Question to the Department of Health and Social Care:

To ask the Secretary of State for Health and Social Care, pursuant to the Answer 1 December 2025 to Question HL12274 on Visual Snow Syndrome: Yellow Card Scheme, if he will confirm whether official UK drug labels or patient information leaflets warn about the possibility of this condition occurring.

Visual snow syndrome (VSS) was officially recognized in 2025 with a unique code in the eleventh edition of the International Classification of Diseases by the World Health Organization. Very few cases of VSS have been reported with 22 individual drugs or vaccines through the Yellow Card scheme.

VSS is a rare disorder and the underlying cause currently unknown. The Medicines and Healthcare products Regulatory Agency (MHRA) keeps all licensed medicines and vaccines under close monitoring and any potential signal of an association between a medicine or vaccine exposure and development of VSS will be rigorously assessed through the MHRA’s multidisciplinary signal review process and added to individual product information when there is data available to support regulatory action.