When To Get Your Flu Shot Before Traveling

Flu is a common infection caused by the influenza virus, which is mainly spread when an infected person coughs or sneezes. The risk of catching the flu depends on when and where you're travelling, how long you're travelling for, and your type of travel. It is recommended that travellers get vaccinated at least two weeks before travelling to allow the body to develop immunity. In the Northern Hemisphere, the flu season can begin as early as October and last until April or May. In the Southern Hemisphere, flu activity typically occurs from April to September. In the tropics, flu activity occurs throughout the year.

Flu season in the Northern Hemisphere

In the Northern Hemisphere, the flu season can begin as early as October and last until April or May, with flu activity most commonly peaking between December/January and February/March. The flu vaccine used in the Northern Hemisphere typically protects against the main viruses that have been circulating in other parts of the world.

The flu vaccine is recommended for everyone aged 6 months and older, and it should be administered yearly, preferably before the flu season starts. It's important to get vaccinated at least 2 weeks before travelling, as it takes 2 weeks for immunity to develop. For those who are at a higher risk of flu-related complications, it's crucial to get vaccinated and discuss additional precautions with a healthcare provider.

If you are planning to travel, it's important to consider the flu season at your destination. The timing of the flu season varies between the Northern and Southern Hemispheres. In the temperate regions of the Southern Hemisphere, flu activity typically occurs from April to September. In the tropics, flu activity can occur throughout the year, although it is often more intense during the rainy seasons.

When travelling, it's essential to follow local guidelines and practice healthy habits. Wash your hands frequently with soap and water or use an alcohol-based sanitiser. Avoid close contact with sick people, and monitor your health for any flu-like symptoms. If you do experience flu-like symptoms, stay at home and avoid travelling until your fever has subsided without the use of fever-reducing medication.

Flu season in the Southern Hemisphere

The flu, or influenza, is a viral infection that attacks the nose, throat and lungs. It is a common illness in all parts of the world. In the Southern Hemisphere, the flu season typically occurs during April through September in temperate regions, and all year round in tropical regions.

In the Northern Hemisphere, the flu season can begin as early as October and last until April or May. However, in the Southern Hemisphere, the flu season occurs during the opposite months. This is because the Southern Hemisphere experiences opposite seasons to the Northern Hemisphere. So, while the Northern Hemisphere experiences winter from December to February, the Southern Hemisphere experiences summer.

The flu is a highly contagious respiratory infection that spreads easily between people when they cough or sneeze. It is caused by influenza viruses, with types A and B being responsible for seasonal epidemics. The flu usually lasts around a week, but can cause severe illness or even death, especially in high-risk groups.

To prevent the flu, vaccination is key. Vaccination can protect against the main flu viruses circulating in other parts of the world. It is recommended that travellers get a flu vaccine at least two weeks before their trip, as it takes two weeks for immunity to develop. This is especially important for those travelling to parts of the world where flu activity is ongoing, and for those at higher risk of flu-related complications.

Other preventative measures include practising good hygiene, such as washing hands frequently with soap and water, and avoiding close contact with sick people. It is also important to stay home and not travel if you are sick, and to seek medical care if you have severe illness or are at risk of flu complications.

Flu season in the tropics

In the tropics, flu activity occurs throughout the year, unlike the temperate regions of the Northern and Southern Hemispheres, which have more predictable flu seasons. This poses challenges for prevention and management, as public health officials are unable to prepare for flu season by timing vaccine campaigns or preparing healthcare settings for higher caseloads.

Influenza Seasonality in the Tropics

While flu season in the Northern Hemisphere typically lasts from October/November to April/May, and in the Southern Hemisphere, from April to September, the tropics experience flu activity all year round. This is likely due to the high humidity in the tropics, which facilitates influenza transmission.

A study on influenza seasonality in the tropics and subtropics found that most countries in Central and South America, as well as South and Southeast Asia, showed a single distinct peak of influenza activity, usually between April and June. However, countries near the equator, such as Indonesia, Malaysia, Singapore, and Vietnam, showed identifiable year-round activity.

In Africa, the influenza seasonality patterns are more complex and varied. Saharan Africa and the Middle East showed a single distinct peak, while countries like Mali, Burkina Faso, Ethiopia, and Rwanda had two distinct peaks. Similar to the countries near the equator in Asia, countries in Africa near the equator, such as Côte d'Ivoire, Ghana, Kenya, and Uganda, also showed identifiable year-round activity.

Vaccination Considerations for the Tropics

Due to the unpredictable nature of influenza in the tropics, it is recommended that travelers get vaccinated at least two weeks before their trip to maximize protection. The flu vaccine used in the Northern Hemisphere usually protects against the main flu viruses circulating in other parts of the world. However, it is still important to investigate the current flu activity in your specific region of travel, as flu outbreaks can occur at any time of the year, especially when traveling as part of large tourist groups or when exposed to strains circulating elsewhere.

It is also important to note that even if you receive the previous season's vaccine before traveling during the summer months, you should still receive the new flu vaccine when it becomes available in the autumn to protect against the expected flu viruses over the upcoming flu season.

Who is at high risk of flu-related complications

The flu vaccine takes two weeks to reach full effectiveness, so it is recommended that you get your flu shot at least two weeks before you travel.

People who are at high risk of developing serious flu-related complications include:

• Children younger than 5, especially those younger than 2 years old.
• Adults 65 years of age and older.
• Pregnant women (and women up to two weeks postpartum).
• Residents of nursing homes and other long-term care facilities.
• People with medical conditions such as:
• Neurological and neurodevelopmental conditions (disorders of the brain, spinal cord, peripheral nerve, and muscle).
• Chronic lung disease (e.g. Chronic Obstructive Pulmonary Disease (COPD) and cystic fibrosis).
• Heart disease (e.g. congenital heart disease, congestive heart failure, and coronary artery disease).
• Blood disorders (e.g. sickle cell disease).
• Endocrine disorders (e.g. diabetes).
• Metabolic disorders (e.g. inherited metabolic disorders and mitochondrial disorders).
• A weakened immune system due to disease or medication (e.g. people with HIV or AIDS, cancer patients, or those on chronic steroids).
• People younger than 19 years of age who are receiving long-term aspirin therapy.
• People with a body mass index (BMI) of 40 or more.

Flu symptoms

The flu is a contagious respiratory illness that can affect your nose, throat, and sometimes your lungs. It is caused by an influenza virus. The flu is different from a simple cold and can cause major outbreaks and severe disease.

• Fever or feeling feverish/having chills (although not everyone with the flu will have a fever)
• Shortness of breath or difficulty breathing
• Runny or stuffy nose
• Muscle pain or body aches
• Diarrhea (more common in children)
• Cough
• Sore throat
• Headache
• Fatigue
• Abdominal pain (more common in children)

If you are experiencing flu-like symptoms, it is important to stay home and avoid close contact with other people. You should also seek medical attention if your symptoms are severe.

To prevent the flu, it is recommended to get a flu vaccination every year, especially if you are travelling to parts of the world where flu activity is ongoing. It is advised to get the vaccine at least two weeks before travelling to allow your body to develop immunity.

Frequently asked questions