Influenza is a respiratory illness which is highly contagious. It is a serious condition because the infection, at times, can lead to complications and even death.

Influenza, commonly known as the “flu”, is a contagious disease that can affect anyone including healthy people. It attacks the respiratory tract in humans (nose, throat, and lungs), causing inflammation of the mucous membranes.

It can be spread when an infected person coughs, sneezes, or speaks, as the flu viruses are transmitted into the air through droplets and other people breathe in the viruses. When these viruses enter the nose, throat, or lungs of a person, they begin to multiply, and subsequently cause flu symptoms.

The influenza virus can also be spread indirectly through surfaces that an infected person comes in contact with, such as doors, utensils, lift buttons, etc. When an uninfected person touches these surfaces and then touches his or her nose or mouth, they can get infected as well.

Transmission can also occur when an infected person shares food with others during mealtime without a serving spoon.

Flu symptoms usually come suddenly, and they typically include:

  • Fever
  • Sore throat
  • Coughing
  • Stuffy nose
  • Headache
  • Muscle aches

Other symptoms may include sneezing, nasal discharge, loss of appetite, fatigue, weakness, chills, and stomach symptoms.

Groups of people with compromised immunity, such as older people, young children, those with pre-existing conditions or diseases are more likely to develop serious complications if they get the flu.

  • Persons aged 65 years and older;
  • Children aged 6 months to 5 years;
  • Adults and children who have chronic disorders of the lungs (including asthma) or heart;
  • Adults and children who suffer from chronic metabolic diseases (including diabetes); people with kidney malfunction like those on dialysis; those with a blood disorder like thalassemia;
  • People whose immune resistance is lowered due to medications or those whose immune system is weakened due to the Human Immunodeficiency Virus (HIV) infection;
  • Children and teenagers aged 6 months to 18 years who are receiving long-term aspirin therapy (they are at risk of Reye syndrome, which is a deadly disease that affects all body organs especially the liver and brain, after influenza infection);
  • Women who are in the second or third trimester of pregnancy.

If you are part of a group that is at risk of developing influenza-related complications, or regularly exposed to those at risk of influenza-related complications, a flu vaccination would be the best protection for you against the flu.

Practising healthy habits and good personal hygiene is also important in protecting yourself and those around you from getting the flu, especially if you or those around you are not vaccinated.

  • Wash your hands thoroughly and regularly with soap and water, especially before touching your eyes, nose or mouth and after going to the toilet.
  • Cover your mouth and nose with a tissue when coughing or sneezing
  • Wear a surgical mask if you are unwell
  • See a doctor if you are feeling unwell
  • Do not go to school or work when you are ill
  • Never spit in public places
  • Use a serving spoon when sharing food at meal times

Influenza vaccination, or flu vaccination for short, is most beneficial for those who have high chance of developing complications (see list above) from an influenza infection. Unless advised otherwise by your doctor, it is recommended that you go for flu vaccination even if you are healthy, especially if you live with or take care of the following people:

  • The elderly (aged 65 years and above)
  • People with low immunity (e.g. under cancer treatment or have certain diseases like HIV)
  • Children aged 5 years and below

It is also advisable to get flu vaccination if you are a healthcare worker as you may regularly be exposed to different flu viruses. You will also be protecting your patients by preventing the spread of the virus to them.

The flu vaccination takes about 2 weeks to take effect, thus it’s better to get vaccinated early before flu season starts. In Singapore, the flu season generally occurs between December and February. Another peak season is from May to July.

Flu vaccines are offered in many locations, including hospitals, polyclinics, GP clinics such as all Healthway Medical clinics, and even schools.

A yearly vaccination is recommended as flu viruses are constantly changing, and your body’s immunity to influenza viruses may decline over time. Thus, getting vaccinated every year provides the best protection against influenza.


*Note: This flu vaccine does not give protection against bird flu or the H7N9. Currently, there is no vaccine for this strain.

Flu vaccination is generally safe and the majority of people who receive the vaccine experience little to no side effects. Side effects, even if they do occur, are generally minor and transient.
Possible side effects that can occur include:
  • Mild flu-like symptoms such as bodyaches, runny nose or cough
  • Low grade fever
  • Injection site mild redness, pain or swelling
  • Allergy (very rare)