Beyfortus
Beyfortus, a vaccine against Respiratory Syncytial Virus (RSV), a virus that is more likely to cause severe illness than other cough and cold viruses, was approved in November in Singapore and will be available in 2025. Should you get it for your newborn?
Beyfortus is an antibody given to infants as a single dose (some high-risk children get another dose at about age 1 year). It was approved in Europe in November 2022 and in the United States in July 2023.
Risks of RSV
What are the risks of RSV? The chance of being hospitalized for a child is about 1-2%, and 99% of hospitalized children will be fine. Oxygen is the main treatment. It can be severe, with about 1 in 5 hospitalized children needing intensive care and about 1 in 20 needing mechanical ventilation (a breathing tube).
The highest risk is for children under 2 months, and it is very rare for a child over 5 years to need to be hospitalized for RSV. Most children who need to be hospitalized are less than 18 months old, and probably 75% are under 6 months old.
Effectiveness of Beyfortus
Beyfortus is effective – it reduces the risk of hospitalization by more than 80%. This is good, but it’s a bit deceiving. The percentage seems impressive, but it really means that a child who gets RSV who had a 1 in 100 chance of being hospitalized now has a 1 in 300 chance, so you went from really unlikely to really really unlikely. In the best study published in 2023, 1% of children who got Beyfortus needed to be hospitalized for RSV by age 2 years! But if you didn’t get the vaccine, only 3% of children needed to be hospitalized. That same study showed the only significant benefit was to children under 2 months. Will it prevent your child from dying? No one knows yet, because the risk is so low it will take years to have enough infants getting the vaccine to know.
It does not prevent bronchiolitis from other viruses – RSV has been long known to be more severe, but a common cold virus can cause bronchiolitis. It varies year to year and region to region, but about a third of bronchiolitis admissions are due to viruses other than RSV.
Beyfortus is an antibody, not a true vaccine, so it wears off. It is 0% effective after 10 months, so a dose to an infant will not prevent RSV after age 1 year or so.
And yes, it will likely be expensive. In the United States, the listed price is more than 600 Singapore dollars for a dose. No one knows yet what the price will be in Singapore.
One other important RSV vaccine related issue – Abryvso. Abrysvo was approved in September 2024 for pregnant women, and recommended when you are at 32-36 weeks. It is 80% effective in preventing RSV hospitalization for an infant – the highest risk period for severe RSV.
Is Beyfortus recommended?
So, would I recommend Beyfortus for a newborn? It is safe and effective, so if cost is not an issue, yes. The benefit is very small overall, but it works. Overall, I would recommend Abryvso for everyone, and Beyfortus – if you can afford it – as well.
About Author
This article is written by Dr Leo Hamilton, who is a US board-certified Paediatrician since 2003. Dr Leo relocated to Singapore in 2011, caring for expat and Singaporean children from newborns at delivery to teenagers. Beyond his background in Hematology/Oncology, he has an interest in asthma, behavioural issues (primarily ADHD), teen health, and modern management of routine childhood illnesses such as ear infections, bronchiolitis, and pneumonia.
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