Table 1 Binding affinities of the prototype, Delta, and Omicron RBDs with ACE2 orthologs from different species.

Human

16.1 ± 1.46

21.5 ± 1.49

18.2 ± 1.33

Monkey

22 ± 4.16

16.53 ± 0.17

8.32 ± 0.53

Rabbit

48.13 ± 2.09

58.27 ± 3.40

27.27 ± 4.11

Mouse

–

–

14.23 ± 6.22

Rat

–

–

2993.33 ± 941.71

Guinea pig

–

–

–

Malayan pangolin

35.17 ± 6.53

58.2 ± 1.04

5026.67 ± 2284.39

Cat

99.05 ± 5.95

53.35 ± 7.05

24.2 ± 1.13

Civet

–

–

1147.33 ± 134.86

Fox

56.2 ± 1.53

35.65 ± 5.75

35.5 ± 6.71

Dog

100.63 ± 4.50

51.43 ± 3.90

491 ± 177.81

Raccoon dog

80 ± 5.11

124 ± 9.20

109.70 ± 20.00

Mink

305 ± 16.08

288 ± 5.12

11.88 ± 2.59

Horse

220.67 ± 20.80

78.97 ± 4.83

5893.33 ± 1208.87

Pig

138.67 ± 13.30

64.37 ± 5.70

321.33 ± 39.42

Wild Bactrian camel

103.5 ± 16.95

233 ± 20.40

38.23 ± 13.25

Alpaca

11798.53 ± 1224.84

381.35 ± 14.83

26.05 ± 2.07

Bovine

181 ± 13

71.35 ± 5.85

39.5 ± 6.94

Goat

213.5 ± 6.5

66.25 ± 0.35

126.47 ± 34.14

Sheep

174 ± 1

60.95 ± 2.35

75.13 ± 11.38

Least horseshoe bat

–

–

189.5 ± 24.5

Big-eared horseshoe bat

677.1 ± 83.87

49.56 ± 2.91

1840.22 ± 425.90

Fulvous fruit bat

156.67 ± 34.31

200.33 ± 31.85

>37700

Greater horseshoe Bat

–

–

12078 ± 677.43

Chinese horseshoe bat

–

–

–

Little brown bat

129.67 ± 23.70

185.67 ± 22.95

>55366.67

Lesser hedgehog tenrec

–

–

>29070