ISSUE 3 JUNE
Reproduced with permission from Therapeutic Goods Administration (TGA) Medicines Safety Update 19 May 2025.
Summary
Arexvy and Abrysvo are newly registered vaccines against respiratory syncytial virus (RSV). This infection affects the respiratory tract and can cause severe disease, particularly in very young and older people.
Safety information for both vaccines has been updated to reflect the low risk of people contracting Guillain–Barré syndrome (GBS) following vaccination. This is a disorder in which the body’s immune system damages nerve cells, causing muscle weakness and sometimes paralysis. Most people recover completely from GBS, but some serious illnesses can be fatal.
- Arexvy and Abrysvo are both approved for individuals 60 years and older to prevent lower respiratory tract disease caused by RSV.
- Arexvy is also approved for individuals aged 50 to 59 who are at increased risk for RSV infection.
- Abrysvo is also approved for pregnant women between 24 and 36 weeks of gestation to prevent lower respiratory tract disease in infants from birth to 6 months of age as they acquire antibodies to RSV while in the womb. This is funded under the National Immunisation Program (for women between 28 and 36 weeks of gestation).
Given the potential severity of RSV infection and the rarity of GBS, the benefit–risk balance remains strongly in favour of vaccination in the target groups.
What health professionals should do
Health professionals should be aware of the higher GBS risk in people following vaccination with Arexvy or Abrysvo. Patients should be warned of this possible but rare risk and encouraged to seek medical attention if they experience symptoms, as early medical care can reduce severity and improve outcomes.
According to data from the US presented in October 2024, there were an estimated 9 excess cases of GBS per million doses of Abrysvo, and an estimated 7 excess cases per million doses of Arexvy administered to individuals aged 65 years and older. Direct comparisons of excess GBS case estimates between vaccine studies or populations is not possible due to background risk factors for GBS in the populations studied.
Health professionals should be alert to signs and symptoms of GBS to ensure correct diagnosis, in order to initiate adequate supportive care and treatment, and to rule out other causes.
Symptoms of GBS include pins and needles (paraesthesia), numbness, weakness and paralysis. Typically, hands and/or feet are affected first, with symptoms progressing up the body to the legs, arms, face and muscles involved with breathing. These symptoms may progress over a few days or weeks.
See the full article on the TGA website.
