Your questions about H1N1 flu
November 19, 2009
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Have a question about the H1N1 pandemic? Use the comments section of this article to send us your query and we'll answer a selection.
The questions below are answered by Dr. Paul Philbrook, chief, department of family medicine, The Credit Valley Hospital, Mississauga, Ontario.
Q: 1 half-dose enough for a 10 yr old shy a week?
My son just got his 1 half-dose today. He is 9, but turns 10 in 5 days. I was told by the nurse that he won't need a second half-dose. However, if he was 10 on the day of his shot, he would have gotten a full dose. Please clarify this - will he still be protected?
Ongoing clinical trials in Europe have recently demonstrated that a second half dose of the H1N1 vaccine for healthy children aged 3 to 9 years is not necessary. One shot is considered enough to provide protection. About your son's age, you needn't worry. There is sufficient protection from this shot to provide for someone who is about to turn 10, even without taking into account variation in body size and physical maturity. I hope he has a happy birthday!
Q: 2 Yr old Received 1/2 Then was Exposed
My 2 year old daughter received her first 1/2 dose of H1N1 vaccine on November 5, 2009. She had also just finished a 10 day course of antibiotics for strep throat. On November 10, 2 children at her daycare tested positive for H1N1 and have not been back since. There are only her and 1 other child in the daycare. If they were going to contract the virus. How long would it take after exposure? As well, would she have some immunity already? To date (fingers crossed) she has shown no symptoms at all. Nor has the other child. Thank you!
Precise information about the characteristics of the H1N1 infection are still not clear. However, based on current information, and the known characteristics of similar influenza infections, the children who became sick at her daycare were likely contagious for about one day before they became sick. After being sick, they could have given the virus to others until their fever resolved. But this is not reliable, because some people are not feverish.
After exposure, your daughter could incubate the virus before getting sick for one to seven days, but about one to four days will be typical.
Early data from a Spanish study seems to suggest that 100 per cent of children aged six months to three years will be immune after 21 days. So your little one would have been exposed to H1N1 only a few days after she had her shot. You can hope that during the incubation period she is developing some immunity from the shot, and that, if she gets sick, it will be milder than if she didn't get the shot. Her protection will not be very high yet.
Q: Question about nasal spray H1N1
What happen if you sneeze after 30 minutes of H1N1 nasal spray vaccination? Can you provide us a general guidline(s) do's and don't s after nasal vaccination so we will maximize the objective of getting the vaccination the first place?
I have had no first hand experience with this vaccine. This is a rather different form of the vaccine. It is a live, attenuated (weakened) virus, and it is only intended for people between two and 49 years of age, with no serious chronic conditions. For detailed information about this vaccine, I suggest you go to http://www.cdc.gov/vaccines/pubs/vis/downloads/vis-laiv-h1n1.pdf?
The questions below are answered by Dr. Paul Philbrook, chief, department of family medicine, The Credit Valley Hospital
Q: What are the chronic conditions referred to? My adult daughter has Downs Syndrome and has had heart surgery. Does that qualify as a 'chronic condition'? People with Downs Syndrome have different immune systems. I can’t get through to her doctor’s office.
The chronic conditions are: asthma, other chronic lung disorders, cardiac disorders, renal, diabetes, cancer, immunosuppression (on chemotherapy, corticosteroids, kidney transplant), immunodeficiency (HIV), anemia, morbid obesity (BMI over 40), neurologic, neuromuscular and dementia. Without knowing more about this individual it is difficult to know if she is high risk or not. I would err on the side of caution and advise that she be administered the vaccine.
Q: Having polio as a child,I have been told that I do not require the H1N1 vaccine. I have tried to do some research and nothing seems to answer my question. Could you please let me know if this is true?
I think this question relates to the above first question, but in a backwards way: People with previous neuromuscular conditions may be considered at high risk, if this increases the chance that they may aspirate. Thus they should get the vaccine. But most post-polio people are not at increased risk of aspiration, so their risk is really the same as the average person.
Q: On a scale of 1-100, where does H1N1 rate in terms of chance of infection if exposed, and consequences of infection? If Ebola rates a 100 (extremely contagious, and if you get it you die), Smallpox rates maybe an 80 or 90. Where does H1N1 sit?
Currently, the morbidity and mortality of H1N1 influenza is similar to that of seasonal flu. Most healthy people will have a mild viral illness due to H1N1 that will be a nuisance, but not serious.
Q:Also why does this vaccine still use Thimerosol as a preservative when it was banned from vaccines in the US 20 years ago?
In fact, Thimerosol continues to be used in other vaccines, including the seasonal flu vaccine. Thimerosol is considered to be safe and harmless.
Q: What are the ingredients in the H1N1 vaccine?
The ingredients of the adjuvant H1N1 vaccine include the antigen and the adjuvant. The antigen component is the split influenza virus, inactivated, containing antigen equivalent to A/California/7/2009 (H1N1)v-like strain (X-179A). This is derived from virus propagated in eggs. The preservative Thimerosol is also present in this component.
The adjuvant component contains tocopheral (Vitamin E), squalene oil (a cell membrane component) and polysorbate (an emulsifier).
The questions below are answered by Dr. Lorne Small, Infectious Diseases Specialist, The Credit Valley Hospital
Q: Our daughters have both been sick with a flu for the past four days. They had headaches, body aches, nausea and diarrhea. They did not have a fever. Before we have them vaccinated, I would like to know whether they have already had the H1N1 virus. If so, there is no need for them to be vaccinated. How do we get them tested to see if they have had H1N1?
It sounds as though the children have had one of any number of viral illnesses, which are common this time of year. If they predominantly had gastrointestinal symptoms, it was likely a gastrointestinal virus and not H1N1 influenza or any other influenza virus. Influenza illness is predominately respiratory and the term "flu" related to gastrointestinal infection is somewhat of a misnomer as these are generally distinct viruses. That being said, influenza, H1N1 or otherwise, is sometimes accompanied by gastrointestinal symptoms, however usually some respiratory symptoms, such as a cough, will be present.
To answer the question specifically, it is unlikely that you will be able to get them tested as testing is currently not recommended for the general population and is reserved for severe cases or for those who have other illnesses. So the short answer is you will probably not be able to know for sure whether they had it or not. If you intended to have them vaccinated before, you should not change your plans based on their recent illness.
Q: If you have a cough or cold (no fever present), can you still get the H1N1 shot?
You can get vaccinated, but you are best off to wait a few days for your illness to improve somewhat. For those who do have fever, they should at least wait until the fever resolves. There is no harm in getting vaccinated while ill, but there is a theoretical possibility that the vaccine won't work, because your immune system is busy dealing with the present infection.
Q: I thought people with immune-compromised systems mounted a less intensive response to the virus and that it was only people with good systems who got really sick? What is going on here?
It is true that our symptoms during an infection are largely caused by our immune system's attempts to fight the infection.
Those who are mildly or moderately immunocompromised will have a higher chance of becoming infected, will likely still mount a sufficient immune response to make them sick and will have a more difficult time clearing the infection. Hence they are prioritized for vaccination.
Those who are severely immunocompromised often do not have the intense immune response that healthy people do, but that doesn't mean they don't get sick. Infections in severely immunocompromised individuals are extremely dangerous. Since they don't mount a normal immune response, their presentation of the illness is often atypical. Once they have symptoms of infection they deteriorate quite rapidly as the infectious organism spreads easily and unchecked throughout the body. So they do need to be urgently vaccinated.
Q: Is the non-adjuvanated vaccine going to be available for people with autoimmune disorders?
This question likely relates to the concern of a vaccination triggering a flare of an autoimmune disorder. The adjuvant is intended to make the vaccine more susceptible to an immune response and thus have a better chance of providing immunity. Theoretically, if the adjuvant helps create a better immune response it might also have more of a chance of worsening an autoimmune disease.
As of now, the non-adjuvant vaccine has only just become available and is specifically intended for pregnant woman and possibly very young children. The use of adjuvant versus non-adjuvant vaccine will likely not affect the status of an autoimmune disease, however autoimmune diseases vary greatly in both, type and severity, and may fluctuate between flare-ups and remissions. If there is concern regarding any vaccination and its effect on an autoimmune disease, it should be discussed with your family physician or rheumatologist who will be familiar with your specific autoimmune condition and its status.
The questions below were answered by Dr. James Downey, infection control officer at Toronto East General Hospital.
Q: My daughter in law is nursing her 2-month-old baby and has a 2-year-old as well. Her Dr. has advised her and her 2-year-old to take the non-adjuvent vaccine. Do all Toronto clinics have it available now and will they give it to her if she asks?
A: I disagree with the FDR recommendation. All children over 6-months are safe to have the adjuvanted vaccine and so are nursing moms. The non- adjuvant vaccine has not yet been made available to anyone and when it is pregnant women will get first access. When it becomes available, it may be that there won't be enough available to do persons who don't really have to have it.
Q: We are seniors and flying to India, Thailand, Singapore and returning Feb. 2010. Can we get H1N1 shot before leaving for our trip on November 15 ? There are lot of cases with this flue in these countries and we can't get shot there.
A: At present, any person with high risk for medical reasons can get the vaccine. Anybody who is not high risk is being asked to wait due to limited vaccine availability. Seniors are not necessarily placed in the high risk group just because they are seniors.
Q: Is the H1N1 vaccine required for people who have had swine flu?
A: Persons who had the "swine" flu in the first wave should get the vaccine, as it will boost their immunity. Remember that the virus changes itself day-to-day and week-to-week (mutates) and so the strain that infected the person during the first wave might be different from the virus strain circulating now. Persons who have had documented "swine flu" in this second wave may not gain a lot of benefit from the vaccine now but see the next answer below.
Q:What's the effect of H1N1 vaccine to people who already had swine flu?
A:The value of the vaccine to persons who have already had the swine flu is to boost their immunity to the virus that is circulating now. Thus such a person would have high level immunity and be considerably less likely to get the flu again (in the near future) and even if they did, they would be less likely to spread it to others. This is the real value in getting the vaccine even if the person could have already had the flu
Q: If my child is sick, do I go straight to my doctor and ask for a prescription, or only if he's already quite sick? Or, do I wait and see how the symptoms progress, and only seek attention if they do get worse, by which time it's too late for Tamiflu?
A: Since most persons (even children) get mild illness from the pH1N1, the best strategy is to wait and watch the child and seek medical attention only if the child is quite sick. The value of Tamiflu in mild illness is controversial and unlimited use of Tami flu will accelerate the development of resistance, thus making Tamiflu of no value for treatment of pH1N1 (in anybody)
Q: I'm 48 years old, and have a compromised immune system (Rheumatoid Arthritis, Chronic Fatigue Syndrome, EBV lingering after a bad infection in 2008, and more). Am I supposed to be in the priority group or to wait for the vaccine? What is the waiting time between the ordinary flu shot and the H1N1 shot?
A: Persons with chronic rheumatologic disease are understood to have immune systems that are not completely normal. This would put such a person in the high-risk category and qualify them for vaccination now. The other two conditions listed are not known to place the person at high risk.
There have been several recommendations concerning the waiting time between vaccinations. The most up to date information that I am aware of is from Health Canada and states that both vaccines can be given at once. My opinion is that this would be correct based on what is known about the human immune response to vaccination.
PREVIOUS QUESTIONS
Q. If you are over 65 and already received the regular seasonal flu shot, how soon can you receive the H1N1 shot (assuming you are on the priority list)?
A. You can receive the H1N1 shot now if you are in a priority group. If you are over 65, it would mean you are a priority if, for instance, you live in a remote community or if you live or care for a vulnerable person or infant younger than 6 months old.
Q. What about snowbirds going south for the winter? Can we get our shots before we go?
A. If you are not in a priority group, you will have to wait for the general vaccination clinics, but check with your family doctor before you go.
Q. Are parents of children under 5 considered a priority? If so, does the entire family need to be vaccinated at the same time, or can the parents go separately?
A. Unless you are caring for a child younger than 6 months old, parents will have to wait and go separately once the priority groups have been vaccinated.
Q. Why has Canada gone with the adjuvant vaccine?
The WHO recommended countries use dose-sparing vaccines whenever possible. By developing an adjuvanted vaccine, less of the virus material (antigen) is used, enabling more people to be vaccinated more quickly. A small supply of unadjuvanted vaccine had been ordered for some pregnant women and it starts rolling out this week.