARS-CoV-2: Severe acute respiratory syndrome coronavirus 2; COVID-19: Coronavirus disease 2019; FDA: Food and Drug Administration; EUA: Emergency Use Authorization; ICMR: Indian Council of Medical Research; NIV: National Institute of Virology.