Table 1.

Summary of the emerging SARS-CoV-2 ORF3a mutant variants.

Viral variants	Pango* lineage	First detection and location	ORF3a mutations**	Possible mutational effect and reference
Virus of Interest (VOI) ***
Lambda	C.37	Peru, Dec-2020	None	n/a
Mu	B.1.621	Colombia, Jan-2021	Q57H, del256/257	V256/N257 are at a highly conserved region of the C-terminal
Epsilon	B.1.427	California, USA, July 2020	Q57H	It may render stronger binding affinity to S protein than wild-type ORF3a (Wu et al., 2021); also associates with disease severity (Nagy et al., 2021).
Virus of Concern (VOC) ***
Alpha	B.1.1.7	United Kingdom, Sep-2020	None	n/a
Beta	B.1.351	South Africa, May-2020	Q57H, S171L	S171 within β3; see note on Q57H
Gamma	P.1	Brazil, Nov-2020	S253P, D155Y	D155 at junction of β1 and β2 sheets; S253 within a well-conserved C-terminal end
Delta	B.1.617.2	India, Oct-2020	S26L	At the extracellular N-terminal
Omicron	BA.1/B.1.1.529	South Africa Nov-2021	None	n/a (Desingu et al., 2022; Saxena et al., 2022)
	BA.2/B.1.1.529.2	South Africa Nov-2021	T223I	T223I is at junction of β7 and β8 sheets (Desingu et al., 2022; Mahase, 2022)
	BA.3/B.1.1.529.3	South Africa, Nov-2021	T223I	T223I is at junction of β7 and β8 sheets (Desingu et al., 2022)

n/a, not applicable.

^*A phylogenetic name of a distinctive viral variant (Rambaut et al., 2020).

^**Data are from Stanford University Coronavirus Antiviral and Resistance Database (Tzou et al., 2020).

^***VOI and VOC are defined by WHO.