TECHNOLOGIES FOR PREVENTING OR TREATING INFECTIONS

1 . An agent having the structure of:

or a pharmaceutically acceptable salt thereof, wherein:

the agent inhibits, kills, or removes a cell infected by SARS-CoV-2

each of a and b is 1;

A is chosen from ABT, AT, and PT;

ABT is an antibody binding moiety that has the structure: R c -(Xaa)z- or

wherein t is an integer from 1 to 20, and z is an integer from 1 to 50;

AT is an antibody moiety that is immunoglobulin G (IgG), a derivative of IgG, pooled IgG, or intravenous immune globulin (IVIG);

PT is independently a partner moiety selected from a diagnostic agent or detectablemoiety;

L is a linker moiety;

each Xaa is independently an amino acid or an amino acid analog;

y is 5-50;

R CN and R CC are independently R C ;

each R C is independently -L a -R′;

each L a is independently a covalent bond, or an optionally substituted bivalent group selected from C 1 -C 50 aliphatic or C 1 -C 50 heteroaliphatic having 1-5 heteroatoms, wherein one or more methylene units of the aliphatic or heteroaliphatic group are optionally and independently replaced with —C(R′) 2 —, —C y —, —O—, —S—, —S—S—, —N(R′)—, —C(O)—, —C(S)—, —C(NR′)—, —C(O)N(R′)—, —N(R′)C(O)N(R′)—, —N(R′)C(O)O—, —S(O)—, —S(O) 2 —, —S(O) 2 N(R′)—, —C(O)S—, or —C(O)O—;

each —C y — is independently an optionally substituted bivalent monocyclic, bicyclic-, or polycyclic group, wherein each monocyclic ring is independently selected from a C 3-20 cycloaliphatic ring, a C 6-20 aryl ring, a 5-20 membered heteroaryl ring having 1-10 heteroatoms, and a 3-20 membered heterocyclyl ring having 1-10 heteroatoms;

each R′ is independently -R, —C(O)R, —CO 2 R, or —SO 2 R; and

each R is independently —H, or an optionally substituted group selected from C 1-30 aliphatic, C 1-30 heteroaliphatic having 1-10 heteroatoms, C 6-30 aryl, C 6-30 arylaliphatic, C 6-30 arylheteroaliphatic having 1-10 heteroatoms, 5-30 membered heteroaryl having 1-10 heteroatoms, and 3-30 membered heterocyclyl having 1-10 heteroatoms, or

two R groups are optionally and independently taken together to form a covalent bond, or

two or more R groups on the same atom are optionally and independently taken together with the atom they are attached to form an optionally substituted, 3-30 membered, monocyclic, bicyclic or polycyclic ring having, in addition to the atom, 0-10 heteroatoms; or

two or more R groups on two or more atoms are optionally and independently taken together with their intervening atoms to form an optionally substituted, 3-30 membered, monocyclic, bicyclic, or polycyclic ring having, in addition to the intervening atoms, 0-10 heteroatoms;

wherein -(Xaa)y- is or comprises:

-(Xaa T0 )y0-(Xaa T1 )y1-Xaa T2 -(Xaa T3 )y3-Xaa T4 -(Xaa T5 )y5-(Xaa T6 )y6-(Xaa T7 )y7-(Xaa T8 )y8-Xaa T9 -(Xaa T10 )y10-(Xaa T11 )y11-(Xaa T12 )y12-, wherein:

y0 is an integer from 0 to 20;

each Xaa T0 is independently an amino acid or an amino acid analog;

y1 is 0, 1, or 2;

each Xaa T1 is independently an amino acid or an amino acid analog;

Xaa T2 is an amino acid or an amino acid analog whose side chain comprises 3 or more non-hydrogen atoms;

y3 is an integer from 0 to 10;

each of Xaa T3 is independently an amino acid or an amino acid analog;

each of Xaa T4 and Xaa T9 is independently an amino acid or an amino acid analog, wherein Xaa T4 is optionally connected to Xaa T9 through a linker;

y5 is an integer from 0 to 10;

each Xaa T5 is independently an amino acid or an amino acid analog;

y6 is 0, 1, or 2;

each Xaa T6 is independently an amino acid or an amino acid analog;

y7 is 0 or 144;

Xaa T7 is a negatively-charged amino acid or a negatively charged amino acid analog;

y8 is an integer from 0 to 10;

each Xaa T8 is independently an amino acid or an amino acid analog;

y10 is an integer from 0 to 10;

each of Xaa T10 is independently an amino acid or an amino acid analog;

y11 is 1, 2, 3, 4, or 5;

each Xaa T11 is independently an amino acid or an amino acid analog;

y12 is an integer from 0 to 20;

each Xaa T12 is independently an amino acid or an amino acid analog.

2 . The agent of claim 1 , wherein each of Xaa T0 , Xaa T1 , Xaa T2 , Xaa T3 , Xaa T4 , Xaa T5 , Xaa T6 , Xaa T7 , Xaa T8 , Xaa T9 , Xaa T10 , Xaa T11 , and Xaa T12 is independently an amino acid having the structure of formula A-I:

or a salt thereof, wherein:

\each of R a1 , R a2 , and R a3 is independently —L a —R′;

each of L a1 and L a2 is independently L a ;

\\each L a is independently a covalent bond, or an optionally substituted bivalent group selected from C 1 -C 20 aliphatic or C 1 -C 20 heteroaliphatic having 1-5 heteroatoms, wherein one or more methylene units of the aliphatic or heteroaliphatic group are optionally and independently replaced with —C(R′) 2 —, —C y —, —O—, —S—, —S—S—, —N(R′)—, —C(O)—, —C(S)—, —C(NR′)—, —C(O)N(R′)—, —N(R′)C(O)N(R′)—, —N(R′)C(O)O—, —S(O)—, —S(O) 2 —, —S(O) 2 N(R′)—, —C(O)S—, or —C(O)O—;

each —C y — is independently an optionally substituted bivalent monocyclic, bicyclic, or polycyclic group, wherein each monocyclic ring is independently selected from a C 3-20 cycloaliphatic ring, a C 6-20 aryl ring, a 5-20 membered heteroaryl ring having 1-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus and silicon, and a 3-20 membered heterocyclyl ring having 1-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus and silicon;

each R′ is independently -R, —C(O)R, —CO 2 R, or —SO 2 R; and

each R is independently —H, or an optionally substituted group selected from C 1-30 aliphatic, C 1-30 heteroaliphatic having 1-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus and silicon, C 6-30 aryl, C 6-30 arylaliphatic, C 6-30 arylheteroaliphatic having 1-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus and silicon, 5-30 membered heteroaryl having 1-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus and silicon, and 3-30 membered heterocyclyl having 1-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus and silicon, or

two R groups are optionally and independently taken together to form a covalent bond, or-=

two or more R groups on the same atom are optionally and independently taken together with the atom to form an optionally substituted, 3-30 membered, monocyclic, bicyclic or polycyclic ring having, in addition to the atom, 0-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus and silicon; or

two or more R groups on two or more atoms are optionally and independently taken together with their intervening atoms to form an optionally substituted, 3-30 membered, monocyclic, bicyclic or polycyclic ring having, in addition to the intervening atoms, 0-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus and silicon.

3 . The agent of claim 2 , wherein

y0 is 0, y1 is 1 or 2; and -(Xaa T1 )y1- is or comprises a dipeptide or an amino acid that is suitable for forming a turn;

-Xaa T2 - is or comprises an amino acid having the structure of formula A-I, wherein R a2 is hydrophobic, neutral or negatively charged and is a group —L a —R′, wherein L a is an optionally substituted bivalent group selected from C 3 -C 10 aliphatic or C 3 -C 10 heteroaliphatic having 1-5 heteroatoms, wherein one or more methylene units of the group are optionally and independently replaced with —C(R′) 2 —, —O—, —S—, —N(R′)—, —C(O)—, —C(S)—, —C(NR′)—, —S(O)—, or S(O) 2 —;

y3 is 1-10;

Xaa T4 is connected to Xaa T9 through a linker, wherein the linker is L a and is bonded to a backbone carbon atom of Xaa T4 and a backbone carbon atom of Xaa T9; wherein L a is or comprises —CH 2 —CH 2 —, —O—, —S— or —S—S—;

-(Xaa T5 )y5- is or comprises YNK and -(Xaa T5 )y5- is connected to an antibody moiety or an antibody binding moiety optionally through a linker bound to the lysine (K) amino acid in -(Xaa T5 )y5;

y5 is 0 and-(Xaa T6 )y6- is or comprises a D-Ser;

y6 is 1or 2;

y7 is 1 and comprises —COOH or y7 is 0;

-(Xaa T8 )y8- is or comprises GTI or -G-Xaa T8 -IT-Xaa T8 -, wherein each Xaa T8 is independently an alpha amino acid;

y10 is 3 or 4;

-(Xaa T11 )y11- is or comprises L-Ala, D-Ala, Aib, Gly, or negatively charged; or

a combination thereof.

4 . The agent of claim 1 , wherein

y1 is 0;

-(Xaa T1 )y1- is or comprises L-proline, D-proline, a proline derivative, L-serine, D-serine, glycine, L-pseudoproline, or D-psuedoproline; -(Xaa T1 )y1- is or comprises an amino acid having the structure of formula A-I wherein R a1 and R a2 are taken together with their intervening atoms to form an optionally substituted, saturated or partially unsaturated, 3-6 membered, monocyclic or bicyclic ring having, in addition to the intervening atoms, 0-1 heteroatoms selected from oxygen, nitrogen, and sulfur: or

-(Xaa T1 )y1- is or comprises a L-proline.

5 – 9 . (canceled)

10 . The agent of claim 3 wherein L a is —CH 2 —CH 2 —CH 2 —, or —CH 2 —O—CH 2 —, or —CH 2 —S—CH 2 —, R′ is optionally substituted phenyl, or a combination thereof.

11 – 17 . (canceled)

18 . The agent of claim 1 , wherein

-(Xaa T6 )y6- is or comprises a dipeptide or an amino acid that is suitable for forming a turn;

-(Xaa T6 )y6- is or comprises L-proline, D-proline, a proline derivative, L-serine, D-serine, glycine, L-pseudoproline, or D-psuedoproline:

-(Xaa T6 )y6- is or comprises an amino acid that comprises or is further substituted with —L a —COOH; or

a combination thereof.

19 – 30 . (canceled)

31 . The agent of claim 1 , wherein

-(Xaa T1 )y1- is or comprises

-Xaa T2 - is

-(Xaa T2 )y2- is or comprises AVAD; -(Xaa T3 )y3- is or comprises TF, TFLL, or TFLLKY; XAA T4 is Cys;

-(Xaa T6 )y6- is or comprises a D-Ser,

-(Xaa T6 )y6- is or comprises has the structure

Xaa T7 is D or E:

-(Xaa T8 )y8- is or comprises GTI-Xaa T8 -;

Xaa T4 and Xaa T9 are independently Cys and form a disulfide bond —S—S—;

-(Xaa T10 )y10- is or comprises AV; or

a combination thereof.

32 – 33 . (canceled)

34 . The agent of claim 1 , wherein.

-(Xaa)y- is or comprises IEEQAKTFLDKFNHEAEDLFYQS;

-(Xaa)y- is or comprises DISGINASVVNIQKEIDRLNEVAKNLNESLIDLQEL, or a fragment thereof;

-(Xaa)y- is or comprises a sequence selected from, or a sequence designed based on a sequence selected from: Number Sequence

P1

FKLPLGIN(K)ITNFRAILTAFS(L)|

P2

PTT(K)FMLKYDENGTITDAVDC

P3

VLYNSTP(S)FSTFKCYGVSATK

P4

PALNCYWPLN(K)DYGFYTTSGI

P5

RDVSDP(I)TDSVRDPKTSEILD

P6

YQDVNCTDVS(P)TAIHADQLTP

P7

SNNTIAIPTNFS(L)ISITTEVM

P8

OYGSFCT(A)QLNRALSGIAA(V)EQ

P9

GIGVT(A)QNVLYENQKQIANQF

P10

IQK(E)EIDRLNEVAKNLNESLI

-(Xaa)y- is or comprises

.

35 – 36 . (canceled)

37 . The agent of claim 1 , wherein -(Xaa)y- is or comprises.

38 – 39 . (canceled)

40 . The agent of claim 1 , wherein the linker moiety comprises one or more —[(CH 2 ) 2 —O] m — groups, wherein m is an integer from 7 to 12.

41 – 42 . (canceled)

43 . The agent of claim 1 , wherein the agent comprises a single A that is an antibody binding moiety.

44 . (canceled)

45 . The agent of claim 1 , wherein the antibody binding moiety comprises or has the structure selected from A-1 to A-50 or

the antibody binding moiety comprises or has the amino acid sequence DCAWHLGELVWCT, wherein the two cystein amino acids are linked by a —S—S—.

46 . The agent of claim 1 , wherein the agent has the structure

or a salt thereof;

or a salt thereof;

or a salt thereof; ;or

, or a salt thereof.

47 . The agent of claim 1 , wherein the agent has the structure of

or a salt thereof;

or a salt thereof;

(I-11) or a salt thereof;

or a salt thereof;

or a salt thereof;

or a salt thereof;

or a salt thereof;

(I-11) or a salt thereof;

(I-29) or a salt thereof;

(I-31), or a salt thereof;

(I-32), or a salt thereof;

(I-33), or a salt thereof; or

(I-34), or a salt thereof.

48 - 72 . (canceled)

73 . An agent having any of the following structures or a salt thereof.

74 – 75 . (canceled)

76 . A pharmaceutical composition, comprising an agent of claim 1 , or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.

77 . (canceled)

78 . A method for treating a condition, disorder or disease associated with SARS-CoV-2 infection, comprising administering to a subject suffering therefrom an effective amount of an agent or a composition of claim 1 .

79 . A method for inducing, promoting, encouraging, enhancing, triggering, or generating an immune response toward SARS-CoV-2, comprising administering to a subject infected thereby an effective amount of agent or a composition of claim 1 .

80 . The method of claim 78 , wherein the effective amount is an amount sufficient to

(i) induce or generate ADCC or ADCP toward SARS-CoV-2;

(ii) induce or generate long-term immunity toward SARS-CoV-2; or

(iii) provide memory T and/or B cells against SARS-CoV-2 in the subject.

81 . The method of claim 78 , further comprising administering a population of immune cells, wherein the population of immune cells comprises NK cells, selected from allogeneic NK cells, peripheral blood-derived NK cells, MG4101 NK cells, CB-NK NK cells, and cord blood-derived NK cells).

82 . (canceled)

83 . The agent of claim 1 , wherein the agent has the structure:.

84 . The agent of claim 1 , wherein the agent has the structure:.