An optical waveguide fiber comprising: a core having a radius r 1 in the range 4.8 μm ≤ r 1 ≤ 10 μm and a relative refractive index percent profile Δ 1 (r) in % measured relative to pure silica, said relative refractive index percent profile Δ 1 (r) having a maximum Δ 1MAX in the range -0.15% ≤ Δ 1MAX ≤ 0.2%; a cladding (18,20); a primary coating surrounding and directly adjacent said cladding; and a secondary coating surrounding and directly adjacent to said primary coating; wherein said relative refractive index percent profiles Δ 1 (r) and said primary and secondary coatings are configured such that said optical waveguide fiber exhibits an effective area greater than 130 μm 2 at a wavelength of 1550 nm and a wire mesh drum microbending loss less than 0.4 dB/km at a wavelength of 1550 nm; characterised by said primary coating comprising the cured product of a primary composition that includes an acrylate oligomer, a diacrylate oligomer, or a urethane acrylate oligomer; a monofunctional (meth)acrylate monomer; and a multifunctional (meth)acrylate monomer, the primary coating having an in situ modulus of less than 0.20 MPa and an outer diameter less than 190 μm; and said secondary coating being the cured product of a secondary composition that includes a monomer selected from the group consisting of acrylates, substituted acrylates, alkyl acrylates, alcohol-based acrylates, N-vinyl amides, styrenes, vinyl ethers, vinyl esters, and acid esters, wherein said secondary coating does not include an oligomeric component, and wherein said secondary coating has an in situ modulus of greater than 1500 MPa. a core having a radius r 1 in the range 4.8 μm ≤ r 1 ≤ 10 μm and a relative refractive index percent profile Δ 1 (r) in % measured relative to pure silica, said relative refractive index percent profile Δ 1 (r) having a maximum Δ 1MAX in the range -0.15% ≤ Δ 1MAX ≤ 0.2%; a cladding (18,20); a primary coating surrounding and directly adjacent said cladding; and a secondary coating surrounding and directly adjacent to said primary coating; wherein said relative refractive index percent profiles Δ 1 (r) and said primary and secondary coatings are configured such that said optical waveguide fiber exhibits an effective area greater than 130 μm 2 at a wavelength of 1550 nm and a wire mesh drum microbending loss less than 0.4 dB/km at a wavelength of 1550 nm; characterised by said primary coating comprising the cured product of a primary composition that includes an acrylate oligomer, a diacrylate oligomer, or a urethane acrylate oligomer; a monofunctional (meth)acrylate monomer; and a multifunctional (meth)acrylate monomer, the primary coating having an in situ modulus of less than 0.20 MPa and an outer diameter less than 190 μm; and said secondary coating being the cured product of a secondary composition that includes a monomer selected from the group consisting of acrylates, substituted acrylates, alkyl acrylates, alcohol-based acrylates, N-vinyl amides, styrenes, vinyl ethers, vinyl esters, and acid esters, wherein said secondary coating does not include an oligomeric component, and wherein said secondary coating has an in situ modulus of greater than 1500 MPa.