RSV in Babies: Prevention, Nirsevimab and the RSV Vaccine in SG

Respiratory syncytial virus (RSV) is a common virus that gives most adults a cold, but in young babies it can cause bronchiolitis and pneumonia, and it is a leading reason infants are admitted to hospital. Singapore parents now have two ways to protect babies from severe RSV: a long-acting antibody injection for the baby (nirsevimab, sold as Beyfortus) and an RSV vaccine given to mum in late pregnancy (Abrysvo).

Both are approved for use here, but as at October 2026 neither is part of the national childhood or adult immunisation schedules, so they are generally self-paid. This guide explains how each option works, who it is for, and what to ask your paediatrician or gynae.

What is RSV and why does it matter for babies?

RSV spreads through coughs, sneezes and touching contaminated hands, toys and surfaces. Almost every child catches it at least once by age two. In older children and adults it usually feels like a cold, but in babies the virus can inflame the tiny airways in the lungs, causing bronchiolitis.

The babies most likely to become seriously unwell are:

• Babies under 6 months, especially in their first few weeks
• Babies born prematurely
• Babies with heart or lung conditions, or a weakened immune system

Many babies who need hospital care for RSV were born healthy and at full term, which is why prevention is now offered more widely rather than only to high-risk infants. In Singapore’s tropical climate, RSV circulates all year round rather than in a neat winter season, with periods of higher activity.

Your two prevention options at a glance

Most babies need one or the other, not both. Your doctors can help you decide which suits your family and timing.

Nirsevimab (Beyfortus): the RSV antibody for babies

Nirsevimab is not a vaccine in the traditional sense. It is a monoclonal antibody: a lab-made version of the antibodies the immune system produces to fight RSV. Because the antibodies are given ready-made, protection starts quickly rather than relying on your baby’s immune system to respond.

Singapore’s Health Sciences Authority (HSA) approved Beyfortus in 2025. According to its approved product information, it is used to prevent RSV lower respiratory tract disease in:

• Newborns and infants during their first RSV season
• Children up to 24 months old who remain vulnerable to severe RSV through their second season, such as some babies with chronic lung or heart conditions

It is given as a single injection into the thigh, with the dose based on your baby’s weight. It is a prescription-only medicine, so your paediatrician will advise whether and when your baby should have it. It can usually be given around the same time as routine vaccines, but check with your doctor how they schedule it alongside your baby’s NCIS jabs.

Side effects

In clinical trials, side effects were uncommon and mostly mild, such as a rash, fever or redness and swelling where the injection was given. As with any medicine, serious allergic reactions are possible but rare, which is why babies are watched briefly after the injection.

Abrysvo: the RSV vaccine in pregnancy

The maternal RSV vaccine Abrysvo is given once, between 32 and 36 weeks of pregnancy. Your body makes antibodies, which cross the placenta, so your baby is born with protection that lasts through roughly the first six months.

It takes about two weeks after the vaccine for enough antibodies to pass to your baby. If your baby is born within two weeks of your vaccination, or you did not have the vaccine, doctors in many countries recommend the infant antibody instead. Your paediatrician will look at your vaccination date when deciding.

The vaccine is given within the 32 to 36 week window partly because studies of RSV vaccines in pregnancy looked closely at a possible link with preterm birth. Giving it later in pregnancy is part of keeping it as safe as possible. Common side effects for mum include a sore arm, headache and muscle aches.

For other vaccines in pregnancy, such as whooping cough (Tdap, recommended between 16 and 32 weeks in Singapore) and flu, see our guide to vaccines during pregnancy.

Availability and cost in Singapore

As at October 2026, neither RSV product appears on the National Childhood Immunisation Schedule (NCIS) or the National Adult Immunisation Schedule (NAIS) published by the CDA. That has a few practical effects:

• Subsidies: the NCIS and NAIS subsidies at polyclinics and CHAS GPs do not apply.
• Where to get it: availability depends on the hospital or clinic. Private paediatric clinics and gynae practices are the most likely to offer them, and some hospitals may offer the infant antibody after birth.
• Price: charges vary between providers and we have not been able to confirm a typical figure, so ask for a quote including consultation fees.
• MediSave and insurance: ask your clinic whether MediSave can be used and check your insurance policy, as coverage is not guaranteed for treatments outside the national schedules.

National recommendations can change, so check the latest CDA schedules or ask your doctor. A good time to raise it is at your third-trimester gynae visit and at your baby’s first paediatric appointment.

Everyday ways to lower your baby’s RSV risk

Immunisation is the most effective protection, but simple habits help too, especially in the first few months:

• Wash your hands before handling your baby, and ask visitors to do the same
• Keep anyone with a cold, cough or fever away from your newborn, including older siblings where possible
• Avoid crowded indoor places with very young babies when you can
• Clean toys and surfaces that older children touch often
• Keep your home and car smoke-free
• Breastfeed if you can, as breast milk offers some protection against infections

When to see a doctor

RSV usually starts like a cold, with a runny nose and cough. In babies, it can then move to the chest over a few days. Our baby cough and cold guide covers home care for mild symptoms.

The bottom line

• RSV is common and usually mild, but it can make young babies, especially those under 6 months or born early, seriously ill.
• Two options are available in Singapore: the infant antibody nirsevimab (Beyfortus) and the maternal vaccine Abrysvo, given at 32 to 36 weeks.
• Most babies need one or the other, not both.
• As at October 2026 neither is on the national schedules, so they are generally self-paid. Ask your gynae and paediatrician about availability and cost.

For official information, see the Communicable Diseases Agency’s RSV page.