SWINE FLU

The H1N1 “Swine Flu” Pandemic

 

The H1N1 or “swine flu” virus, which first appeared in April 2009, has gone on to become a worldwide "pandemic." This flu season, scientists expect both H1N1 flu and seasonal flu to cause more people to get sick than a regular flu season. More hospital stays and deaths may result, which makes vaccines that prevent influenza critical for optimal health of populations.

How Is 2009 H1N1 Flu Different From Regular (Seasonal) Flu?

 

Seasonal flu viruses change from year to year, but they are closely related to each other. People who have had flu infections in the past usually have some immunity to seasonal flu viruses (their bodies have built up some ability to fight off the viruses). The 2009 H1N1 flu virus is an entirely new virus strain. It is very different from seasonal flu viruses, and most people have little or no immunity to 2009 H1N1 flu. As a result, their bodies are not prepared to fight off the virus, possibly leading to serious complications.

The H1N1 “Swine Flu” Vaccine

 

This season, 2009 H1N1 vaccines are being made to protect against the H1N1 influenza virus. The U.S. government has purchased 250 million doses of 2009 H1N1 vaccine, so anyone who wants to get the vaccine will have the opportunity to do so. Vaccine will be made available as quickly as possible as it rolls off the production lines. Limited quantities of the vaccine began shipping in early October and availability will continue to increase through the end of the year and into 2010.

Why Are Swine Flu Vaccine Supplies Limited?

 Federal officials had projected that 40 million doses would be on hand by Oct. 15, but not even 13 million doses had arrived by the third week in October. According to Dr. Ciro Sumaya, a professor at the Texas A&M Health Science Center School of Rural Public Health and a member of the U.S. Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices, the H1N1 virus did not grow as quickly as expected during the half-century old -- and often-criticized -- egg-based production technique. He went on to explain that there have also been delays in the many steps before you get a vaccine that's available -- the production, the testing, the packaging, the allocation, and distribution. A top CDC official acknowledged that production of the vaccine was lagging, with a revised goal now of 50 million doses by mid-November and 150 million by year's end.

Isn't the 2009 H1N1 Swine Flu Vaccine Too New to Trust?

 

Is the swine flu vaccine brand new? Yes and no. The 2009 H1N1 swine flu vaccine is made exactly the same way as the seasonal flu vaccine, by the same manufacturers using the same materials. What has changed is the piece of the virus the vaccine uses to prime the immune system. Every couple of years or so, a new variant of a seasonal flu virus comes along. When that happens, a "new" vaccine is made using the relevant part of the variant virus. As shown on this slide, the CDC's Dr. Terrence Tumpey recreated the 1918 influenza virus in order to identify the characteristics that made this organism such a deadly pathogen. Research efforts such as this enable researchers to develop new vaccines and treatments for future pandemic influenza viruses.
Last year, some 100 million people got the seasonal flu vaccine and no safety issues appeared. There's no denying that the virus particle used in the vaccine has never been used before and there remains a remote possibility that a serious side effect might occur. But one can calculate that this possibility will be small and the expectation that the vaccine will prevent serious illness and deaths is very, very great.

What Types of Swine Flu Vaccines Are Being Produced?

 

There are two forms of 2009 H1N1 vaccines being produced: a 2009 H1N1 "flu shot" and the 2009 H1N1 nasal spray flu vaccine. The same manufacturers who produce seasonal flu vaccines are producing 2009 H1N1 vaccines for use in the United States, and the vaccines are being made in the same way that the seasonal vaccines are made.

2009 H1N1 Flu Shot

 

The H1N1 flu shot is an inactivated vaccine (containing “killed” virus) that is given with a needle, usually in the arm. The indications for who can get the 2009 H1N1 flu shot are the same as for seasonal flu shots. The flu shot is approved for use in people 6 months of age and older, including healthy people, people with chronic medical conditions, and pregnant women.

2009 H1N1 Nasal Spray Flu Vaccine

 

The H1N1 nasal spray, given via a nasal sprayer, is a vaccine made with live, weakened viruses that do not cause the flu (sometimes called LAIV for "live attenuated influenza vaccine"). The indications for who can get the 2009 H1N1 nasal spray vaccine are the same as for seasonal nasal spray vaccine. LAIV is approved for use in healthy people 2-49 years of age who are not pregnant. The nasal spray vaccine for use in the United States is being made by MedImmune, the same company that makes the seasonal nasal spray vaccine called FluMist.

Does the H1N1 Vaccine Require One or Two Shots?

 

Kids under 10 years of age will need two doses of the H1N1 swine flu vaccine, given three weeks apart. In kids over 10 years of age, the H1N1 swine flu vaccine works just as well as it does in adults requiring only one dose of the swine flu vaccine with protection expected in eight to 10 days following the shot. This is similar to seasonal flu vaccine.
It's likely that kids will be able to get their seasonal flu shots and their H1N1 swine flu shots on the same day, although clinical trials are still looking at the issue. The inhaled FluMist version of the swine flu vaccine cannot be given on the same day a kid gets the FluMist version of the seasonal vaccine. That's because FluMist contains a live, weakened flu virus and stimulates the immune system in a different way than flu shots, which contain inactivated virus particles.

If I Think I've Had Swine Flu, Do I Need the Vaccine?

 

It's important to realize that influenza vaccine cannot give you the flu. The injected flu shot contains inactivated (killed) viruses, and the nasal spray contains attenuated (weakened) viruses and cannot cause flu illness.
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 H1N1 swine 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 have already had swine flu.

When to Get Vaccinated?

 

Vaccination against 2009 H1N1 should begin as soon as vaccine is available and continue throughout the influenza season into December, January, and beyond. This is because the timing and duration of flu activity can vary. Flu seasons can last as late as April or May. By early October 2009, extensive 2009 H1N1 flu activity was being reported in the United States. It's possible that there may be waves of 2009 H1N1 activity during the 2009-2010 flu season that hit communities more than once over the course of the season. While 2009 H1N1 viruses are likely to be the most common cause of influenza this season, the CDC still expects that seasonal influenza viruses will circulate and continues to recommend that people get a seasonal flu vaccine to protect against seasonal flu viruses.

Who Should Get Vaccinated?

 

The CDC's Advisory Committee on Immunization Practices (ACIP), a panel made up of medical and public-health experts, recommends that programs and providers administer vaccine to people in the following five target groups (order of target groups does not indicate priority):

• pregnant women;
• people who live with or provide care for infants younger than 6 months of age (for example, parents, siblings, and day-care providers);
• health-care and emergency medical services personnel;
• people 6 months through 24 years of age; and
• people 25-64 years of age who have certain medical conditions that put them at higher risk for influenza-related complications. 

Why It Is Important to Get Vaccinated if You Are Pregnant?

 

Every pregnant woman knows that staying healthy is the best thing she can do to ensure her baby is healthy. Pregnant women are at an increased risk for swine flu and seasonal flu because expectant mothers have decreased lung capacity and changes in how their immune system works. These changes make pregnant women more susceptible to flu-related complications, including pneumonia and acute respiratory distress syndrome, endangering both mother and baby. Influenza's potential impact on the unborn child can be very serious as well, including spontaneous pregnancy loss, fetal death, preterm birth, and birth defects. Public-health and medical professionals are urging pregnant women to get vaccinated against both seasonal and H1N1 flu to protect themselves and their unborn babies. In fact, the CDC is urging pregnant women to be among those who get the first doses made available in their communities.
Pregnant women should get flu shots -- not the nasal spray vaccine -- since the nasal spray has not been approved for use in pregnant women. Women can receive the nasal spray vaccine after they have delivered, even if they are breastfeeding.

Who Should Not Be Vaccinated?

 

There are some people who should not get any flu vaccine without first consulting a physician. These include

• people who have a severe allergy to chicken eggs,
• people who have had a severe reaction to an influenza vaccination,
• people who developed Guillain-Barré syndrome (GBS) within six weeks of getting an influenza vaccine previously,
• children younger than 6 months of age (influenza vaccine is not approved for this age group),
• people who have a moderate to severe illness with a fever (they should wait until they recover to get vaccinated) , and
• people taking certain medications that suppress the immune system should not receive the “live” form of nasal spray vaccine.

H1N1 Swine Flu Vaccine Side Effects -- Flu Shot

 

The viruses in the flu shot are killed (inactivated), so you cannot get the flu from a flu shot. Some minor side effects that could occur are

• soreness, redness, or swelling where the shot was given;
• fever (low grade); and
• aches.

If these problems occur, they begin soon after the shot, are usually mild, and usually last one to two days. Almost all people who receive influenza vaccine have no serious problems from it. However, on rare occasions, flu vaccination can cause serious problems, such as severe allergic reactions.

H1N1 Swine Flu Vaccine Side Effects -- Nasal Spray

 

The viruses in the nasal-spray vaccine are weakened and do not cause severe symptoms often associated with influenza illness. (In clinical studies, transmission of vaccine viruses to close contacts has occurred only rarely.)
In children, side effects from LAIV can include

• runny nose,
• wheezing,
• headache,
• vomiting,
• muscle aches, and
• fever.

In adults, side effects from LAIV can include

• runny nose,
• headache,
• sore throat, and
• cough. 

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 altered to match a flu virus that has changed its genetic makeup. The same kind of alteration resulted in the H1N1 swine flu vaccine and 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 H1N1 swine flu vaccine causes 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.

Will the 2009 H1N1 Vaccines Contain Squalene or Adjuvants?

 

The 2009 H1N1 swine flu vaccine will NOT contain squalene or adjuvants in the United States. This may or may not be the case in other countries.
Squalene is 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 (a substance that helps and enhances the pharmacological effect of a drug or increases the ability of an antigen to stimulate the immune system).
According to current federal plans, only vaccines without adjuvants will be used in the United States during the 2009 flu season. This includes all of the 2009 H1N1 and seasonal influenza vaccines that will be available for children and adults in both the injectable and nasal spray formulations. None of these influenza vaccines will contain adjuvants.
The 2009 H1N1 vaccines with adjuvants are being studied to determine if they are safe and effective. Experts will review these data when they are available. There is no plan at this time to recommend a 2009 H1N1 influenza vaccine with an adjuvant.

Will the 2009 H1N1 Influenza Vaccine Contain Thimerosal?

 

The 2009 H1N1 influenza vaccines that the FDA is licensing (approving) will be manufactured in several formulations. Some will come in multi-dose vials and will contain thimerosal as a preservative. Thimerosal is a mercury-based preservative that has been used for decades in the United States in multi-dose vials of some vaccines to prevent the growth of microorganisms, such as bacteria and fungi, which may contaminate them after the vial is opened.
Some 2009 H1N1 influenza vaccines will be available in single-dose units, which will not require the use of thimerosal as a preservative. In addition, the live-attenuated version of the vaccine, which is administered intranasally (through the nose), is produced in single-units and will not contain thimerosal.

Is There a Link Between Guillain-Barré Syndrome (GBS) and Swine Flu Vaccines?

 

Guillain-Barré syndrome (GBS) is a rare disease in which the body damages its own nerve cells, causing muscle weakness and sometimes paralysis. It is not fully understood why some people develop GBS, but it is believed that stimulation of the body's immune system may play a role in its development. Infection with the bacterium Campylobacter jejuni, which can cause diarrhea, is one of the most common risk factors for GBS. People can also develop GBS after having the flu or other infections (such as cytomegalovirus and Epstein-Barr virus). On very rare occasions, people may develop GBS in the days or weeks following receiving a vaccination.

The 1976 Swine Flu Vaccine Wasn't Safe. Why Should I Trust This One?

 

The 1976 swine flu vaccine was linked to safety issues. Neal Halsey, MD, director of the Institute for Vaccine Safety at the Johns Hopkins Bloomberg School of Public Health, was at the CDC in those days. "We did identify an increased risk of GBS [Guillain-Barré syndrome] in the six weeks following immunization," says Halsey. No flu vaccine since then has been linked to this risk. Halsey thinks there is the potential for the H1N1 flu vaccine to carry a risk of causing one case of GBS per million people vaccinated. "The theoretical risk of that rare complication has to be balanced against the severity of the H1N1 flu," he says. "There already have been a lot of deaths, many in otherwise healthy, normal children. There is always a real risk from the flu, and a theoretical risk from the vaccines."
The 1976 H1N1 swine flu was a very different virus from the 2009 H1N1 swine flu, which combines elements from flu viruses that evolved in birds, humans, and pigs. And unlike the 1976 virus, the 2009 bug is causing a very real pandemic.

Are H1N1 Swine Flu Shots Mandatory?

 

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.
Healthcare 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 healthcare workers.

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. On October 24, 2009, President Barack Obama declared the H1N1 swine flu a national emergency.

Where Can My Children and I Get the Swine Flu Vaccine?

 

Medical practices and clinics that want to offer the H1N1 swine flu vaccine have already registered with their state health departments. You can check with your doctor to see if she or he is offering the vaccine. Because children are especially vulnerable to H1N1 swine flu -- and are especially likely to spread the disease to others -- many states will be offering H1N1 swine flu vaccinations in schools. In some states, permission slips already have been sent to parents.
Some states are also planning vaccinations at public sites. These plans will be announced locally. Different state, territory, and tribal health authorities have different plans. There is no one-size-fits-all plan; the CDC advises local health departments to adapt their H1N1 vaccination plans to local needs. That goes for retail chains as well. National retail outlets, such as pharmacy chains, may offer H1N1 swine flu vaccine in some areas but not in others.