Flu: Frequently Asked Questions

Updated: April 4, 2013

For basic information on flu, including prevention, read our fact sheet. For specific questions, see below. If your question isn't answered here, ask it.

Is this year's flu vaccine a good match for the viruses that we are seeing?
Will my child need one or two doses of the vaccine?
Who can receive the FluMist?
Is the spray or shot more effective?
How long will the flu shot's effectiveness last?
Will the flu vaccine give me the flu? 
What are the side effects of the flu vaccine?
How much does the vaccine cost?
If I am ill, will I be able to receive the vaccine?
Will you absolutely not get the flu if you get the vaccine?
What is Guillain-Barré syndrome and what are the risks associated with it and vaccinations?
I have concerns about the use of thimerosal. Is thimerosal still being used?
Can a breastfeeding mom receive the flu shot or nasal spray?
I've heard that the flu vaccine is effective only half the time. Is that true?


Questions about vaccines

How can I get the flu vaccine?
The Health Department will offer a limited number of doses of flu vaccine by appointment at its four county health centers. Please call the health center in the county where you live to schedule an appointment, though the appointment can be at any health center.

Many doctors' offices and pharmacies are offering the flu vaccine as well.

Is this year's flu vaccine a good match for the virus that we are seeing?
Most cases of flu reported so far seem to be a good match for the vaccine, according to the CDC 91% of specimens tested match one of the three strains in this year’s vaccine.

Will my child need one or two doses of the vaccine?
Typicallly, children aged 6 months through 8 years require two doses of influenza vaccine during their first season of vaccination (administered a minimum of four weeks apart) to optimize immune response.

Who can receive the FluMist vaccine?
The FluMist is recommended for the healthy children, adolescents and adults (aged 2 through 49 years) except for pregnant adolescents and adults

Is the spray or shot more effective?
In the past, most healthy individuals 2-49 years of age had a robust response to either vaccine. For the older population, the shot seems to be more effective. 

Will the flu vaccine give me the flu?
The viruses in the flu shot are killed (inactivated), so you cannot get the flu from a flu shot. The FluMist contains live (activated) viruses, but they are weakened and do not cause severe symptoms often associated with flu.

What are the side effects of the flu vaccine?
For the shot, some minor side effects that could occur are soreness, redness, or swelling where the shot was given; low grade fever; and aches. In children, side effects of the FluMist that could occur are runny nose, wheezing, headache, vomiting, muscle aches and fever. For adults, side effects of the FluMist that could occur are runny nose, headache, sore throat and cough.

If I am ill, will I be able to receive the vaccine?
Anyone who is moderately or severely ill (including those who've had a fever within the last 24 hours) might be advised to wait until he/she recovers before getting the vaccine. If you have a mild cold or other illness, there is usually no reason to wait. 

Will you absolutely not get the flu if you get the vaccine?
Unfortunately, some people who are vaccinated against the flu may still get sick. However, it usually is a milder case. Some reasons why a person may become ill:

• People may be exposed to a flu virus shortly before getting vaccinated or during the 2-week period it takes the body to gain protection.

• A person may be exposed to a flu virus that is not included in the seasonal flu vaccine. Each year’s vaccine protects against the 3 viruses that research suggests will be most common.

• Flu vaccination is not a perfect tool, but it is the best tool currently at our disposal to prevent the flu

What is Guillain-Barré syndrome and what are the risks associated with it and vaccinations?
Guillain-Barré syndrome is a rare disorder in which a person’s own immune system damages the nerve cells, causing muscle weakness and sometimes paralysis. GBS can cause symptoms that last for a few weeks or several months. Most people recover fully from GBS, but some people have permanent nerve damage. In rare cases, people have died of GBS, usually from difficulty with breathing. In the United States, for example, an estimated 3,000 to 6,000 people develop GBS each year on average, whether or not they received a vaccination. This is about one to two cases of GBS per 100,000 people.

Scientists first reported a suspected link between GBS and vaccinations in 1976, during a national campaign to vaccinate people against a swine flu virus. The investigation found that vaccine recipients had a higher risk for GBS than those who were not vaccinated (about one additional case occurred per 100,000 people vaccinated). Given this association, and the fact that the swine flu disease was limited, the vaccination program was stopped. Since then, numerous studies have been done to evaluate if other flu vaccines were associated with GBS. In most studies, no association was found, but two studies suggested that approximately 1 additional person out of 1 million vaccinated people may be at risk for GBS associated with the seasonal influenza vaccine. GBS has not been an issue in the ongoing swine flu vaccine trials.

I have concerns about the use of thimerosal. Is thimerosal still being used?
Since 2001, no new vaccine licensed by FDA for use in children has contained thimerosal as a preservative, and all vaccines routinely recommended by the CDC for children under 6 years of age have been thimerosal-free, or contain only trace amounts, except for multi-dose formulations of influenza vaccine. This was done as a precautionary step and not because there was evidence confirming that thimerosal-containing vaccines were causing health problems. The most recent and rigorous scientific research does not support the hypothesis that thimerosal-containing vaccines are harmful.  

Thimerosal is an important preservative that protects vaccines against potential microbial contamination, which may occur in opened multi-dose vials of vaccine. Such contamination could cause serious illness or death. Since seasonal influenza vaccine is produced in large quantities for annual immunization campaigns, some of the vaccine is produced in multi-dose vials and contains thimerosal to safeguard against possible contamination of the vial once it is opened.

Can a breastfeeding mom receive the flu shot ?
Yes. Both seasonal flu vaccines should be given to breastfeeding mothers. Breastfeeding is fully compatible with flu vaccination and preventing the flu in mothers can reduce the chance that the infant will get the flu. Also, by breastfeeding, mothers can pass on to the infant the antibodies that their bodies make in response to the flu shots, which last for six months and can reduce the infant’s chances of getting sick with the flu. This is especially important for infants less than 6 months old who have no other way of receiving vaccine antibodies, since they are too young to be vaccinated.

I've heard that the flu vaccine is effective only half the time. Is that true?
The flu vaccine continues to be one of the best ways to protect ourselves against the flu. It is true that current influenza vaccines have limitations in terms of how well they work, including how well they work to protect different groups of people. Additionally, how well the flu vaccine works (i.e., its ability to prevent flu illness) can range widely from season to season and can also vary depending on the health and age of the person being vaccinated.

The Health Department encourages Northern Kentucky residents to continue to be vaccinated against the flu, and to also take other measures to prevent the spread of illnesses, such as washing hands frequently, covering coughs/sneezes and staying home when sick.

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