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Influenza, more commonly known as the flu, is a contagious respiratory illness caused by influenza viruses. In Singapore, the flu is fairly common, given the hot and humid weather all-year-round, creating a conducive environment for viruses to survive and circulate easily. 

Flu vaccinations remain the most effective way to prevent influenza and its complications. It not only reduces the likelihood of falling ill but also limits the severity of symptoms if infection occurs. Moreover, getting vaccinated helps reduce the spread of the virus in the community as it protects those who are unable to receive the vaccine, such as very young infants or individuals with specific medical conditions. In this article, we’ll look into flu vaccinations in Singapore, who needs them, and why. 

Understanding the Flu: Spread and Symptoms

Influenza is an acute viral infection caused by influenza viruses, which primarily affect the respiratory system. There are four main types of influenza viruses, A, B, C, and D, but only types A and B are responsible for seasonal flu outbreaks in humans [4]. These viruses are highly infectious and have the ability to mutate rapidly, resulting in new strains that can vary from year to year.

Influenza spreads mainly through droplets expelled when an infected person coughs, sneezes, or talks. These droplets can land in the mouths or noses of nearby individuals or be inhaled into the lungs. The virus can also spread through contact with contaminated surfaces, such as door handles or shared devices, followed by touching the face. Because it can be transmitted before symptoms appear and up to a week after falling ill, influenza is particularly difficult to contain without proactive measures like vaccination and good hygiene practices.

Potential complications of influenza include:

• Pneumonia — a serious lung infection that can be life-threatening, especially in the elderly and those with chronic illnesses.

• Sinus and ear infections — particularly in children.

• Exacerbation of chronic conditions — such as asthma, diabetes, and heart disease.

• Hospitalisation or death — in severe cases, particularly among vulnerable populations.

Why is the flu so common in Singapore?

The flu is relatively common in Singapore for the following reasons:

• Tropical climate — Because of Singapore’s constant warm and humid climate, influenza viruses can circulate all-year-round. 

• High population density — Singapore is a densely populated urban society, which increases chances of person-to-person transmission.

• International travel hub — The country is well-known for being an international travel hub, increasing risk of imported flu strains.

• Enclosed environments — Enclosed, air-conditioned spaces are common in Singapore, and are conducive spaces for virus survival and transmission.

Who Should Consider a Flu Vaccine?

Influenza vaccination is recommended for everyone aged 6 months and older, with rare exceptions. The Ministry of Health (MOH) in Singapore [5], along with global health authorities such as the World Health Organization (WHO) [6], advises annual flu vaccination as a key preventive measure. This is because influenza viruses evolve constantly, and the vaccine is updated regularly to offer protection against the most common circulating strains.

While the general population can benefit from vaccination, certain groups face a significantly higher risk of developing serious complications from the flu. For these individuals, the flu vaccine is not only a preventive measure, it can be life-saving.

Elderly Individuals (65 years and Above)

Older adults are more vulnerable to severe flu-related illnesses [7]. With age, the immune system weakens, which minimises the body’s ability to fight infections effectively. Influenza in the elderly is more likely to lead to hospitalisation, pneumonia, and, in some cases, death. Annual vaccination offers critical protection by reducing the severity of illness and the risk of complications.

Young Children (6 months to Under 5 Years)

Young children, particularly those under five years of age, have less developed immune systems, which makes them more susceptible to influenza and its complications, including febrile seizures and respiratory infections [8]. The flu vaccine helps to strengthen their immunity and reduce transmission in childcare settings and homes.

Pregnant Women

Pregnant women are more prone to severe flu symptoms and complications, especially in the later stages of pregnancy [9]. Importantly, the flu vaccine also provides protection to the unborn child, with antibodies passed from mother to baby. Vaccination is safe during any trimester and is strongly recommended as part of routine maternal care.

Individuals with Chronic Medical Conditions

People living with chronic conditions such as diabetes, asthma, chronic lung disease, heart disease, or compromised immune systems are more likely to experience complications from the flu [10]. Influenza can exacerbate existing conditions and lead to longer recovery times. Annual vaccination helps lower these risks and prevents disease flare-ups triggered by flu infection.

Healthcare Workers and Caregivers

Those who work in healthcare or provide care to vulnerable individuals, such as the elderly or chronically ill, are at increased risk of contracting and spreading influenza. Vaccinating this group not only protects them but also helps safeguard the health of the people they care for.

When’s the best time to get a flu vaccination?

There is no hard-and-fast rule when it comes to getting a flu vaccine. However, there are certain instances where it may be more beneficial for you, such as:

• Peaks in flu circulation — In Singapore, ideal times to get a flu vaccine would be in April, to protect against the mid-year spike, and October to protect you until the end of the year, when flu more commonly spreads. 

• Before traveling — Getting a flu vaccination right before a trip can help prevent you from falling ill and putting a halt on your holiday. 

• Before the school term starts — Schools are high-risk environments for flu transmission, and getting your child vaccinated ensures a good start to their school term, protecting them from infection.

• Before medical procedures — If you expect to be hospitalised or have a compromised immunity, getting a flu vaccination will be ideal for extra protection and optimal outcomes while you heal from your procedure. 

Addressing Common Misconceptions

Despite widespread public health campaigns and scientific evidence, several misconceptions about the flu vaccine persist. These misunderstandings can discourage people from getting vaccinated; as a result, they may put themselves and others at risk. Here are some common myths associated with influenza vaccines.

“The Flu Vaccine Can Cause The Flu”

This is one of the most persistent myths. In reality, the flu vaccine used in Singapore contains inactivated (killed) viruses or fragments of the virus that cannot cause illness. These components are designed to trigger an immune response, which helps the body build protection without causing infection.

Some people may experience mild side effects after vaccination, such as a low-grade fever, fatigue, or soreness at the injection site, but these are signs that the immune system is responding to the vaccine, not symptoms of influenza. The flu vaccine cannot give you the flu.

“Healthy Individuals Don’t Need the Vaccine”

It’s a common belief that flu vaccination is only necessary for the elderly or people with chronic illnesses. While high-risk groups are more likely to experience severe complications, healthy individuals can still get infected and suffer from uncomfortable symptoms, time off work or school, and, in rare cases, complications like pneumonia.

Moreover, healthy individuals can transmit the virus to others, including family members or colleagues who may be more vulnerable. Vaccinating healthy people contributes to community protection and helps break the chain of transmission.

“Vaccination Is Unnecessary If It’s Not Flu Season”

Unlike temperate countries with clear flu seasons, Singapore experiences influenza activity throughout the year, with peaks typically seen from May to July and November to January. This makes it important to stay protected regardless of the time of year.

Waiting for a “flu season” in Singapore can lead to missed opportunities for prevention. As immunity builds about two weeks after vaccination, timely vaccination, before known peak periods or ahead of travel to countries experiencing seasonal outbreaks, is essential for effective protection.

Potential Side Effects and Safety

The flu vaccine has a strong safety track record and is generally well-tolerated. Still, knowing what to expect can help you feel more confident about your decision.

Common Side Effects

Most people experience no issues after their flu shot. If side effects do occur, they are usually mild and go away within a couple of days. These may include:

• A sore or slightly swollen area around the injection site
• Low-grade fever
• Mild fatigue or muscle aches

These are normal immune responses and a sign that your body is developing protection.

Rare Side Effects

Severe reactions to the flu vaccine are extremely rare. In isolated cases, people may have allergic responses, such as hives, swelling, or breathing difficulties, usually within minutes of the injection.

Our clinical team monitors every patient briefly after vaccination and is fully equipped to manage any adverse reaction safely and promptly.

Why Flu Vaccination Matters Now More Than Ever

At Ardennes Health, we offer seasonal influenza vaccinations as part of our commitment to preventive care for individuals and families.

Influenza continues to be a significant public health concern in Singapore, as it affects people across all age groups. With year-round flu activity and seasonal surges, the importance of annual vaccination cannot be overstated. The flu vaccine offers reliable protection — not only reducing your risk of falling ill but also helping to prevent severe complications, hospitalisations, and the spread of the virus to others. 

If you are unsure about whether the flu vaccine is right for you, our medical team is here to provide clear, personalised guidance based on your health needs. Book an appointment (link to contact us page) with us today for a consultation. 

References 

1. Flu measures. (22nd April 2008.). Ministry of Health. Retrieved April 7, 2025, from https://www.moh.gov.sg/newsroom/flu-measures/ 
2. Drobnik, J., Pobrotyn, P., Witczak, I. T., Antczak, A., & Susło, R. (2021). Influenza as an important factor causing increased risk of patients’ deaths, excessive morbidity and prolonged hospital stays. Archives of Medical Science : AMS, 19(4), 941–951. https://doi.org/10.5114/aoms/138145 
3. Influenza vaccination services offered by community pharmacists under new sandbox initiative. (n.d.). Ministry of Health. Retrieved April 7, 2025, from https://www.moh.gov.sg/newsroom/influenza-vaccination-services-offered-by-community-pharmacists-under-new-sandbox-initiative/ 
4. CDC. (2024, September 27). Types of influenza viruses. Influenza (Flu). https://www.cdc.gov/flu/about/viruses-types.html 
5. Protocols and enhanced screening measures to prevent cross-border spread of influenza into singapore. (6th March 2025). Ministry of Health. Retrieved April 7, 2025, from https://www.moh.gov.sg/newsroom/protocols-and-enhanced-screening-measures-to-prevent-cross-border-spread-of-influenza-into-singapore/ 
6. Strengthening influenza vaccination policies and programmes. (n.d.). Retrieved April 7, 2025, from https://www.who.int/news/item/04-02-2025-strengthening-influenza-vaccination-policies-and-programmes 
7. Flu and older adults. (2022, June 14). National Institute on Aging. https://www.nia.nih.gov/health/flu/flu-and-older-adults 
8. CDC. (2024, September 26). Respiratory viruses and young children. Respiratory Illnesses. https://www.cdc.gov/respiratory-viruses/risk-factors/young-children.html 
9. Oseghale, O., Vlahos, R., O’Leary, J. J., Brooks, R. D., Brooks, D. A., Liong, S., & Selemidis, S. (2022). Influenza virus infection during pregnancy as a trigger of acute and chronic complications. Viruses, 14(12), 2729. https://doi.org/10.3390/v14122729 
10. American Lung Association. Flu symptoms and risk factors. Retrieved April 7, 2025, from https://www.lung.org/lung-health-diseases/lung-disease-lookup/influenza/symptoms-causes-and-risk 
11. Kim, T. H. (2014). Seasonal influenza and vaccine herd effect. Clinical and Experimental Vaccine Research, 3(2), 128–132. https://doi.org/10.7774/cevr.2014.3.2.128