RSV Vaccine

What is RSV infection?

Respiratory syncytial virus (RSV) is a highly contagious respiratory virus that infects the nose, throat, airways, and lungs. In most healthy adults, RSV causes mild, cold-like symptoms. However, in vulnerable groups such as infants, older adults, and those with weakened immunity, RSV can cause severe illness requiring hospital care.

The virus spreads through respiratory droplets when an infected person coughs or sneezes, by direct contact, or via contaminated surfaces. Once inside the body, RSV targets the cells lining the respiratory tract, beginning in the upper airways and sometimes progressing into the lower airways and lungs.

What are the types of RSV?

The infection is classified into 2 main subtypes, which are:

• RSV Type A – often linked to larger and more severe outbreaks, particularly in high-risk populations
• RSV Type – generally causes milder symptoms but can still lead to severe disease in vulnerable individuals

Both subtypes circulate simultaneously during RSV season and can cause reinfection because the virus changes slightly over time. This means a previous infection with one subtype does not guarantee immunity to the other. Vaccination is designed to provide targeted protection against both.

What are the complications of RSV infection?

While many RSV infections are resolved without complications, certain groups face a higher risk of developing serious lower respiratory tract disease. These conditions can require hospitalisation and sometimes lead to long-term respiratory problems.

Some of the complications are:

• Asthma flare-ups – RSV can trigger airway inflammation and narrowing in people with asthma, causing wheezing and chest tightness
• Bronchiolitis – swelling and mucus build-up in the small airways of the lungs, common in infants and toddlers, leading to wheezing and rapid breathing
• Pneumonia – infection of the lung tissue, causing fluid-filled air sacs that limit oxygen intake
• Tracheobronchitis – inflammation of the windpipe and bronchi, resulting in a deep and harsh cough and breathing discomfort

What is the RSV Vaccine?

The RSV vaccine is designed to protect against serious illness caused by the respiratory syncytial virus. It works by exposing the immune system to a harmless part of the virus, enabling the body to recognise and fight RSV if exposed in the future.

Vaccination reduces the likelihood of severe lower respiratory tract infections, helps prevent hospitalisation, and plays a key role in protecting vulnerable groups during RSV season. In pregnant women, the vaccine can also help protect newborns through the transfer of antibodies before birth.

How does the RSV Vaccine work?

Rather than exposing the body to the whole virus, RSV vaccines contain purified proteins, most often the fusion (F) protein, that are crucial for RSV to infect cells.

Once introduced into the body:

• The immune system identifies the protein as foreign and produces antibodies to neutralise it
• Immune memory cells are formed, enabling a faster and stronger defence if RSV is encountered again
• This response helps block the virus from reaching the lungs and causing severe lower respiratory tract disease

What are the types of RSV Vaccines available?

Singapore currently offers 2 approved RSV vaccines, both based on the F protein but formulated differently for specific patient groups:

• Arexvy — uses the F protein combined with an adjuvant (AS01) to enhance the immune response. This vaccine is recommended for:
  • Adults aged 60 and above
  • Adults aged 50 to 59 years old are at elevated risk of RSV-related lower respiratory tract disease

• Abrysvo— contains the F protein without adjuvant and is suitable for maternal immunisation. It is best for:
  • Pregnant women at 32 to 36 weeks of gestation
  • Adults aged 60 years and above
  • Adults aged 18 to 59 years old who are at elevated risk of RSV-related lower respiratory tract disease

What are the benefits of RSV Vaccination?

RSV vaccination is more than just a safeguard against infection. It is an important step in reducing the health, emotional, and economic burden that RSV can place on individuals, families, and healthcare systems.

Receiving the RSV vaccine provides multiple layers of protection, such as:

• Milder illness if infected – reduces the intensity of symptoms,  helping you recover faster and with fewer complications
• Lower risk of hospitalisation – critical for elderly patients, newborns, and those with chronic health conditions
• Prevent RSV infections – the vaccine can prevent more than 70% of RSV-related vaccines
• Protection for newborns via maternal antibodies – vaccination during pregnancy allows protective antibodies to pass to the baby, guarding against RSV in their first 6 months
• Seasonal coverage – strengthens your defences ahead of RSV’s peak circulation, when the risk of infection is highest
• Community-level protection – reduces the spread of RSV in environments where vulnerable individuals live or interact closely, such as care facilities and multi-generational households

Who should get the RSV Vaccine?

Not everyone needs an RSV vaccination, but it is strongly advised for those who face a higher chance of severe complications. This includes:

• Older adults – ageing can weaken the immune system, increasing the risk of pneumonia and related illnesses
• Pregnant (32 to 26 weeks) – immunisation during this window allows antibody transfer to the body, offering early-life protection
• People with chronic lung or heart disease – conditions such as chronic obstructive pulmonary disease (COPD), asthma, and heart failure can worsen significantly if RSV is contracted
• Individuals with compromised immunity – weakened immune responses due to illness or medication make RSV harder to fight off

Who should not get the RSV Vaccine?

While RSV vaccines are safe and effective for most eligible adults, there are certain situations where they may not be recommended. Our doctor will assess your circumstances to ensure vaccination is both safe and beneficial for you.

You may be advised to avoid RSV vaccination if you:

• Allergies – have had a severe allergic reaction to a previous dose of an RSV vaccine or any of its components
• Are acutely unwell — if you have a moderate or severe illness, vaccination may be postponed until you recover
• Have a history of Guillain–Barre syndrome — a rare neurological disorder that can sometimes occur after vaccination
• Are pregnant before 32 weeks of gestation — for maternal immunisation, timing is important to balance protection for the newborn and reduce the risk of pre-term birth

What can you expect from getting the RSV Vaccine?

Getting vaccinated is a quick and straightforward process, but knowing what happens at each stage can help you feel at ease and make the experience more comfortable.

This generally entails:

Before vaccination

Before prescribing any injections, our doctor will take a moment to ensure the vaccine is right for you. You will be assessed on:

• Your medical history, current health status, and any past reactions to vaccines will be thoroughly reviewed
• Pregnant women will have their gestational age confirmed to ensure timing falls within the recommended 32 to 36 week window for maternal immunisation
• If you are unwell with a moderate or severe illness, or have a fever, your appointment may be postponed until you recover

During vaccination

The appointment itself is quick, and the injection takes only a few seconds. Our doctor will guide you through the process and make sure you are as comfortable as possible. The procedure consists of:

• The RSV vaccine is given as a single intramuscular injection, usually into the upper arm
• Most people describe the sensation as a brief pinch or light pressure
• You may be asked to stay for 15 to 30 minutes after your shot so the clinic team can monitor you for any rare, immediate reactions

After vaccination

Once your injection is complete, you can carry on with your day as normal. After receiving the vaccination, you can expect:

• Soreness, redness, or swelling at the injection site
• Fatigue or low energy
• Headache
• Muscle aches or mild joint discomfort

These symptoms often settle within 1 to 2 days and can be eased with rest, hydration, and over-the-counter pain relief if advised by your doctor. However, do seek urgent medical care if you develop severe symptoms such as swelling of the face or throat, difficulty breathing, or a widespread rash, as these could be signs of anaphylaxis.

Summary

RSV may be a common virus, but for vulnerable individuals, including newborns, older adults, and people with weakened immune systems, it can lead to serious illness and hospitalisation. Vaccination offers a strong layer of protection, helping to reduce your risk of infection, limit the severity of symptoms, and safeguard the health of your loved ones and community.

By choosing to get vaccinated, you are not just protecting yourself. You are taking an active step towards preventing the spread of RSV to those who may not be able to fight it off as easily. Book your RSV vaccination today and give yourself the confidence of knowing you are protected when it matters most.

Frequently Asked Questions