Bkv neutralizing antibodies

A monoclonal antibody, preferably a human monoclonal antibody, or antigen-binding fragment or chain thereof, that binds and neutralizes a plurality of BK virus subtypes including at least subtypes I, II and IV, preferably subtypes I, II, III and IV, said antibody having a combination of a heavy chain variable domain (VH) and/or a light chain variable domain (VL) with the six following complementary-determining regions (CDRs):

• a VH-CDR1 comprising, or consisting of, amino acid sequence GFX1X2RX3YX4 (SEQ ID NO:
• 1), wherein X1 is S, T or N, preferably is S;
• X2 is F, I or L, preferably is F or I;
• X3 is S or G;
• and X4 is A or G, preferably is A;
• a VH-CDR2 comprising, or consisting of, amino acid sequence X36X5X37X6GX7X8X9, wherein X36 is L or I, preferably L;
• X5 is N, T, S or R, preferably is N or T;
• X37 is S or A, preferably S;
• X6 is A, S or N, preferably is A or N;
• X7 is V, A or T, preferably is V or A;
• X8 is S or T;
• X9 is T or A, preferably is T;
• a VH-CDR3 comprising, or consisting of, amino acid sequence AX10DRX11X12X13X38LGSEPX14DP (SEQ ID NO:
• 2), wherein X10 is K or R, preferably is K;
• X11 is G, D or N, preferably is G or D;
• X12 is V or A;
• X13 is E or Q, preferably is E;
• X38 is W or H, preferably W;
• X14 is I, F or L, preferably is I or F;
• a VL-CDR1 comprising, or consisting of, amino acid sequence QX15X16X17X18X19Y, wherein X15 is R or S, preferably is R;
• X16 is V or L, preferably is V;
• X17 is S or G, preferably is S;
• X18 is S or N, preferably is S;
• X19 is N or S;
• a VL-CDR2 comprising, or consisting of, amino acid sequence X2MAS, wherein X20 is R, G or D, preferably is R or G;
• and
• a VL-CDR3 comprising, or consisting of, amino acid sequence QQYGSX21PRS (SEQ ID NO:
• 3), wherein X21 is S or P, preferably is S.