About influenza

Seasonal influenza typically begins suddenly and causes fever, dry cough, fatigue, and muscle aches lasting 3–10 days. Influenza can also lead to serious pneumonia and worsen chronic illnesses.

Each year, between December and April, the population in the northern hemisphere is affected by influenza epidemics. Two types of influenza virus, type A and B, cause these epidemics. Influenza viruses constantly evolve into new variants. This means that immunity from previous variants does not provide sufficient protection against illness caused by the new ones.

More information about influenza.

Who should get the influenza vaccine?

Risk groups included in the vaccination programme:

The following individuals have an increased risk of severe illness and death from influenza, and are therefore recommended to receive the influenza vaccine:

  • residents of nursing homes and care homes
  • everyone aged 65 years or over
  • pregnant women after the 12th week of pregnancy (2nd and 3rd trimester). Pregnant women in the 1st trimester with additional risk factors should also be offered the influenza vaccine
  • prematurely born children, especially those born before week 32 of pregnancy, from 6 months (chronological age) to 5 years
  • children and adults with:
    • chronic lung disease with reduced lung function, and asthma
    • chronic cardiovascular disease, excluding well-regulated high blood pressure
    • diabetes
    • chronic severe liver disease
    • chronic severe kidney disease
    • chronic severe neurological disease, especially individuals with reduced functional level, lung capacity and/or coughing ability, for example in cases of multiple sclerosis, cerebral palsy, Parkinson’s disease or ALS
    • weakened immune system due to illness and/or immunosuppressive treatment, for example following organ transplantation, cancer, autoimmune diseases
    • obesity with a body mass index (BMI) of 35 kg/m² or higher
    • other serious and/or chronic illness where influenza poses a significant health risk, following individual assessment by a doctor, such as individuals with congenital chromosomal abnormalities (for example Down’s syndrome) and genetic syndromes

Groups outside the vaccination programme who are recommended the vaccine

In addition, the influenza vaccine is recommended for the following groups, primarily to protect others (indirect protection):

  • healthcare personnel and other employees in the health and care services who have close contact with patients during treatment or care
  • individuals who live with (or are similarly close to) immunosuppressed persons
  • swine farmers and others who have regular contact with live swine
  • culling personnel and others who work with suspected or confirmed influenza-infected poultry

Why should you get the influneza vaccine?

Most children and adults cope well with flu, but many can become seriously ill. Influenza can lead to complications such as pneumonia, stroke, and worsening of many chronic conditions. Each year, more than 5,000 hospital admissions are caused by serious influenza-related complications. On average, around 900 people die from influenza every year.

Older adults and people with chronic conditions

Older adults and people with chronic illnesses or conditions are at greater risk of becoming seriously ill from influenza. Some may also experience lasting health problems following a severe case of influenza. Influenza can lead to serious complications such as pneumonia and worsening of many chronic conditions. For some, hospital admission becomes necessary.

People with cardiovascular disease are at increased risk of heart attack, stroke, and death during the influenza season compared to the rest of the year.

Pregnant women

Pregnant women are at higher risk of becoming seriously ill from influenza than others. The risk increases as the pregnancy progresses, and is also higher for those with some chronic conditions.

Influenza can lead to serious complications such as pneumonia. If you become seriously ill, this can also pose a risk to your baby. Influenza is associated with a slightly increased risk of stillbirth, and for newborns, the illness can be severe.

The influenza vaccine protects you during pregnancy and your baby in the first weeks after birth. Pregnant women can be vaccinated at any stage of pregnancy, but the vaccine is most beneficial in the second and third trimesters. If you have another chronic condition, you should be vaccinated in the first trimester. The recommendation for pregnant women applies to the influenza season (autumn and winter).

Children

Around 10 percent of children in Norway should receive the influenza vaccine because they have a condition that increases their risk of serious illness from influenza. Influenza can lead to serious complications such as pneumonia and worsening of underlying health conditions.

Each year, around 500 children are admitted to hospital with influenza. Children in risk groups are admitted with severe influenza four times more often than healthy children.

Where can I get the influenza vaccine?

Your local authority is responsible for offering the influenza vaccine to people in risk groups for severe illness. You can find information about where to get vaccinated on your municipality´s website.

Your GP can also offer the vaccine or provide information about where to get it. It is also possible to get the influenza vaccine at a pharmacy, and some people are offered it at their workplace.

The influenza vaccine is available from the beginning of October.

Do you have a GP through Helsenorge?

If your GP offers appointment booking through Helsenorge, you can log in here to book an appointment for vaccination.

What should I know before getting vaccinated?

The vaccine is given either as an injection or a nasal spray. Adults receive one dose as an injection in the arm. Children aged 2 to 17 may be offered either the nasal spray or an injection. Children under 9 who have not previously received the influenza vaccine will need two doses. From age 9, only one dose is needed.

You can receive other vaccines at the same time, such as the COVID-19 vaccine or the pneumococcal vaccine.

It takes 10 to 14 days after vaccination for the vaccine to take effect. For the best protection, you should get vaccinated between October and December. If you haven’t done so, it is still beneficial to get vaccinated throughout the winter season.

You should get vaccinated even if you have recently had influenza. If you are unwell with a fever over 38°C, you should wait until you are fever-free before getting the vaccine.

How often should I get the influenza vaccine?

If you are recommended to have the influenza vaccine, you should get it every year. This applies regardless of whether you have had influenza or been vaccinated in previous years. The influenza virus changes constantly, and the vaccine is updated due to the changes each season. The effect of the vaccine also decreases over time, so an updated vaccine provides the best protection.

Check your vaccination status

If you have children under the age of 16, you can also see which vaccines they have received.

How much does the influenza vaccine cost?

The cost depends on whether you are covered by the adult immunisation programme, your occupation, and which municipality you are living in. 

For people in risk groups, the vaccine costs 101 NOK per dose in the 2025/26 season. This is the same price for all vaccines in the immunisation programme. In addition to the vaccine cost, there is a fee for administering the vaccine. Many municipalites follow the recommended fee from the Directorate of Health, which this season is 200 NOK. This means a total of 301 NOK for the vaccine and administration. The price is the same even if you receive other vaccines at the same time through the adult immunisation programme. Speak to your GP or check your local municipality´s website for more information about pricing.

For household contacts of immunosuppressed individuals, the vaccine costs 101 NOK per dose through the municipality´s offer. The municipality sets the fee for administering the vaccine.

For most people not covered by the adult immunisation programme, the vaccine itself costs around 200 NOK. In addition, the vaccination provider charges a fee for administration, which varies by location.

Occupational groups recommended to receive the vaccine should have the cost covered by their employer.

If you are entitled to the vaccine through the immunisation programme, are a household contact of someone who is immunosuppressed, or are covered by your employer, it is important to receive the vaccine through the local municipality´s offer. Otherwise, you may have to pay more.

Effectiveness of the influenza vaccine

The effectiveness of the influenza vaccine varies from year to year and is on average around 60 percent. This means that about 6 out of 10 vaccinated people are protected from influenza. This also applies to pregnant women.

Effectiveness depends on the virus strains, the vaccine, and the person receiving it. For example, people with weakened immune systems and older adults may have a lower effect. Some people may still get influenza despite being vaccinated, but the vaccine reduces the risk of severe illness.

The influenza vaccine does not protect against other viruses or bacteria that can cause flu-like symptoms, such as coronavirus.

Side effects of the influenza vaccine

The injectable influenza vaccines may cause soreness, redness, and swelling at the injection site, as well as fever, mild illness, and muscle aches. Allergic reactions or other serious side effects are rare. These vaccines contain only parts of inactivated influenza virus and cannot cause influenza.

The nasal spray vaccine may cause a blocked or runny nose, and in some cases headache, mild illness, fever, or muscle aches. This vaccine contains weakened viruses that cannot spread in the body and therefore cannot cause influenza.

Symptoms after vaccination are not always caused by the vaccine and may be signs of another illness that requires treatment. Contact your doctor if you are concerned.

Which vaccines have you previously taken?

Content provided by Norwegian Institute of Public Health

Norwegian Institute of Public Health. Influenza vaccine (flu shot). [Internet]. Oslo: The Norwegian Directorate of Health; updated Monday, September 29, 2025 [retrieved Sunday, October 5, 2025]. Available from: https://www.helsenorge.no/en/vaccination/influenza-vaccine/

Last updated Monday, September 29, 2025