This is an update written on October 1 to an article previously published on September 18, 2009.
The H1N1 flu vaccine will be available to the US public around October 6. Influenza activity, much of it H1N1, has been increasing the past few weeks in the US, so this is welcome news for all of us: individuals now have an option for protection from an unpleasant illness, health care providers have a new treatment to offer their patients, and anti-vaccine wingnuts finally have some fresh material. Here’s some answers to common questions about the H1N1 vaccine.
What is the H1N1 flu vaccine and is it different from the seasonal flu vaccine?
The H1N1 vaccine and the seasonal flu vaccine are two separate vaccines against different viruses. Health care professionals recommend that certain people get both vaccines.
The H1N1 vaccine protects only against the new H1N1 influenza virus, which is the cause of swine flu. It does not protect against other strains of seasonal flu. The seasonal flu vaccine, offered every year, provides protection against an additional three common influenza viruses. Both vaccines are expected to reduce illness, limit hospitalizations, and potentially save lives.
When will the H1N1 flu vaccine and the seasonal flu vaccine be available?
According to the CDC, the first doses of the H1N1 vaccine will ship in early October and be available to the public around October 6. This initial version is the nasal spray. The injectable vaccine will ship soon after.
The seasonal flu vaccine is already available, as a nasal spray and as an injection.
What is the difference between the injected H1N1 vaccine and the nasal spray H1N1 vaccine?
The injected H1N1 vaccine contains viral proteins-it does not contain an actual live virus. The nasal spray contains live, weakened virus.
Due to production issues, the nasal spray vaccine will be available before the injectable vaccine. Unfortunately, since the nasal spray vaccine contains a live virus, it is only recommended in healthy individuals between the ages of 2 and 50. People older than 50 and people with chronic underlying medical conditions should wait for the injectable vaccine.
Who should get the H1N1 flu vaccine?
Vaccine experts recommend that high-risk groups get vaccinated against the illness. This includes:
● Pregnant women
● Healthcare providers
● People aged 6 months through 24 years
● People who are around infants less than 6 months old
● Anyone with a chronic health condition that increases their risk of severe illness. Such chronic conditions include but are not limited to asthma, heart disease, emphysema, diabetes, and a weakened immune system.
This includes about 159 million Americans, chances are good you’re one of them.
Though the focus should be on high-risk groups, experts recommend that anyone who wants the vaccine should get it, provided there is enough leftover supply for the general population.
Who should not get the H1N1 flu vaccine?
Anyone with an allergy to eggs should not receive the vaccine, since chicken eggs are used in the manufacturing process for both the nasal spray and the injectable vaccine. Children less than 6 months should not get the vaccine (instead, people around them should get the vaccine so they are protected).
For adults over 65, the seasonal flu vaccine is highly recommended, but the recommendation for H1N1 vaccine is not as strong. For reasons that are currently unclear, older adults are less likely to suffer severe illness from H1N1 as compared to younger adults, perhaps due to a certain amount of immunity from prior exposure decades ago.
Who should receive the H1N1 injection vaccine instead of the nasal spray vaccine?
Basically, healthy people between the ages of 2 and 50 can get the nasal spray, anyone else should get the injection. Especially if you have a weakened immune system, you should not receive the live virus nasal spray; get the injection with the killed virus instead. Children who need long term aspirin therapy, such as for conditions like Kawasaki disease, should also receive the injection instead of the nasal spray.
Can I get the H1N1 flu vaccine at the same time as the seasonal flu vaccine?
You can get both injections at the same time. However, if you’re using the nasal spray, you should separate the two by about one month.
How many doses of the H1N1 vaccine do I need?
Adults need just one dose of the vaccine. Children under 10 years need 2 doses separated by a month in order to get a good immune response.
What are the side effects of the H1N1 vaccine?
Similar to the seasonal flu vaccine, the most common side effects of this injectable vaccine are pain at the injection site, muscle aches, headaches, and malaise. Rarely, patients might suffer severe allergic reactions to the vaccine.
The nasal vaccine’s side effects include runny nose, sore throat, and fevers-symptoms that resemble a very mild case of the flu, but are not nearly as severe or long-lasting as a real influenza infection.
The best data about this vaccine come from two studies recently published in the New England Journal of Medicine. Several hundred adult patients who received the vaccine have been followed for months, and initial data was published several weeks after vaccination. No serious short-term side effects were found in any of those patients.
Since the nasal spray vaccine is a live virus, can I catch the flu from it?
No. The nasal spray vaccine contains live, attenuated viruses that are cold-adapted. This means that they can live in the relatively cooler temperatures of the nose, but not warmer places deep in the body, such as in the lungs. Because they are limited to the nose, the effects of the virus are mild. Some people do get side effects that resemble a very weak, short-lived flu, but are nowhere near as serious as a real influenza infection.
Will getting the seasonal flu vaccine increase my risk of catching swine flu?
It’s unlikely. Media in Canada are reporting on a study purportedly showing that individuals who got the flu shot in 2008 are more likely to catch H1N1 in 2009. This study has not been published in any scientific journal, so no one knows if it’s accurate. According to Dr. Thomas Freiden from the CDC, investigators have closely looked at data from New York and Australia for similar results, and no increased risk was seen. At this point, all the reliable data and studies that have been published do not show any increased risk of catching swine flu after getting the seasonal flu vaccine.
What is the current status of research on H1N1 vaccine?
As of September 30, several studies of hundreds of healthy adult patients have been published. Research is ongoing in children and pregnant patients.
The H1N1 vaccine is manufactured using the same process as the seasonal flu vaccine, by the same manufacturers in the same factories. Years of research with the seasonal flu vaccine, including research in pregnant patients and children, have shown it to be extremely safe.
What is Guillain Barre Syndrome and why are people talking about it when they’re talking about the H1N1 flu vaccine?
Guillain Barre Syndrome is a rare neurological illness with symptoms ranging from mild muscle weakness to complete paralysis. While most people recover, some people die from the illness. Triggers for the disease include infections, most commonly by a bacteria called Campylobacter.
The influenza virus itself can also cause Guillain Barre Syndrome, and there is some debate about whether the seasonal influenza vaccine causes the disease. If the vaccine does increase the risk, the increase is very slight at about one case per million people vaccinated. The odds of developing a severe complication such as pneumonia from an influenza infection are higher than that, so even if the vaccine does cause Guillain Barre Syndrome, you’re better off getting the seasonal flu vaccine.
Unlike the controversial link between the Guillain Barre Syndrome and the seasonal influenza vaccine, there is a likely association between the syndrome and a previous swine flu vaccine. According to the CDC, the 1976 swine flu vaccine caused about one case of Guillain Barre Syndrome for every 100,000 people vaccinated.
The 1976 swine flu vaccine which resulted in an increased risk of Guillain Barre Syndrome was manufactured using different techniques than the current H1N1 vaccine. Since the current H1N1 vaccine is produced with the same process as the seasonal influenza virus, the risk of Guillain Barre Syndrome is thought to be similar to the very low or negligible risk from the seasonal influenza vaccine.
Is mercury (thimerosal) included in the vaccines?
Some, but not all, of the batches of H1N1 vaccine are thimerosal-free.
Thimerosal is a mercury compound that is added to multi-dose vials of influenza vaccines to prevent bacterial contamination of the medication. Some groups have questioned whether mercury in vaccines plays a role in the development of autism, but scientific studies have shown no correlation between thimerosal and autism.
Are adjuvants included in the H1N1 vaccines?
No. None of the current H1N1 vaccines marketed in the US contain adjuvants.
Adjuvants are additional materials that are added to the antigen in a vaccine to make it more effective. Adding these materials, such as small doses of aluminum, will increase your body’s immune response to the vaccine.
I’ve already had H1N1, should I get the vaccine? If I do, will it harm me?
If you’ve already had H1N1, there’s no point in getting the vaccine. However, if you do get the vaccine, it will not harm you-on the other hand, it won’t help either.
Many people have had flu-like symptoms over the past several months and wonder if it was H1N1, realizing that if it was, there’s no point to getting the H1N1 vaccine. Since most people who have had upper respiratory infections in the past few months did not actually have H1N1, the CDC is recommending that they still get the vaccine against H1N1. This is especially true for people in one of the high-risk groups mentioned above.
H1N1 doesn’t seem to be that lethal, I’m young and healthy, should I really get the H1N1 vaccine?
The CDC recommends that young, healthy people get the vaccine if there is supply available after vaccinating high-risk groups. Overall, H1N1 does not appear to be particularly more deadly than the seasonal flu, but there is a higher rate of infection in younger people. It also appears that young, healthy people make up a higher percentage of the deaths from H1N1 than is typical for seasonal flu. While the chances of you dying from this disease are small, the chances that you will get infected and sick enough to stay home from school or work for a few days is much higher. The vaccine could prevent both illness and death.
You’ll have to weigh these known benefits from the vaccine versus the unknown risks. Initial studies of a few hundred adults have shown no danger from the vaccine in the short-term. In the long-term, since the vaccine is made using the same techniques as the seasonal flu vaccines, the H1N1 vaccine is expected to be equally safe.
Is it possible that these recommendations will change?
Yes. While the CDC’s recommendations are based on the best evidence available, the H1N1 situation is fluid and new recommendations might be made as more information is known.
Should the virus suddenly become more lethal, the recommendation to vaccinate young, healthy adults will become stronger. If the rates of H1N1 infection are declining in the US by the time the H1N1 vaccine is introduced, the recommendation to vaccinate might become weaker. I will continue to update this webpage as more is learned.
Gregg A. Miller says:
This post and prior comments were updated October 1st. Jason and Colleen, if you didn't see answers to your questions before I took down the prior version of the post, please let me know and I'll post answers here.
I welcome all comments. If you post a link to a website, your comment requires moderation and I don't frequently moderate. It might take a week or two to show up, if ever. If there are no links, your comment should appear almost immediately.
Gregg A. Miller says:
I should also say, if you're looking for individualized advice as to whether or not you should take this vaccine, I'm afraid I can't give that. Please have a face-to-face conversation with your health care provider; I hope the general information in this post can help you make an informed decision.
you says:
You are insane to think we should get this shot. It is untested and contains variables harmful to health. You should lose your license to practice. http://www.medicalvoices.org/en/vaccination/articles/the-truth-about-the-flu-shot.html
Jeff says:
"Guillain Barre Syndrome is a rare neurological illness..."
Which was rarer? Dying from the '76 swine flu, or dying from Guillain Barre as a result of getting the flu shot? I'm interested in the precise numbers if you have them.
Gregg A. Miller says:
You,
The link you provide completely distorts the facts and quotes research out of context.
I encourage everyone to click on it and then go to www.cochrane.org to find the original summaries, which have been warped by the medicalvoices website. For example, You's link claims that the flu vaccine is not effective for elderly living in the community. In fact, this Cochrane review notes that well-matched flu vaccine is effective for reducing hospitalizations, pneumonia, and death. Overall the original authors found that flu vaccine prevents death in the elderly, that it was most effective in the most vulnerable of patients (nursing home patients), and that it is obviously more effective when it was well-matched to the year's circulating strains.
Gregg
link to original abstract: http://www.mrw.interscience.wiley.com/cochrane/clsysrev/articles/CD004876/frame.html
Gregg A. Miller says:
Jeff,
Interesting question. I've seen different quotes. However, I most frequently read that one patient died of swine flu in 1976 and about two or three dozen died from Guillan-Barre syndrome linked to the 1976 vaccine. The 1976 swine flu 'epidemic' has been called "The Epidemic that Never Was," as experts had predicted it might be as serious as the 1918 flu, but the disease just fizzled out.
So here's how the conversation between two reasonable people about this vaccine goes:
*Anti-vaccine person*: I don't want the 2009 H1N1 vaccine because in 1976 it killed more people than it saved.
*Pro-vaccine person*: Actually, swine flu in 1976 is a totally different disease than in 2009, the current epidemic has killed thousands and sickened millions, so the benefit of the vaccine is much higher now in 2009.
*AVP*: Even if it's more beneficial now, I still don't want it given the risk I'll die from swine flu is so minimal and there's a risk that I'll get Guillan Barre Syndrome from the H1N1 vaccine.
*PVP*: The risk of Guillan Barre Syndrome is much smaller with the 2009 vaccine, since it's made using the same techniques and in the same factories as the regular flu vaccine. The regular flu vaccine's risk of Guillan Barre Syndrome is miniscule to non-existent.
*AVP*: They thought the 1976 swine flu vaccine was safe too, and look what happened.
*PVP*: Well, we have more proof that the 2009 H1N1 vaccine is safe, given that it's made exactly the same way as the seasonal flu vaccine.
Will AVP die, or will PVP come down with some unpredictable side effect? We'll know in a few months...
Gregg
Nick says:
Hi Gregg,
Thank you so much for this blog. Really helps at taking a decision about the vaccine for me and my family.
Question: from all the issues raised by naysayers about the vaccine, does any of them ( thimersola, formaldehyde etc... ) remains if we talk about the spray virus?
Thanks
Nick
Gregg A. Miller says:
Hi Nick,
I’m really glad you find this information useful, I hope it helps you make a decision. The nasal vaccine doesn’t mention thimerosal/mercury or other preservatives.
For the live Flumist nasal spray vaccine insert, check out the FDA website: http://www.fda.gov/downloads/BiologicsBloodVaccines/Vaccines/ApprovedProducts/UCM182406.pdf. The CDC has more Q&As here. http://www.cdc.gov/FLU/about/qa/nasalspray.htm
Too much information can sometimes be overwhelming, remember, the nasal spray has been used as a seasonal flu vaccine for years and has been proven to be very safe.
Gregg
Gregg A. Miller says:
In my prior post, "mention" should be "contain"--the nasal vaccine does not contain thimerosal/mercury or other preservatives. Sorry for the poor word choice.
Simon says:
I just wanted to say how happy I am that a reasoned, honest, and accurate source of information about the vaccine is being represented on the internet. There are a lot of scaremongering anti-vaccine ideologues out there, and a lot of irresponsible comment from media doctors, so this was very refreshing.
Martin Lozano says:
My daughter is asthmatic (exercise induced). Her asthma is under control and rarely uses her inhaler. She has no other underlying conditions. That said, she is scheduled to be vaccinated w/ the H1N1 spray. Her pediatric nurse said she should be fine since her asthma is under control. Should I be worried? Or should we bypass the spray and have her injected instead?
V/r,
Martin
kyle says:
another point to make about the 1976 vaccine is how many people would have died from guillian-barre anyway?
Selina says:
I am 4 motnhs pregnant, and I will not be getting the vaccine. For me, the risk of the unkown factors is too high. I have seen nothing that proves the vaccine does not have a negative side affect on the fetus. Consider Thalidomide - a drug given to pregngant women, that was undertested, and caused babies born without arms and legs.
To me, the risk of getting swine flu, not getting treated for it, and dying as a reuslt, is much lower than the risk of getting the vaccine, and finding out that my choice harmed by baby.
Brigitte says:
My 3 year old daughter received the regular flu shot last Thursday. I've been told that they are having an H1N1 flu clinic this upcoming Friday and Saturday in our city. I've heard that they are using the flu mist at the clinic. All this hype about Guillain Barre Syndrome has me worried. I read on one website that parents should wait 2 weeks to a month between receiving the regular flu shot and the H1N1 flu shot. Do you think it's safe to get the season flu shot and H1N1 Flumist so close together? Is there an increased risk of developing this rare disease or any other serious side effect if vaccinated so close together?
el nora says:
I'm 73 yrs old & pretty sure I had the h1n1 flu. It started on 9/25. It was severe the first 3-4 days & symptoms very slowly improved over the following wks. I am basically a health woman but this episode has left me extremely fatigued & feeling at times disoriented (just for a few seconds) I've never had this sensation before. I'm spending every day just laying around with no strength or desire to do anything & it's not normal for me.
I saw my doctor 2 wks ago but going again this week. My husband also was ill & is still feeling a bit tired at times but has recovered. He has a heart condition & is diabetic. Anyone else having long lasting effects after having h1n1 ??
Gregg A. Miller says:
Brigitte,
I'm afraid I can't give specific answers about your daughter, please talk with her health care provider about that. To answer your question in general terms, according to the CDC, the H1N1 nasal spray can be given the same day as the regular flu shot. The H1N1 swine flu shot can be given the same day as the regular flu shot. The CDC recommends against receiving both the H1N1 nasal spray and the regular flu nasal spray on the same day. Hope that helps.
Gregg
Gregg A. Miller says:
Hi Martin,
I'm sorry I can't give you a specific answer for your child, I encourage you and everyone else who has a specific question about your care to sit down and have a face-to-face conversation with your health care provider. You deserve a better answer than I can post on a website. Sorry I can't be of more help.
Gregg
Gregg A. Miller says:
Hi Nora,
I'm glad you're going to see your doctor, and I really hope you feel better soon.
Gregg
Karin says:
Hi Gregg -
I have a few questions. I have a 3 year old and an 8 month old.
My pediatrician's office does not have the H1N1 vaccine and doesn't know when they will get it in, so the only place to go is the health dept. The health dept. doesn't have the injectable without Thimerasol except for kids over 4.
My 3 year old catches everything at school, so I am a bit worried about the nasal live virus version - but I am also concerned about Thimerasol, mercury and autism with the injectable.
For my 3 year old: Nasal with the live virus or injectable with Thimerasol?
The 8 month old has to get the injectable because she isn't old enough for the nasal version. Should I wait to see if my pediatrician gets the vaccines that are Thimerasol free for her? Should I wait for both kids?
I have heard that the first dose primes the immune system and the second dose (1 month later) is the actual preventative - but it doesn't make them immune until 2 weeks after the second dose which is basically a month and half from now!
What to do??? Which is worse - live virus or Thimerasol?
Any input would be greatly appreciated!
Thanks,
Karin
julie m says:
My kids (11 yr.olds) are recovering from, but still have symptoms from a mild virus (cough, slight fever, malaise), and are due to have H1N1 flumist tomorrow. Is it safe for them to receive the Flumist?
Kelly says:
Gregg,
Thanks for all the great information! I am currently trying to make a decision about whether or not to get the H1N1 vaccine, and this information has helped me tremendously.
One question that wasn't addressed:
If you had a severe reaction to the seasonal flu vaccine, will it be likely that you will also have a similar reaction to the H1N1 vaccine since they contain similar ingredients and were made the same way?
Thanks in advance for your time!
Gen Dallaire says:
Hello Gregg:
My pregnant daughter will be taking her 2-1/2 year old to receive the nasal H1N1 spray, and we're wondering if she and her fetus will be placed in harm's way, since the spray contains the live virus. Thanks for your advice!
Gregg A. Miller says:
Hi Karin,
I'm sorry, I can't give you specific advice on what to do with your children, please talk to their doctor about their specific cases. You should know that every good study that has tried to find a link between thimerosal and bad side effects, such as autism, has found no link. You'll definitely find a lot of hype from well-intentioned people on the internet, but inside the medical community, there's no debate about thimerosal. It's considered safe.
Hope that helps,
Gregg
Gregg A. Miller says:
Hi Julie,
This answer is probably too late to help you out, but maybe it will help someone else...usually, the problem with sick people getting the nasal spray vaccine is not that it will make you sicker, but that the nasal spray vaccine won't "take." If you have a lot of nasal congestion, there's a chance the vaccine won't be as effective as it would be if your nose wasn't stuffed up. In general, it's OK to get the nasal spray if you have a mild illness such as a little cough or some diarrhea. The health care provider giving you the vaccine can take a look and decide.
Take care,
Gregg
Gregg A. Miller says:
Hi Kelly,
I can't comment on your particular case, and I don't know all the details about your bad reaction. In general, it is possible that if someone had a bad allergic reaction to a previous flu vaccine, they will have another bad allergic reaction to this year's flu vaccine or the H1N1 vaccine. This could be because they are allergic to some component in the vaccine--eggs, gentamicin, etc. You should talk to your doctor about what type of reaction you had to the previous vaccine, and whether you should take future vaccines.
Hope that helps,
Gregg