New WHO International Biological Reference Standards established following WHO Expert Committee on Biological Standardisation October meeting

On 12-15 October 2026 the WHO held the 83^rd meeting of its Expert Committee for Biological Standardisation (ECBS). During the meeting, MHRA-NIBSC experts presented the results from a number of completed biological standardisation projects, leading to the establishment of 12 new or replacement WHO International Standards or International Reference Reagents, as listed below.

It is anticipated that these products will enter the NIBSC catalogue and be available for purchase in the coming weeks. Check here for updates.

Detailed outcomes of the wider WHO ECBS meeting are available in the executive summary report.

New WHO IBRS

• Ustekinumab, 1^st WHO International Standard (product code 22/114)
• Epidermal growth factor receptor genomic variants (circulating tumour DNA), WHO International Reference Reagent (product code 22/160)
• Antibodies to Monkeypox virus for neutralization assays, 1^st WHO International Standard (product code 22/218_NT)
• Antibodies to Monkeypox virus for binding assays, 1^st WHO International Standard (product code 22/218_BA)
• Antibodies to Vaccinia virus for neutralization assays, 1^st WHO International Standard (product code 05/124_NT)
• Antibodies to Vaccinia virus for binding assays, 1^st WHO International Standard (product code 05/124_BA)
• Antibodies to Shigella flexneri serotypes 2a, 3a, 6 and Shigella sonnei, 1^st WHO International Standard (product code 25/160)
• Antibodies to Shigella flexneri serotypes 2a, 3a, 6 and Shigella sonnei, WHO International Reference Reagent (product code 25/170)

Replacement WHO standards

• Hepatitis B surface antigen, 4^th WHO International Standard (product code 25/120)
• Antibodies to Varicella zoster virus, 2^nd WHO International Standard (product code 25/168)
• Inactivated poliomyelitis vaccine, 4^th International Standard (product code 08-143)
• MRC-5 cells, 3^rd WHO International Reference Cell Bank