RadioBDC Logo
| Listen Live
< Back to front page Text size +

It's flu shot time! Answers to common questions.

Posted by Dr. Claire McCarthy  September 10, 2012 11:10 AM

E-mail this article

Invalid E-mail address
Invalid E-mail address

Sending your article

It's flu shot time! Just last week our clinic's supply arrived and we started giving it out. While most families are happy to get their child immunized, every year I talk to families who have questions and concerns about the influenza vaccine.

Here are the questions I'm most commonly asked:

My child is healthy. Why does he need this vaccine?
Over the years, I've come to have great respect for influenza and how sick it can make people--even healthy people. Yes, there's a chance that your child won't catch it--or that if he does catch it he won't get very sick. But there's also a chance that he will get very sick.

It's also important to vaccinate your children in order to protect other people. Your son may only have a mild case, but he could easily infect Grandma, or the neighbor with cancer, or your friend's newborn. By immunizing as many people as possible, especially young children, we keep everyone healthier.

Everyone should be immunized. But the people that the CDC most wants to get the vaccine include:
  • Children 6 months-4 years (because the young are more likely to get very sick, and are infection-spreaders)
  • People with asthma, heart disease, and other chronic health conditions--and any one with lowered immune defenses, like people on chemotherapy.
  • People on aspirin therapy
  • People older than 50.
  • Pregnant women 
  • Caregivers of children (especially children less than 6 months since they are too young to be immunized) or the elderly
  • Health care workers, and caregivers of people with health problems
Can't you catch the flu from the flu vaccine?
No. You can't. The shot has inactivated virus in it that can't cause an infection. The nasal spray, or LAIV (live attenuated influenza vaccine), is not completely inactivated--but it's been changed in a way that stops it from causing infection. There is a slight chance that LAIV could possibly cause an infection in someone with a weak immune system, which is why we don't recommend it for them or anyone who lives with them. 

Every year, scientists make their best guess as to which flu viruses are going to cause trouble--and usually, they are right. But occasionally they are wrong, and there are various flu viruses out there--so it's possible to get the flu shot and still get the flu. Also, it can take a couple of weeks after the shot for it to have it's full effect, so it's possible to catch the flu in that period (that's why it's good to get it early in the season!) But if you get it, it's a coincidence--it's not from the shot.

Aren't there dangerous side effects?
Every medical treatment has possible side effects, and the flu shot is no different. It's not uncommon to feel a bit achey and sick for a day or so after the shot, or even get a bit of a fever, and if you get a shot your arm may be sore. But more serious side effects are very rare.

Should my child get the nasal spray or the shot?
If your child has a health problem or is less than 2 years old, we recommend the shot. We have more experience with it, and it is a completely inactivated virus. But if your child is over 2 and healthy, the spray may even be slightly more effective--and most kids are happy not to get a needle. To learn more about LAIV, read the LAIV page of the CDC website.

Why does my baby need two flu shots?
For children under age 8 who have had less than two doses of flu vaccine since July 1, 2010, two doses are recommended to be sure they get enough protection. The second dose should be  given at least 4 weeks after the first.

What about preservatives?
Multidose vials of influenza vaccines (bottles that hold enough vaccine to immunize a bunch of people) contain a small amount of preservative (thimerosal) so that bacteria and other germs can't get into the vaccine once the bottle is opened, something that could be very dangerous. This small amount of preservative is felt to be very safe. Single dose vials, and LAIV, do not contain any thimerosal (nor do any of the vaccines we give children under the age of 6). 

To keep your family healthy this flu and cold season, teach your children to cover their coughs and sneezes--teach them to use the inside of their elbow rather than their hands, as hands often go on to touch things like doorknobs. And wash your hands, all the time! When using soap and water, sing the Happy Birthday song to be sure you're washing long enough; if you use hand sanitizer (make sure you always carry some with you), make sure that you use plenty and really rub it between your fingers.

If someone in your family has the symptoms of the flu (such as fever, cough, runny nose, vomiting, diarrhea or generally feeling lousy), call your doctor. In some cases, treatment with antiviral medication is a good idea.

Both the American Academy of Pediatrics and the Centers for Disease Control have lots of information about influenza and influenza vaccine on their websites. And talk to your doctor--he or she knows your situation, and is likely the best person to answer your questions.

This blog is not written or edited by or the Boston Globe.
The author is solely responsible for the content.

E-mail this article

Invalid E-mail address
Invalid E-mail address

Sending your article


About MD Mama

Claire McCarthy, M.D., is a pediatrician and Medical Communications Editor at Boston Children's Hospital . An assistant professor of pediatrics at Harvard Medical School and a senior editor for Harvard More »

More community voices

[an error occurred while processing this directive]

Child in Mind

Corner Kicks

Dirty Old Boston

Mortal Matters

On Deck

TEDx Beacon Street


Browse this blog

by category