A new vaccine offered to millions of pensioners and pregnant women could trigger a serious neurological condition, officials have warned.
The alert, issued by US health chiefs, concerns a jab that protects against respiratory syncytial virus (or RSV), which was rolled out to vulnerable people in Britain for the first time last year.
The Food and Drug Administration (FDA) said results of an American study suggested two types of RSV jab carry a significant increased risk of Guillain-Barré syndrome — a disabling condition that causes damage to nerves — 42 days after vaccination.
While still recommending the jabs for eligible adults, the FDA officials said Guillain-Barré syndrome would now be listed as a risk in leaflets given to patients.
In the UK, the condition is already noted as a potential complication in patient information, however not all of those who receive the jab will be warned verbally of the risks.
Respiratory syncytial virus (RSV) is a bug that causes coughs and colds in most people, but can be potentially deadly for the elderly as well as young babies.
RSV, which is spread by coughs and sneezes, hospitalises about 30,000 children and 18,000 adults in the UK every year, due to serious breathing complications like pneumonia.
Around 100 children die from the virus each winter. It’s also estimated to contribute to the deaths of 8,000 adults over the same period due to the increased strain the infection puts on patient’s hearts, causing the organ to fail.
US health chiefs issued a warning about RSV jabs, which was only launched in Britain last year, in an alert earlier this month. Stock image
In the US Food and Drug Administration (FDA) study, officials combed through vaccine reaction data on two RSV jabs, called Abrysvo and Arexvy, documented between May 2023 and July last year.
They found that for Abrysvo, the type of RSV jab offered in the UK, there were an additional nine cases of Guillain-Barré syndrome per every million doses of the vaccine dished out.
For Arexvy, there was an additional seven cases of the syndrome per million doses.
This is significantly more than the equivalent for the flu vaccine, which generates one to two cases of Guillain-Barré syndrome per million vaccine doses.
However, the FDA added that the new study didn’t change the current advice — the benefits of RSV vaccination outweighs the risks for vulnerable groups.
Guillain-Barré syndrome is a poorly understood condition.
It occurs when the body’s immune system, which normally protects people from infection, mistakenly attacks healthy nerve cells.
Initial signs include a tingling and numbness in the hands and feet, which is followed by muscle weakness and difficulties moving in the following weeks.
In some cases, it can lead to problems breathing, facial paralysis and impaired vision.
For young children and older adults, RSV can lead to breathing difficulties and even severe pneumonia-like lung infections
Guillain-Barré syndrome is normally temporary if treated.
While most patients recover within a year, some are left with permanent nerve damage.
What triggers the immune system to attack nerve cells in Guillain-Barré syndrome isn’t understood.
But, as the syndrome can also occur following an infection with a virus or bacteria, some experts suspect it’s caused by a misfiring of the immune system in response to a foreign substance, be that a pathogen or a vaccine.
Such reactions, from both infections or RSV vaccines, are rare, with the risk estimated to be about one in every 1,000.
In Britain, the RSV vaccine Abrysvo, made by Covid jab manufacturer Pfizer, is offered to adults aged 75 to 79 to help protect them against serious respiratory infections.
Pregnant women past 28 weeks are also advised to get the jab as it passes on protective anti-RSV antibodies to newborn children.
The latest data shows that as of December, nearly half of eligible older adults in England took up the offer of an RSV vaccine.
Data on uptake among pregnant women lags behind. The latest uptake figures are for September last year and show only a third of eligible woman had taken up the offer.
RSV is usually spread via coughs and sneezes, close contact with an infected person or contact with contaminated surfaces
More recent NHS data shows that, as of last week, 1.5million eligible adults in England had been given the RSV vaccine, of which 140,000 were pregnant women.
Dr Conall Watson consultant epidemiologist for the UK Health Security Agency, said: ‘The RSV vaccine offers a vital opportunity for any mums-to-be to protect their babies from severe RSV lung infection.’
‘It’s encouraging to see the RSV programme getting off to such a positive start with over a third of women who gave birth in September having had the vaccine.’
NHS officials warn that RSV cases are high this year, with hospital data showsing an average of 28 children are hospitalised with the virus everyday — a rate that’s 41 per cent higher than last year.
As the RSV jab was launched in September last year women who’ve lost newborn babies to RSV pleaded with expectant mothers to have the vaccine.
The latest NHS data, for the 2023-2024 financial year, recorded about 3,000 admissions for Guillain-Barré syndrome in England’s hospitals though some cases could be the same patient needing to admitted multiple times that year.
Guillain-Barré syndrome is more common among adults and men for reasons scientists are still investigating.
