News Releases > Questions and Answers regarding H1N1 vaccine
What is the difference between the H1N1 injectable and the H1N1 nasal spray vaccine?
There are two types of H1N1 flu vaccine being produced:
The injectable vaccine (called inactivated vaccine because it has killed virus in it) is injected into the muscle, like the annual flu shot. It is approved for use in people 6 months of age and older, including healthy people, people with chronic medical conditions and pregnant women. If you are moderately or severely ill, you might be advised to wait until you recover before getting the vaccine. If you have a mild cold or other illness, there is usually no need to wait.
The nasal spray vaccine (called LAIV for Live Attenuated Influenza Vaccine) is a vaccine made with live, weakened viruses that cannot grow at normal body temperature and is given via a nasal sprayer. It is approved for use in healthy people ages 2 years to 48 years who are not pregnant. The vaccine virus is attenuated (weakened) so it will not cause illness. If you have any nasal congestion, you will need to wait to get the vaccine.
About 2 weeks after vaccination, antibodies that provide protection against 2009 H1N1 influenza virus infection will develop in the body.
How safe and effective is the H1N1 vaccine?
The H1N1 vaccines are made just like seasonal flu vaccines. They are expected to be as safe and effective as seasonal flu vaccines. They will not prevent “flu-like” illnesses caused by other viruses.
Which type of H1N1 vaccine is more effective?
Both vaccines are expected to be effective against 2009 H1N1 virus
Are there any risks to getting the vaccine?
A vaccine, like any medicine, could cause a serious problem, such as a severe allergic reaction. But the risk of any vaccine causing serious harm, or death, is extremely small. If you should experience any signs of a severe reaction, such as high fever, difficulty breathing or behavior changes, call a doctor right away.
What side effects are associated with the H1N1 vaccine?
With the nasal spray vaccine, side effects can include runny nose, headache, cough, and sometimes fever in children. With the injectable vaccine, there may be a slight fever or body aches and some soreness at the injection site. This usually goes away in a day or two.
Does the H1N1 vaccine contain thimerosal?
The nasal spray vaccine does not contain thimerosal or other preservatives. Some injectable vaccine contains thimerosal. Some people have suggested that thimerosal might be related to autism. In 2004 a group of experts at the Institute of Medicine reviewed many studies looking into this theory, and found no association between thimerosal and autism. Additional studies since then reached the same conclusion.
Who should not get the H1N1 vaccine?
You should not get 2009 H1N1 vaccine if you have a severe (life-threatening) allergy to eggs, or to any other substance in the vaccine. Talk to your doctor if you have had bad reactions to flu vaccine in the past.
Children younger than six months of age can not get a flu vaccine.
Can breastfeeding mothers get the H1N1 nasal spray vaccine?
It is not known whether Influenza A (H1N1) 2009 Monovalent Vaccine Live, Intranasal or FluMist is excreted in human milk. Therefore, as some viruses are excreted in human milk and additionally, because of the possibility of shedding of vaccine virus and the close proximity of a nursing infant and mother, the manufacturers recommend that caution be exercised if H1N1 FluMist is administered to nursing mothers. However the injectable H1N1 vaccine can be administered to pregnant women and nursing mothers.
Can the H1N1 vaccine be given to people when they are ill?
The nasal spray flu vaccine can be given to people with minor illnesses (e.g., diarrhea or mild upper respiratory tract infection with or without fever). However, if nasal congestion is present that might limit delivery of the vaccine to the nasal lining, then a person should wait to get the vaccine. The injectable vaccine should not be given to people who are moderately to severely ill with a fever.
Should I get vaccinated against 2009 H1N1 even if I have had a flu-like illness this year?
The symptoms of influenza (flu-like illnesses) are similar to those caused by many other viruses. Even when flu viruses are causing large numbers of people to get sick, other viruses are also causing illnesses. Since most people with flu-like illnesses will not be tested for H1N1 this season, the majority will not know whether they were infected with 2009 H1N1 flu or a different virus. If a person was ill but it was not confirmed as 2009 H1N1 infection, the person should still get vaccinated if a doctor recommends it.
Will the H1N1 vaccine protect me against seasonal flu?
The H1N1 vaccine will not prevent seasonal flu. You should also get a seasonal influenza vaccine when it is available to protect you from seasonal flu.
What is the recommended interval between the first and second dose for children 9 years of age and under?
The U.S. Centers for Disease Control and Prevention recommends that the two doses of 2009 H1N1 vaccine be separated by 4 weeks.
Can the 2009 H1N1 nasal spray vaccine and the seasonal nasal spray vaccine be given at the same time to the same person?
No. The seasonal nasal spray vaccine and the 2009 H1N1 nasal spray vaccine should not be given at the same time. This is because the nasal spray vaccines might not be as effective if given together. It is fine to receive the 2009 H1N1 nasal spray at the same time as the seasonal influenza (flu) shot, or the seasonal flu nasal spray at the same time as the 2009 H1N1 flu shot vaccine.
Do those that 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 it’s 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.
When is it too late to get the H1N1 vaccine?
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 influenza season. Our typical flu season peaks in January or February but can last as late as May.