Q&A: 2009 H1N1 influenza vaccine

Sunday, October 18, 2009

CENTERS for Disease Control and Prevention

When and how much of the 2009 H1N1 vaccine will be available?

Both the flu shot (in the arm) and nasal spray form of 2009 H1N1 vaccines have now been produced and licensed by the Food and Drug Administration. The federal government has purchased a total of 250 million doses of 2009 H1N1 vaccine. 2009 H1N1 vaccine was available starting early October, and approximately 40 million doses of licensed vaccine may be available by the end of October. Vaccine availability, however, depends on many factors, so these numbers will be frequently updated. The first doses of live attenuated 2009 H1N1 flu vaccine were administered Oct. 5. Administration of the 2009 H1N1 flu shot will began last week.

Will there be enough 2009 H1N1 flu vaccine for everyone who wants it?

It is expected that there will be enough 2009 H1N1 flu vaccine for anyone who chooses to get vaccinated. The federal government has procured 250 million doses of 2009 H1N1 flu vaccine. This quantity of vaccine accounts for the National Institutes of Health clinical trial data showing that children 6 months to 9 years of age will need two doses, and people 10 and older will need one dose.

Will the seasonal flu vaccine also protect against the 2009 H1N1 flu?

The seasonal flu vaccine is not expected to protect against the 2009 H1N1 flu.

Can the seasonal vaccine and the 2009 H1N1 vaccine be given at the same time?

Inactivated 2009 H1N1 vaccine can be administered at the same visit as any other vaccine, including pneumococcal polysaccharide vaccine. Live 2009 H1N1 vaccine can be administered at the same visit as any other live or inactivated vaccine except seasonal live attenuated influenza vaccine.

Who will be recommended to receive the 2009 H1N1 vaccine?

CDC's Advisory Committee on Immunization Practices has recommended that certain groups of the population receive the 2009 H1N1 vaccine when it first becomes available. These target groups include pregnant women, people who live with or care for children younger than 6 months of age, health care and emergency medical services personnel, people between the ages of 6 months and 24 years old, and people ages 25 through 64 years who are at higher risk for 2009 H1N1 because of chronic health disorders or compromised immune systems.

We do not expect that there will be a shortage of 2009 H1N1 vaccine, but availability and demand can be unpredictable. There is some possibility that initially the vaccine will be available in limited quantities. In this setting, the committee recommended that the following groups receive the vaccine before others: pregnant women, people who live with or care for children younger than 6 months of age, health care and emergency medical services personnel with direct patient contact, children 6 months through 4 years of age, and children 5 through 18 years of age who have chronic medical conditions.

The committee recognized the need to assess supply and demand issues at the local level. The committee further recommended that once the demand for vaccine for these target groups has been met at the local level, programs and providers should begin vaccinating everyone from ages 25 through 64 years. Current studies indicate the risk for infection among persons age 65 or older is less than the risk for younger age groups. Therefore, as vaccine supply and demand for vaccine among younger age groups is being met, programs and providers should offer vaccination to people older than 65.

Should I get vaccinated against 2009 H1N1 if I have had flu-like illness since the spring of 2009?

The symptoms of influenza (flu-like illnesses) are similar to those caused by many other viruses. Even when influenza viruses are causing large numbers of people to get sick, other viruses are also causing illnesses. Specific testing, called RT-PCR test, is needed in order to tell if an illness is caused by a specific influenza strain or by some other virus. This test is different from rapid flu tests that doctors can do in their offices. Since most people with flu-like illnesses will not be tested with RT-PCR this season, the majority will not know whether they have been infected with 2009 H1N1 flu or a different virus.

Therefore, if you were ill but do not know if you had 2009 H1N1 infection, you should get vaccinated, if your doctor recommends it. So, most people recommended for 2009 H1N1 vaccination should be vaccinated with the 2009 H1N1 vaccine regardless of whether they had a flu-like illness earlier in the year. If you have had 2009 H1N1 flu, as confirmed by an RT-PCR test, you should have some immunity against 2009 H1N1 flu and can choose not to get the 2009 H1N1 vaccine. However, vaccination of a person with some existing immunity to the 2009 H1N1 virus will not be harmful.

Any immunity from 2009 H1N1 influenza infection or vaccination will not provide protection against seasonal influenza. All people who want protection from seasonal flu should still get their seasonal influenza vaccine.

Do those who have been previously vaccinated against the 1976 swine influenza need to get vaccinated against the 2009 H1N1 influenza?

The 1976 swine flu virus and the 2009 H1N1 virus are different enough that its unlikely a person vaccinated in 1976 will have full protection from the 2009 H1N1. People vaccinated in 1976 should still be given the 2009 H1N1 vaccine.

Where will the vaccine be available?

Every state is developing a vaccine delivery plan. Vaccine will be available in a combination of settings such as vaccination clinics organized by local health departments, health care provider offices, schools and other private settings, such as pharmacies and workplaces.

Will this vaccine be made differently than the seasonal influenza vaccine?

No. This vaccine will be made using the same processes and facilities that are used to make the currently licensed seasonal influenza vaccines.

Are there other ways to prevent the spread of illness?

Take everyday actions to stay healthy.

* Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.

* Wash your hands often with soap and water, especially after you cough or sneeze. If soap and water are not available, use an alcohol-based hand rub.

* Avoid touching your eyes, nose or mouth. Germs spread that way.

* Stay home if you get sick. CDC recommends that you stay home from work or school and limit contact with others to keep from infecting them.

Follow public health advice regarding school closures, avoiding crowds and other social distancing measures. These measures will continue to be important after a 2009 H1N1 vaccine is available because they can prevent the spread of other viruses that cause respiratory infections.

Will two doses of vaccine be required?

The U.S. Food and Drug Administration has approved the use of one dose of 2009 H1N1 flu vaccine for people 10 years of age and older. This is slightly different from CDC's recommendations for seasonal influenza vaccination, which states that children younger than 9 who are being vaccinated against influenza for the first time need to receive two doses. Infants younger than 6 months of age are too young to get the 2009 H1N1 and seasonal flu vaccines.

What will be the recommended interval between the first and second dose for children 9 years of age and under?

CDC recommends that the two doses of 2009 H1N1 vaccine be separated by four weeks. However, if the second dose is separated from the first dose by at least 21 days, the second dose can be considered valid.

Are natural remedies (also referred to as "complementary" or "alternative" medicine) recommended to prevent the 2009 H1N1 flu virus?

The first and most important step to prevent the flu is to get vaccinated. Vaccination stimulates an immune response using a killed or weakened virus that uses the body's own defense mechanisms to prevent infection. CDC's current recommendations to protect against 2009 H1N1 virus do not include natural remedies as a sole prevention method. If you want to use a natural remedy to reduce symptoms, CDC recommends that you talk to your health care provider about options.

Alternative medicine should not be used as a replacement for proven conventional care, or to postpone seeing a doctor about a medical problem.

The National Institutes of Health provides information at health.nih.gov on specific alternative options, including scientific information, potential side effects and cautions for each.

The Federal Trade Commission warns consumers to be cautious about products that claim to prevent, treat or cure 2009 H1N1 influenza, specifically products like pills, air filtration devices and cleaning agents can kill or eliminate the virus.

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