Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started
My Medicine

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Vaccines Health Center

Font Size

Flu Vaccine FAQ

What the CDC Wants You to Know About the 2010-2011 Flu Vaccine

I hear the H1N1 swine flu vaccine is included in the seasonal vaccine. Doesn't that make the seasonal vaccine much less safe? continued...

Our monitoring showed the side effects of the H1N1 vaccine were pretty much the same as you'd see from regular seasonal vaccines. There was no indication the pandemic vaccine was any less safe than any vaccine we've ever produced.

So including that vaccine as one of the three in this year's seasonal vaccine will not change the safety pattern. Even so, we will monitor the safety of this year's seasonal vaccine closely-- as we always do.

My children are under 9 years old. How many doses of the seasonal flu vaccine do they need?

It's really quite complicated for parents whose children are 8 years old or younger and who have never been fully vaccinated against the flu.

How many doses of flu vaccine will a child under age 9 years need this year? It will depend on two things:

  • Whether the child got any H1N1 vaccine AND
  • Whether the child previously got a seasonal vaccination, when that was given, and how many doses they got.

Children who got a previous seasonal flu vaccine as recommended -- AND got just one dose of the H1N1 pandemic vaccine last year -- need only one dose of the seasonal vaccine this year. We give them credit for getting the priming dose last year, but only if they previously got the seasonal vaccine.

Children under age 9 years who never before got a seasonal flu vaccination will need two doses of the seasonal vaccine this year -- even if they got the 2009 H1N1 pandemic flu vaccine.

Children under age 9 years who have had a previous flu vaccination but who did not get the 2009 H1N1 pandemic flu vaccine will need two doses of the seasonal vaccine this year.

If a child needs two doses of the flu vaccine, the second dose must be given no sooner than four weeks after the first dose.

It's such a hassle to get young children two doses of flu vaccine a month apart. Won't they get at least some protection from a single dose of the vaccine?


This year, the number of doses is driven by the pandemic virus component of the vaccine. Studies at the National Institutes of Health show that children do not respond well to a single dose of the 2009 H1N1 vaccine. A single dose does not provide protection to a very large number of young children.

We are not just making this up. The data show two doses are absolutely necessary. Yes, it can be a hassle to take them back a month later for their second dose -- but it greatly improves the chances the child will be protected.

Today on WebMD

passport, pills and vaccine
25 ways to protect yourself from illness.
syringes and graph illustration
Create a personalized schedule.
flu shot signage
Get answers to your questions
gloved hand holding syringe
Which ones do you need?
woman walking
Vaccine Schedule Are Your Childs Shots Up To Date
69x75 thumbnail early pregnancy 02
gloved hand holding syringe
adult vaccine injection
woman peeking under sheets
cold season and vitamin C
Adult Meningitis Vaccines What You Should Know