WebMD provides a practical guide to the H1N1 swine flu vaccine.

A safe and effective H1N1 swine flu vaccine was created and produced in record time -- but it still wasn't ready when the U.S. pandemic peaked in early fall of 2009. Even so, by mid-December 2009, 28 million adults (13% of U.S. adults) and 18 million children (24% of U.S. children) had received the vaccine.

When seasonal flu vaccination begins for the 2010-2011 flu season, the regular flu vaccine will contain the 2009 H1N1 swine flu vaccine (as well as vaccines against the older H3N2 type A and type B flu bugs).

But the 2009 H1N1 flu bug is still here, popping up sporadically across the country. Moreover, there's no guarantee it will wait until winter to start spreading again. If it starts early in 2010 -- as it did in 2009 -- it will get here before the seasonal vaccine is ready.

Fortunately, there's still plenty of vaccine out there. Everyone, but particularly those at risk of serious flu complications (see below), should get the vaccine. And except for some places that charge a small administrative fee, it's still free.

While everybody hasn't been vaccinated, everybody has questions:

    * When can I get an H1N1 swine flu vaccination?
    * Is the H1N1 swine flu vaccine safe?
    * Who should get the H1N1 swine flu vaccine?
    * If I think I've had swine flu, do I need the vaccine?
    * What's the difference between the nasal spray and injectable vaccines?
    * I know science says vaccines preserved with thimerosal are safe, but is there an alternative?
    * I've heard that something called squalene is in the vaccine. Is that true?
    * How much will the H1N1 swine flu vaccine cost?
    * I've heard H1N1 swine flu shots are mandatory. Is that true?
    * Would YOU get the swine flu vaccine yourself

The answers are here:

 

When can I get an H1N1 swine flu vaccination?

Swine Swine flu vaccine remains available at many sites. The easiest way to find one is to type your ZIP code into the CDC's H1N1 vaccine locator, easily found in the CDC's H1N1 flu web site.

You can also check with your local health department to find vaccination locations in your area. And your doctor likely knows where to find vaccine in your area.

 

Is the H1N1 swine flu vaccine safe?

The H1N1 swine flu vaccine, both the shots and the nasal spray, are made the same way as the seasonal flu vaccine.

Every year or so, the seasonal vaccine -- which includes a component based on the seasonal H1N1 virus -- is tweaked to match a flu virus that has changed its genetic makeup. The same kind of tweaking resulted in the H1N1 swine flu vaccine.

That's why the FDA approved it: They considered it just a strain change, and not a brand new vaccine.

Even so, both long- and short-term clinical trials are under way. Results from the short-term studies already are here: Other than causing the usual soreness and perhaps redness at the site of injection, the vaccines cause no major side effects.

And like the seasonal flu vaccine, the H1N1 swine flu vaccine can't be taken by everybody. The vaccine is produced in hens' eggs, so people with egg allergies cannot take the vaccine.

Will there be long-term side effects? That's not likely -- but the CDC is taking no chances. The CDC and vaccine manufacturers have beefed up their safety monitoring process to look for anything unusual in people who get vaccinated against the new flu.

The most feared side effect of a flu vaccine is Guillain-Barre syndrome (GBS), a rare neurological condition that can result in paralysis and even death. Because the 1976 swine flu vaccine increased the risk of GBS, that vaccination program was aborted.

Seasonal flu vaccines slightly increase the risk of GBS by about one case per million people vaccinated. A June 2010 report from CDC found the 2009 H1N1 vaccine increased GBS risk by about the same amount: 0.8 cases per million people vaccinated.

An unprecedented level of safety monitoring -- including the military, an independent panel of experts, university campus health centers, and enhanced CDC surveillance -- has not revealed any unusual safety issues with the 2009 H1N1 flu vaccine.

 

Who should get the H1N1 swine flu vaccine?

Because it is a new virus to which humans have never before been exposed, everyone is vulnerable to H1N1 swine flu. That means everyone could benefit from the vaccine.

But certain groups are at particularly high risk of dangerous flu complications:

    * Children under age 5, especially those younger than 2 years old.
    * Adults age 65 and older
    * Pregnant women

In addition, certain medical conditions make it dangerous for a person to get the flu:

    * Asthma
    * Neurological and neurodevelopmental conditions including disorders of the brain, spinal cord, peripheral nerve, and muscle such as cerebral palsy, epilepsy (seizure disorders), stroke, intellectual disability (mental retardation), moderate to severe developmental delay, muscular dystrophy, or spinal cord injury  
    * Chronic lung disease (such as COPD and cystic fibrosis)
    * Heart disease
    * Blood disorders (for example, sickle cell disease)
    * Diabetes and other endocrine disorders
    * Kidney disorders
    * Liver disorders
    * Metabolic disorders
    * Weakened immune system due to disease or immune-suppressing therapy
    * People under age 19 on long-term aspirin therapy

If I think I've had swine flu, do I need the vaccine?

Even during a flu pandemic, colds and all kinds of flu-like illnesses circulate. In fact, most flu-like illnesses are NOT caused by the flu.

If you came down with a flu-like illness since April 2009, you may have had the H1N1 swine flu. But the only way to know for sure is if your doctor took a nasal or throat swab, sent it off to a lab, and had that lab confirm the infection.

If that didn't happen, it's not safe to assume you already had the flu. Especially if you're at risk of severe flu illness, it's a very good idea to get your H1N1 swine flu shot AND your seasonal flu shot. The vaccine is perfectly safe for people who actually had swine flu.

What's the difference between the nasal spray and injectable vaccines?

The traditional flu shot contains proteins separated from the flu virus. Those proteins can't cause illness. But your immune system learns to recognize them and mounts a protective reaction if a real live flu virus tries to infect you.

The FluMist nasal spray works differently. It contains a live flu virus that has been weakened to the point that it can't cause the flu. That sounds pretty scary, but millions of people have safely taken this kind of vaccine.

The advantage of the nasal spray is that in children who have never had the flu or a flu vaccine before, it seems to elicit a stronger immune response than the flu shot.

The disadvantage of the nasal spray is that in older people who've had the flu or flu vaccines before, it may not be quite as protective as the flu shot. That finding is based on a single study, based on just a single flu season. And since nobody has had the H1N1 swine flu before, the FluMist H1N1 swine flu vaccine is expected to work just as well in adults as the flu shot does.

 

I know studies show vaccines preserved with thimerosal are safe, but is there an alternative?

Tiny doses of a mercury compound called thimerosal keep multidose vials of flu vaccine safe from contamination with bacteria. Before thimerosal was added to multidose vials, contamination caused serious adverse events.

Exhaustive studies fail to find any reason to believe that thimerosal is unsafe. But if you don't want thimerosal, you don't have to have it. Single-dose syringes of flu vaccine don't need thimerosal and don't have any. Neither does the FluMist nasal spray vaccine.

If you prefer a thimerosal-free vaccine, check with your provider to see if one is available. If not, check with your state or local health department to see where you can find one.

I've heard that something called squalene is in the vaccine. Is that true?

None of the U.S. H1N1 swine flu or seasonal flu vaccines contains squalene.

Squalene isn't a very nice sounding word, but it's an oil that's a natural part of many body processes. It's widely used in cosmetics because it penetrates the skin easily without leaving an oily feel.

Squalene is also used in substances called adjuvants. When mixed with vaccines, adjuvants make vaccines work better at lower doses.

The U.S. purchased millions of doses of these adjuvants in case the H1N1 swine flu vaccine had to be boosted to be effective. That turned out not to be necessary. Unlike current H1N1 swine flu vaccines, a vaccine with adjuvant would have to be specifically approved by the FDA. Such vaccines could be used this year only under the FDA's Emergency Use Authorization. No such authorization has been issued.

However, adjuvants already are approved in Europe and other areas. They've been used safely in millions of people, although they may cause a bit more of a reaction at the site of injection that vaccines without adjuvant.

Vaccine makers likely will file for FDA approval of adjuvants, but this approval will be subject to rigorous safety analysis. In any case, no adjuvant will be used in any flu vaccine given in the U.S. this flu season.

 

How much will the H1N1 swine flu vaccine cost?

The U.S. government purchased the vaccine from manufacturers and is providing the vaccine at no cost.

The CDC has asked providers NOT to charge for administering the vaccine. Even if they do, several large insurance companies have said the costs would be covered.

 

I've heard H1N1 swine flu shots are mandatory. Is that true?

Swine flu shots are voluntary for most Americans. For those not in the military, there is no federal requirement to get the H1N1 swine flu vaccine.

Active-duty military personnel, National Guard troops on active duty, and civilian Defense Department employees in critical jobs will be required to get the vaccine.

Health care workers may be required by their employers to get vaccinated. The state of New York, for example, has mandated both seasonal and H1N1 swine flu vaccinations for all health care workers.

 

OK, you talk a good game. But would YOU get the swine flu vaccine yourself?

This WebMD reporter was a guinea pig in the swine flu clinical trial. You can watch me get my first shot.

What happened? Nothing. There wasn't even soreness at the site of injection. I did catch a cold (sniffles, cough, no fever, no muscle aches) about three weeks after my first shot -- unfortunately, flu shots don't protect against that. But I haven't had the flu, even though I live in a city (Atlanta) that's had a lot of cases.

 

 

Daniel J. DeNoon - WebMD