SHIFT Newsroom · UK
RSV vaccine warning puts rare nerve condition in context
The MHRA identified a small Guillain–Barré syndrome risk in older adults while retaining a favourable benefit–risk assessment.
A July 2025 MHRA safety notice warned of a small increase in Guillain–Barré syndrome after the RSV vaccines Abrysvo and Arexvy in older adults. The Commission on Human Medicines nevertheless concluded that protection against RSV outweighed that risk. The notice did not describe a suspension of vaccination. MHRA source
Guillain–Barré syndrome is a serious condition affecting the nerves. The regulator asked clinicians to recognise possible symptoms promptly and explained that urgent hospital assessment can be necessary. It reported no evidence at that time of an increased risk after Abrysvo in pregnant people; that separate population should not be assigned the older-adult findings. MHRA source
Later UKHSA guidance, updated 11 August 2026, continues to describe a small increased risk in the six weeks after vaccination in older adults. It also notes that some cases following vaccination happen by chance and that infections themselves commonly precede the condition. Protection against severe RSV remains important in the eligible population. UK Health Security Agency source
Safety estimates from different studies, ages and observation periods are not interchangeable. This report does not turn suspected adverse-event notifications into a causal rate or repeat the older notice’s programme eligibility as current policy. The updated official guidance provides the appropriate programme context. UK Health Security Agency source
Known facts
- MHRA safety notice: 7 July 2025.
- Later UKHSA guidance retains favourable benefit–risk context.