Influenza Vaccine for Health Care Workers : FAQ's

How common is influenza?

Influenza is a very common infection. Epidemics of influenza occur most years during the "influenza season", usually from October to March. Worldwide about 10-15% of people get influenza every year. During major epidemics this can be as high as 50%. Attack rates of up to 50% may also be seen in closed communities, such as long-term care facilities.

How serious is influenza?

Most people with influenza are sick for a few days, and can feel very ill during this time with a high temperature, chills, sore throat, muscle pains and headache. Some people have a much more serious illness and may need to be admitted to hospital. Complications of influenza include pneumonia, worsening of chronic medical conditions (especially chronic heart and lung conditions) and acute encephalopathy (brain swelling/inflammation). Influenza can be fatal. Severe disease is most likely in people with chronic medical conditions, the elderly and women during the second half of pregnancy. Worldwide influenza causes 3-5 million cases of severe disease each year and 250,000 to 500,000 deaths.

How is influenza spread?

Influenza is very infectious and is easily passed from person to person. The virus is mainly spread by an infected person coughing or sneezing. The virus can also be spread through direct contact with an infected person or contaminated surfaces, particularly via the hands of healthcare workers.

When is a person with influenza contagious?

People generally develop symptoms 1-3 days after they are infected with the virus. Adults may be able to spread influenza to others from the day before getting symptoms through 5-7 days after symptoms start. Therefore, you may be able to spread influenza to other people, including patients, before you even know you have the flu. Children may be contagious for seven or more days.

How well does the vaccine work?

The vaccine is very effective (i.e., 70-90%) in preventing influenza among healthy people younger than 65 years of age. Although the vaccine may be less effective during years when the vaccine strains do not match the strains causing illness, the vaccine and circulating influenza strains are well matched in approximately 9 out of every 10 years. Even when the vaccine is not well matched to circulating strains it will usually provide some protection against severe disease and death.

Why should healthcare workers get the influenza vaccine?

As a healthcare worker you should get the influenza vaccine for two reasons: to protect yourself and protect your patients.

• Protect yourself
  As a healthcare worker you may have an increased risk of catching influenza. One study from Scotland found that healthcare workers were up to 10 times more likely to catch influenza than other people in the community. Even if you do not become very ill yourself with influenza you could spread the virus to other members of your family or household.
• Protect your patients
  All healthcare workers should get the influenza vaccine so they do not pass the virus to those at high risk for influenza-related complications, such as persons more than 50 years of age and those of any age with chronic medical conditions. This is particularly important for healthcare workers involved in the care of elderly patients, who may not get sufficient protection from the vaccine themselves. One study showed that vaccination of healthcare workers in an elderly care unit reduced the mortality rate among patients by almost 60%.

What are the side effects of the influenza vaccine?

Mild soreness and redness or swelling at the injection site are the most common side effects and may last one to two days. Other potential side effects, such as allergic reactions, are rare. There may be a one in a million risk of Guillain-Barré syndrome, a rare paralytic illness, though this only seems to have been a problem with the ?swine influenza? vaccine used in 1976.

Is it safe for pregnant women or women who are breast feeding to get the influenza vaccine?

Yes. As the vaccine only contains killed virus it is safe to use during pregnancy and it is safe for both mother and infant to get the vaccine if the mother is breast-feeding. Pregnant women have an increased risk of getting very severe disease if they catch influenza. The current National Immunisation Guidelines for Ireland recommend that "influenza vaccination should not be withheld from pregnant women in clinical risk groups who should receive influenza vaccination". 
These groups include persons with:
 - Chronic illness requiring regular medical follow-up e.g. chronic respiratory disease including moderate or severe asthma, chronic heart disease, chronic renal disease, chronic liver disease and diabetes mellitus
 - Immunosuppression due to disease or treatment including asplenia or splenic dysfunction.

Further information is available at http://www.hpsc.ie/hpsc/A-Z/VaccinePreventable/Vaccination/Publications/ImmunisationGuidelines

Can the influenza vaccine cause influenza?

No, the vaccine contains killed or inactivated influenza viruses and cannot cause influenza.

Are there people who should not get the influenza vaccine?

The vaccine can rarely cause an allergic reaction in people who have an allergy to egg protein. You should not have the vaccine if you have a known hypersensitivity (i.e. significant allergy) to eggs.

What should I do if I suspect influenza in a patient?

Make sure the doctor responsible for the patient's care and the infection control team are notified. The infection control team can recommend steps to limit the spread of influenza to other patients and staff and can look for additional cases of influenza. The patient?s doctor and the infection control team may decide to carry out laboratory tests for influenza and consider anti-influenza therapy.

What should I do if I get influenza symptoms?

Report your illness to your supervisor and to the occupational health services or infection control team at your institution. Avoid spreading infection to others by limiting contact with patients, washing your hands after contact with your respiratory secretions, and covering your mouth when coughing or sneezing.