Influenza Vaccine Information (Flu)

Influenza (The Flu) is a contagious disease

The flu is caused by the Influenza virus, which spreads from infected persons to the nose or throat of others. Other illnesses can have the same symptoms and are often mistaken for Influenza. Only an illness caused by the Influenza virus is really Influenza. Anyone can get the flu, but rates of infection are highest among children. For most people, the flu lasts only a few days.  The CDC recommends that  all persons aged ≥6 months receive a yearly flu vaccination.

The flu virus can cause:

  • fever
  • sore throat
  • chills
  • fatigue
  • cough
  • headache
  • muscle ache

Influenza can lead to Pneumonia and can be dangerous for people with heart or breathing conditions. It can cause high fever and seizures in children. On average, 226,000 people are hospitalized every year because of influenza and 36,000, mostly the elderly, die because of the flu.

Influenza vaccine (the flu shot) can prevent influenza.

For most people Influenza vaccine prevents serious Influenza related illness. But it will not prevent “Influenza-like” illnesses caused by other viruses. Influenza viruses are always changing. Because of this viral shift, Influenza vaccines are updated every year, and an annual vaccination is recommended. Protection lasts up to a year. It takes up to 2 weeks for protection to develop after the vaccination. Some inactivated Influenza vaccine contains thimerosal, a preservative that contains mercury. Some people have claimed that thimerosal may be related to developmental problems in children. In 2004 the Institute of Medicine published a report concluding that, based on scientific studies, there is no evidence of such a relationship. There are, however, some thimerosal free and preservative free types of the flu vaccine available from Passport Health.

There are two types of Influenza vaccine:

  • Inactivated (killed) vaccine, or the “flu shot”, is given by injection and can be given to people 6 months of age and older.
  • Live, attenuated (weakened) influenza vaccine, called LAIV, is sprayed into the nostrils (intra-nasal) and is approved for healthy people from 2 through 49 years of age, who are not pregnant. LAIV is thimerosal and preservative free.

Please read both Vaccine Information Statements (VIS) below and then ask your Passport Health Travel Medical Specialist which vaccine is right for you.

In general, the Influenza vaccine is recommended for:

  • Anyone who is at risk of complications from Influenza or more likely to require medical care
  • Anyone who lives with or cares for people at high risk for Influenza related complications
  • People who provide essential community services.
  • People living in dormitories or under other crowded conditions, to prevent outbreaks
  • People at high risk of Influenza complications who travel to the Southern hemisphere between April and September or to the tropics or in organized tourist groups at any time
  • Anyone who wants to reduce the likelihood of becoming ill with Influenza or spreading Influenza to others.

Plan to get the Influenza vaccine in October or November if you can. Getting vaccinated in December, or even later, will still be beneficial in most years. You can get the vaccine as soon as it is available, and for as long as illness is occurring. In the northern hemisphere, Influenza illness can occur any time from November through May. Most cases usually occur in January or February. Most people need one dose of Influenza vaccine each year. Children younger than 9 years of age getting Influenza vaccine for the first time should get 2 doses. For inactivated vaccine, these doses should be given at least 4 weeks apart. Influenza vaccine may be given at the same time as other vaccines, including Pneumococcal vaccine.

Remember that Influenza occurs throughout the year worldwide because of the difference in seasons.

Sources: CDC Vaccine Information Statements (VIS): Inactivated Influenza and
Live, Attenuated Influenza

So, if you are asking yourself, “What travel shots and vaccinations do I need?” or “Where do I get a flu shot (influenza vaccine)?” call 888-499-PASS (7277) or find the Passport Health travel medicine clinic nearest you.

You can also learn more about diseases and vaccines that may impact your trip.