H1N1 Update: CDC Offers Reassurance on Vaccine Safety and Availability

H1N1 Update: CDC Offers Reassurance on Vaccine Safety and Availability

The CDC addressed fears over 2009 H1N1 vaccine safety and availability at a press briefing Tuesday.

CDC Director Thomas Frieden addressed "three major concerns that people have" — that 2009 H1N1 is "just a mild illness"; that the vaccine may not be safe; and that it's already too late to be vaccinated.

Dr. Frieden countered with a reminder that 2009 H1N1 has killed many people and will likely kill more. Regarding safety, he said that the vaccine is made in the same way and in the same facilities as seasonal vaccines, which have an excellent safety record. And as to the futility of vaccination, he said, we "don't know what the rest of this long flu season is going to hold. We haven't had a flu season like this in at least 50 years."

He added: "We're very confident that there will be plenty of vaccine for everyone who wants to be vaccinated. It won't be available when everyone wants to be vaccinated."

US CDC Weekly 2009 H1N1 Flu Media Briefing

October 06, 2009, 12:00 p.m.

• Audio recording (MP3)

Operator: Welcome and thank you for all standing by.  I would like to remind parties your line is in a listen-only mode until the question and answer mode.  Today's call is being recorded.  If you have any objections you may disconnect at this time.  I'll turn it over to Glen Nowak.

Operator: Thank you for dialing in.  Today's update will be conducted the director of the Centers for Disease Control and Prevention.  Thank you. 

Thomas Frieden: Thanks, Glen.  Thanks for being here.  What  I would like to do is update you where with are with the virus and what we're beginning to see in terms of both of them.  Also to discuss some of the concerns that we have been hearing out in the field about the vaccine in particular.  As of today, influenza is widespread in most of the United States.  We're seeing it continuing to increase in some areas.  We're seeing a slight decrease in some areas.  We note that it's now present throughout the united states.

It's still remains overwhelming H1N1 pandemic influenza and influenza is a tough enemy.  It's unpredictable.  Although there has been a slight decrease nationally and in some areas, in other areas it's still on the upswing.  We wish we could predict the future.  But we can't.  We do know that flu season generally lasts well into may.  So, we've got many, many months ahead of us where we don't know what will happen and we need to take the best steps we can to protect ourselves.

Vaccine efforts are starting.  All states in the U.S. have ordered vaccine.  It's being delivered and each Friday, we'll provide information on the amount of vaccine available to each state and the amount of vaccine each state has ordered.  That's a little complicated, because what we have decided to do is make vaccine available as soon as it comes off the production line.  That means, it's coming available in lots and states learn each day, of additional vaccine available to them.  It's a little bit of a messy process and we expect it to be somewhat bumpy in the first few weeks. 

This is the best way to get the vaccine out and available as soon as it becomes available. This week, the flu vaccine became available in the internasal variety.  Next week, it will become available in the injectable variety.  The first was done yesterday with a priority on health care workers and children as well as people who care for infants. 

Flu mist, only able to be used for people age 2 to 49 and who do not have an underlying health problem.  With the production of this strain, we have cut no corners.  This flu vaccine is made as flu vaccine is made each year.  By the same companies.  In the same production facilities.  With the same procedures.  With the same safety, safeguards. 

We have had literally hundreds of millions of people vaccinated against flu with flu vaccine made in this way.  That enables us to have a high degree of confidence in the safety of the vaccine. It has an excellent safety record.  We wished we had the vaccine earlier.  It would have been great to have had it back in April or May.  But the current science doesn't allow us to produce in much less than six months, and that's what it has taken to produce it at this time. 

People have concerns about vaccination.  People always have concerns about vaccinations and that's understandable.  We would rather not take any shots or medicine and stay healthy. 

The flu vaccination, being tried and true, is very effective.  What we're seeing still is an excellent match between the virus that's spreading throughout the U.S. And the strain that was chosen to make the vaccine against.  So, we expect a very good match a very good degree of efficacy of the vaccine.  It will work to protect you if you get in time. 

Three major concerns that people have, despite the clear message from all of us in public health and doctors throughout the health care field that vaccine is our best tool to protect against the flu. 

Vaccine is the best tool to protect the flu, because, not only does it prevent people from becoming severely ill, it also prevents the spread of flu. 

The first concern that we hear is, oh, flu is just a mild illness.  Actually, on average, flu is not a mild illness.  It can make you pretty sick, knock you out for a day or two or three.  Make you miss school and work.  And for too many people end up sending them to the hospital, to the intensive care unit and tragically some people may die from it.  In fact, this year already, we have seen quite a few children who have died from flu.  So, although it is not a disease that will send lots of people who get it to the hospital, it can be very serious and even for those for whom it's an average case, it's no picnic.  You would rather avoid it for yourself and your kids.  The best way to do that is with vaccine. 

The second concern is that the vaccine may not be safe.  Corners may be cut.  Short cuts may have taken.  It's a new or different vaccine.  In fact, none of that is the case.  The vaccine is made in the same way it's made each year.  Each year, we look at the strains that are circulating and we look at the ones that likely to be in the population.  We put those into the flu vaccine.  That's exactly what has been done in this case.  Specifically against H1N1 influenza.  Made in the same production facilities with the same companies with the same methods.  As it is made each year.  Hundreds of millions of doses have been given.  My children will get it.  Other public health and societal leaders and experts will get it.  It's something that we have a high degree of confidence in. 

Third concern, it is too late for the vaccine, well, it's too soon to say it's too late.  We don't know what the rest of the season will bring.  Even in places where flu has been widespread.  It's affected 5% to 10%.  That leads 90% to 95% of the population that's still susceptible.  We can't predict what the future will hold and we know that vaccination is our best tool to reduce the impact of flu.  Where we stand now, all states have placed orders.  More than 2 million doses have been ordered.  Nearly all of the doses that are available.  More doses are becoming available each day.  When the states learn that vaccines become available, they place an order, it orders it by the provider.  So, the states at each state level, they identify a certain number of people who will receive or facilities which will receive the vaccine and how many doses will receive.

The state allocates it out to different providers to receive vaccine.  The flu mist or the shots.  The shots can come in single dose vials or multiple dose vials.  All of that has to be factored in when ordering.  It's shipped from four different warehouses.  Temperature-controlled.  It stays at the same temperature until it gets to the place where it will be given.  If it's the shot, its together, about the same time as needles, syringes.

It's a very big and complex undertaking.  It will be different in different parts of the country.  Some parts of the country will do lots of school-located vaccination.  Some places won't do so much. Some places may be better prepared than others.  Our goal is to help as many places as possible to prepare as well as possible.  So they can start as soon as possible.  And with that, I'll stop and take questions.  We'll start with the room.  Any questions here? 

Reporter: Hello, I'm Rebecca from CBS Atlanta.  There's seem to be some confusion in the some of the states and local governments.  As to how to disperse the vaccine, given such a small amount in this initial distribution, have you been given guidance to how to distribute the vaccine? 

Thomas Frieden: These are early days for vaccination.  We have only a small number of doses available.  The injectable med vaccine will become available next week.  And, initially, for the flu mist, the groups that are best to vaccinate with that, are young, healthy people, like health care workers, as well as people who care for infants, as well as school children.  It's really up to the state to figure out what will work best.  There is not a prioritization within the priority groups.  All of those groups are priority.  When the shot's gone, we want the five key priority groups to be vaccinated.  Pregnant women, health care workers, people who care for infants under the age of 6 and school children and young adults up to the age of 24 years. 

Reporter: One of the questions we have gotten from some of our listeners at NPR. If there's a problem with the vaccine how long before you knew it and how long they would know it?

Thomas Frieden: There have been initial studies from the clinical trials that have shown, nothing to be particularly concerned about in the trials that have been public so far.  We look at that very carefully.  We have a number of different systems in place.  Using a variety of sources including health plans and others.

The vaccine problems that could occur, would likely occur at a very low rate.  1 per 100,000.  It would take some time to know there was a problem.  On the other hand, there's no reason to think there would be more problem with this vaccine than with the vaccine each year.  We expect that there will be concerns for problems.

For example, we know that many people, each week, develop health problems, either it's a miscarriage, or a heart attack, even tragically a sudden death, and that those problems will not be prevented by the flu vaccine.

Some people who get the flu vaccine will experience some bad outcome and we will look at each report to see if it's related and if, in the overall group, there's any sign of an increase rate of adverse events.  We'll share that information publicly.  We're committed to transparency.  We'll go to the phone for the first call. 

Operator: Thank you.  At this time if you would like to ask a question, please press star 1. 

Betsy McKay: My question was about distribution.  I wondered if states are learning each week how much they can order for the next week, or do they get an advanced notice of how much they'll be able to order.  Is advance ordering something you're able to let them do, given the production schedule? 

Thomas Friden: We have the anticipated schedule for the next few months.  Obviously, the further out it gets, less certainty we have.  At least for the next few weeks, we have a pretty high degree of certainty that the vaccine will be available as per what the manufacture has told us and we're hoping and advising states that they should be actively planning for vaccination programs and anticipating that that the vaccine will be available.  By substantial quantity by the middle of November. 

Mike Stobbe: Thank you. Mike Stobbe from the AP.  Doctor, can you give us an updated number about how many doses will be available this week?  Also, is demand outstripping supply.  Is supply outstripping demand at this point? 

Thomas Frieden: This week, as of yesterday, about 2.4 million doses were available for ordering. About 2.2 million of them had been drawn down or ordered by this week.  Each day, as more vaccine is clear, more vaccine becomes available for ordering, each Friday we'll provide the totals. Some which would have become available that Thursday or Friday.  We're trying to make sure that we cut as much time as possible off the cycles to get it out and available for providers to vaccinate. To do that, means a little bit of messiness on how it comes out.  If there's a minor problem with any of the vaccine in any of the warehouses, we don't have it available for ordering. We have to make sure it's safe and temperature-controlled.  Before it will be released to the states.  Some lack of certainty.

We have a high degree of confidence by middle October, we'll have substantial amounts of flu vaccine available.  Clearly at this point, only some vaccine and not everyone can receive that vaccine.  Demand is outstripping supply. We expect that fairly soon, supply may well outstrip demand.  The challenge will be to try to ensure the people who benefited the most have every opportunity to be vaccinated. On the phone? 

Operator: Our next question is from "Time" magazine.

Alice Park: A question about the supply issue.  Looking ahead, did the calculations that the CDC made as far as the ordering include the potential that more and more individual entities would mandate the vaccine for their health care workers.  In New York, mandated it for the entire state that right now, we're having problems with getting the seasonal vaccine in enough supply?  More entities demanding the vaccine, therefore a higher rate of compliance or demand for the vaccine than you have had in previous seasons? 

Thomas Frieden: We're very confident that there will be plenty of vaccine for everyone who wants to be vaccinated. It won't be available when everyone wants to be vaccinated.  Providers will receive it from directly from the manufacturer.  Information should be available to the public through the state health department, to find out the details of where it will be available. That's not ready quite yet. Because, there are not large quantity -- there is not a large quantity of vaccine available today.  Out there to be given H1N1.  Seasonal flu vaccine, some areas have had less.  They're well over 50 million doses distributed earlier.  We're particularly Prioritizing those key groups I spoke about earlier.  On the phone? 

Operator: Next is from CNN.  Your line is open.

Karen Denice: Thank you for taking my question, are you seeing any mutation in the virus at this point and are you concerned at some point, that the vaccine will not match the virus as we continue through the season and we get seasonal flu and H1N1 both out there? 

Thomas Frieden: Our biggest concern is that the virus could change, mutate to become more deadly.  We have seen nothing that would be the case.  So far, in fact, the virus has been quite stable genetically. It hasn't changed much at all. The part of the virus that determines whether or not it's very deadly is a different part of the virus that determines whether or not you're going to be protected by the vaccine.  That's good news.

Because, it means that the vaccine that we have now, which is very effective, very highly, tightly matched with the virus that's spreading is likely to protect you even if this virus were to become more deadly.  And the match is excellent right now of the more than 1,000 samples that have been looked at from around the world. The vaccine strain is right in the middle.

Of that genetic variability and the variability is very small. We expect there will be a high level of match and a high level of effectiveness for this particular vaccine against this particular virus.  Clearly the most concerning possibility is the pocket that it could mutate.  Right now, neither of those things have happened. On the phone?  Another from the phone? 

Operator: Robert Bazell from NBC News, your line is open.

Robert Bazell: The local state health departments have had the cancel seasonal vaccine influenza programs because of, they haven't gotten orders when they wanted to, and San Francisco and some other places have had to cancel novel vaccine programs that they had, because it becomes clear even though they placed an order, promised an order on a certain date, the vaccine ends up not coming. Can we expect that a lot in the weeks and months ahead.

Thomas Frieden: As we anticipated the first couple of weeks are going to be bumpy. There are problems identified or not identified with some of the initial shipments.  But, I think what we're seeing now, is the tap beginning to flow.  We're seeing substantial quantity of vaccine beginning to get out. In an average flu season, we get out about 25 million flu doses out.  By the middle of this month, we're going to have tens of millions of doses available. Although it won't be everywhere, it will be widely available in the next few weeks.  We'll be comfortable as the season goes on. From the room? 

Reporter: Thank you. What would you say to people who are not in the priority group who are very eager and might become frustrated if they don't get vaccine soon, what your advice be for them? 

Thomas Frieden: People who are healthy, age 25 to 49 who can get flu mist.  Not one of the priority groups. There's vaccine available. It will be a while before vaccine is widely available.  We wished it was available for everyone now. Technology doesn't enable that to happen. Perhaps in a few years, we'll have new technologies which will allow that to happen.  That doesn't help us for this year.

Simple things that you can do to protect yourself against the flu, stay home if you're sick.  Very important. Cover your mouth when you cough and sneeze.  And wash your hands often.  Those three simple things can make a really big difference. On the phone? 

Operator: The next call is from the Associated Press.

Lauren Neergard: Kind of a technical question ensuring that children under 10 get their doses.  What advice are you giving to some of these providers to make sure they actually have enough on hand to give the kids a second dose, are you telling them to plan ahead and partial out that much and keep it on hand for the three-week return visit? 

Thomas Frieden: We anticipate that children age 9 and below will need two doses.  We don't have the final data on that.  We ask that places don't hold vaccine back.  More will be coming.  Vaccinate as many people as you can.  That second dose, given three to four weeks after the first dose, there will be plenty more to provide then.  On the phone? 

Jon Cohen: Hi, thanks.  You said you had an anticipated schedule, can you tell us what it is or make it public. You said that right now, supply isn't meeting demand.  Yet, that conflicted with requests for the 2.4 million doses, only being 2.2 million

Thomas Frieden: We can provide information and we will each Friday.  It's information that changes day-to-day as manufacturers figure out how much is ready for shipping and to clarify, vaccine goes from the manufacturers to a central distributor, and from the central distributor, onward to providers or the health departments to actually vaccinate.  I'm sorry, the second part of your question was about?

Supply and demand.  The 2.4 million available was the first 2.4 million doses.  Some states were figuring out exactly where they wanted to spend or send those doses.  So far nearly all of that 2.2 million has been called down.  It will take some time to get the whole system from the manufacturer through the distributor, to the providers and to people who want to get vaccinated up and running.  One of the things that this weekend and next, will provide a dry run.  Not enough vaccine around.  Although we wished we had more, some can get vaccinated.  It will get us ready to get a running start on vaccination mid to late October. 

Reporter: Thanks. 

Reporter: Doctor, you mentioned once or twice the possibility in such a situation that a problem was identified in the shipments, I guess at the production facility, has that happened yet?  Problems identified with swine flu vaccine.

Thomas Frieden: No vaccine has been found to problematic in any way.  Each time we do vaccination programs, we're meticulous at tracking and tracing each of the lots of vaccine.  That is particularly important not just to ensure that's safe, if there's a problem either with safety or with not work, to know that there was any point in the chain, the chain was compromised.  It's just a question of verifying that things are working well.  We haven't had any vaccine so far rejected because of any problem.  Two more questions.  On the phone. 

Todd Neal: I have a couple of nonvaccine questions.  I wonder how hospital and emergency departments are faring throughout this outbreak?  Also, is CDC making any recommendations about restricting visitation to patients suspected or confirmed H1N1. 

Thomas Frieden: With we have seen, are real stresses particularly on the emergency departments.  Largely from people who are coming in because they're very worried about influenza, may have influenza, probably don't need to be in a hospital emergency department.  On the other hand if you have an underlying health condition, if you're pregnant, it's very important when you have the flu to get treated promptly.

It's a complicated message and getting that understood and acted on effectively in communities throughout the U.S. is very challenging.  We see some stresses on emergency departments.  We have not so far seen problems with intensive care units with people who need respiratory support.  That's something that we're tracking closely.  That would be a great concern.

One of the things that hospitals can do to reduce the risk is to limit the number of visitors.  That's a balance between the emotional well being and the recovery of the patient.  We can provide general information for health care facilities about.  It's a facility by facility decision at this point.  One more question on the phone.

Robert Lowes: Yes, doctor, I have two questions, one is, there are recommendations to have patients who are, who have underlining conditions, any concern in your agency there may not be enough pneumonia.

Thomas Frieden: It's underused.  If you get the flu, it protects you against one of the more serious complications of the flu.  We haven't seen a shortage of pneumonia vaccine.  You had a second question. 

Robert Lowes: Yes, there's one poll which, by Harvard Public School of Health, that showed that only about 50% of American adults plan to get vaccinated and only about 40% were absolutely certain they were, are you going to do anything special to respond to that, I guess, lack of motivation to get vaccinated, any special or outreach plan? 

Thomas Frieden: There have been several different polls.  Most of them find that most people want to and plan to get vaccinated.  What will happen will depend on a lot of things.  How easy it is to get vaccinated.

And addressing the three concerns that I talked about earlier, understanding that flu isn't always mild, it can kill you, understanding that this vaccine is made in the same way that the seasonal flu vaccine is made, hundreds of millions of doses with an excellent safety record, and understanding even though the flu may be here in your community and may be decreasing in your community, it's a great idea to get vaccinated because you don't know what the rest of this long flu season is going to hold.

We haven't had a flu season like this in at least 50 years.  Unless there are any questions from the room, I think -- thank you very much for your interest.  It's a real challenge to balance for the public, information about the vaccine, information about the virus, understanding whether it's in the cases of emergency departments, they need to get care promptly on one hand if you're really sick or have an underlying health condition.

And similarly with vaccine, to ups that people do have concerns about safety and about whether it's necessary.  In fact, the flu vaccine is our best weapon against the flu.  We're fortunate to have the vaccine here.  Would have been great to have it earlier.  It's starting to become available.  Thank you very much. 
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U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

Revised US CDC Recommendations for Use of Antiviral Drugs

Revised US CDC Recommendations for the Use of Influenza Antiviral Drugs

September 8, 2009 2:00 PM ET

Background

On September 8, 2009 CDC updated its recommendations for the use of influenza antiviral medicines to provide additional guidance for clinicians in prescribing antiviral medicines for treatment and prevention (chemoprophylaxis) of influenza during the upcoming 2009-2010 flu season.

These recommendations are intended to help clinicians prioritize use of antiviral drugs for treatment and prevention of influenza. In general, the priority for the use of antiviral medications this season continues to be in persons at increased risk of influenza-related complications as outlined in the antiviral recommendations posted on May 6, 2009.

How is the new guidance different from the guidance that was issued on May 6, 2009?

The priority use for antiviral medications during the upcoming influenza season remains the same as outlined in the antiviral recommendations posted on May 6, 2009; that is to prioritize use of these drugs for those patients who are severely ill (hospitalized) and those patients who are ill with influenza-like illness and who are at high risk for influenza related complications.

The updated guidance provides additional context and guidance for clinicians in an effort to ensure that antiviral drugs are prescribed appropriately this season and that they reach those in greatest need quickly. This includes actions that clinicians may consider taking to reduce possible delays between illness onset in high risk patients and treatment, including a suggestion that clinicians consider providing prescriptions for antiviral medications ahead of time for such patients.

In addition, the updated guidance provides more information about the appropriate (and limited) situations in which antiviral medications should be used for chemoprophylaxis (prevention) this season. The updated guidance states that antiviral drugs should not be used for prevention in healthy persons based on community exposures.

In addition, the guidance places an emphasis on the use of antiviral drugs for early treatment (versus preventatively). The updated recommendations seek a balance between providing clinicians the information and guidance needed to reach those at greatest risk with appropriate and timely treatment; to reduce the chances of antiviral-resistance through inappropriate or unnecessary chemoprophylaxis; and yet to still recognize the overarching importance of clinical judgment in making treatment and chemoprophylaxis decisions.

What are influenza antiviral drugs?

Influenza antiviral drugs are prescription drugs (pills, liquid, or inhaler) that decrease the ability of flu viruses to reproduce. While getting a flu vaccine each year is the first and most important step in protecting against flu, antiviral drugs are a second line of defense in the prevention and treatment of flu.

Who is prioritized for treatment with influenza antiviral drugs?

Most people ill with influenza will recover without complications. 
Some people are at increased risk of influenza complications and are prioritized for treatment with influenza antiviral drugs this season. They include:

• People hospitalized with suspected or confirmed influenza
• People with suspected or confirmed influenza who are at higher risk for complications
• Children younger than 5 years old (children under 2 years old are at higher risk for complications than older children)
• Adults 65 years and older
• Pregnant women
• People with certain chronic medical or immunosuppressive conditions
• People younger than 19 years of age who are receiving long-term aspirin therapy

Physicians may also decide not to treat some people in these groups and/or treat people who are not in these groups based on their clinical judgment.

Who is lower priority for treatment with influenza antiviral drugs?

Treatment with influenza antiviral drugs is generally not needed for people who are not at higher risk for complications or do not have severe influenza, such as those requiring hospitalization. However, any suspected influenza patient who presents with emergency warning signs (for example, difficulty breathing or shortness of breath) or signs of lower respiratory tract illness should promptly receive antiviral therapy.

Doctors may treat some people who are not in a high risk group based on their clinical judgment. In addition, doctors also may decide that treatment is not needed for some who are in a high risk group based on their clinical judgment.

Which influenza antiviral drugs should be used for treatment this season?

At this time, treatment with oseltamivir (trade name Tamiflu®) or zanamivir (trade name Relenza®) is recommended for all people with suspected or confirmed influenza who require hospitalization.

What are the treatment benefits of influenza antiviral drugs?

For treatment, antiviral drugs should be started within 2 days after becoming sick. When used this way, these drugs can reduce the severity of flu symptoms and shorten the time you are sick by 1 or 2 days. They may also prevent serious flu complications.

Antiviral drugs may be especially important for people who are very sick (hospitalized) or people who are sick with the flu and who are at increased risk of serious flu complications, such as pregnant women, young children and those with chronic health conditions.

How effective are antiviral drugs at preventing the flu?

When used to prevent the flu, antiviral drugs are about 70% to 90% effective against susceptible viruses (i.e., viruses that are not resistant to the antiviral medication). It’s important to remember that flu antiviral drugs are not a substitute for getting a flu vaccine.

When should health care providers start treatment with antiviral drugs? 

Once the decision to administer antiviral treatment is made, treatment with zanamivir or oseltamivir should be initiated as soon as possible after the onset of symptoms. Evidence for benefits from antiviral treatment in studies of seasonal influenza is strongest when treatment is started within 48 hours of illness onset.

However, some studies of oseltamivir treatment of hospitalized patients with seasonal influenza have indicated benefit, including reductions in mortality or duration of hospitalization even for patients whose treatment was started more than 48 hours after illness onset.

When treatment is indicated, health care providers generally should not wait for laboratory confirmation of influenza to begin treatment with antiviral drugs because laboratory testing can delay treatment and because a negative rapid test for influenza does not rule out influenza. The sensitivity of rapid influenza diagnostic tests can range from 10-70% for 2009 H1N1 virus.

What can health care providers do to reduce delays in antiviral treatment?

Clinicians can take several actions to reduce delays in antiviral treatment initiation. These include:

1. Informing people at higher risk for influenza complications of the signs and symptoms of influenza and the need for them to get treated early.
2. Ensuring quick access to telephone consultation and clinical evaluation for these patients as well as patients who report severe illness.
3. Considering empiric treatment of patients at higher risk for influenza complications based on telephone contact if hospitalization is not indicated and if this will substantially reduce delay before treatment is initiated.

What are the symptoms of seasonal influenza or 2009 H1N1 influenza?

The symptoms of seasonal and 2009 H1N1 influenza include fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills and fatigue. Some people may also have vomiting and diarrhea. Some people may be infected with the flu, including 2009 H1N1, and have respiratory symptoms without a fever.

Who is at higher risk of influenza related complications?

Groups at higher risk for influenza related complications are similar to those at higher risk for seasonal influenza complications and include: children younger than 5 years old; adults 65 years of age and older, pregnant women, people of any age with certain chronic medical conditions (for example, asthma, diabetes, lung disease, people with weakened immune systems, etc.) and people younger than 19 years of age who are receiving long-term aspirin therapy.

For children younger than 5 years of age, note that the risk for severe complications from seasonal influenza is highest among children younger than 2 years old.

What actions should health care providers take when waiting for influenza test results?

When treatment is indicated, health care providers should consider empiric treatment while influenza test results are pending, if the clinicians decided to test, especially if there will be a significant delay before testing can be performed. Once the decision to administer antiviral treatment is made, treatment with oseltamivir or zanamivir should be initiated as soon as possible after the onset of symptoms.

How long should patients receive treatment with antiviral drugs?

The recommended duration of treatment is five days. However, hospitalized patients with severe infections might require longer treatment courses.

When should clinicians prescribe antiviral drugs for prevention of influenza?

Pre-exposure antiviral chemoprophylaxis should only be used in limited circumstances, and in consultation with local medical or public health authorities. Certain people at ongoing occupational risk for exposure (health care personnel, public health workers, or first responders who are working in communities with influenza A H1N1 outbreak), especially those at higher risk for complications of influenza, should carefully follow guidelines for appropriate personal protective equipment to prevent influenza exposure to influenza. Health care workers at high risk of influenza-related complications who cannot minimize exposure may consider temporary reassignment.

Who should receive antiviral drugs for prevention of influenza?

Antiviral chemoprophylaxis generally should be reserved for people at higher risk for influenza-related complications who have had contact with someone likely to have been infected with influenza. As an alternative to chemoprophylaxis, clinicians can also choose to counsel people at higher risk for influenza-related complications about the early signs and symptoms of influenza and advise them to immediately contact a health care provider for evaluation and possible early treatment if clinical signs or symptoms develop.

Post-exposure antiviral chemoprophylaxis with either oseltamivir or zanamivir can be considered for health care personnel, public health workers, or first responders who have had a recognized, unprotected close contact exposure to a person with confirmed, probable, or suspected 2009 H1N1 or seasonal influenza during that person’s infectious period.

However, use of recommended PPE and other administrative controls (e.g. having health care personnel stay home from work when ill, and triaging for identification of potentially infectious patients) should be used to reduce the need for post-exposure chemoprophylaxis among health care workers.

As an alternative to chemoprophylaxis, health care personnel who have occupational exposures, can also be counseled about the early signs and symptoms of influenza, and advised to immediately contact their healthcare provider for evaluation and possible early treatment if clinical signs or symptoms develop.  

Should antiviral agents be used for post exposure chemoprophylaxis in healthy individuals?

Antiviral agents are discouraged for prevention of illness in healthy children or adults based on potential exposure in community, school, camp or other settings. In addition, there are no safety data regarding long term or frequent use of antiviral agents in children, and limited data for healthy adults.

Which antiviral drugs should health care providers prescribe for chemophrophylaxis of 2009 H1N1?

For antiviral chemoprophylaxis of 2009 H1N1 influenza virus infection, either oseltamivir or zanamivir are recommended. Currently, circulating 2009 H1N1 viruses are susceptible to oseltamivir and zanamivir, but resistant to amantadine

What is the recommended duration for antiviral chemoprophylaxis if used following exposure to someone with influenza?

Duration of antiviral chemoprophylaxis post-exposure is 10 days after the last known exposure.

What is the treatment of choice for pregnant women with suspected or confirmed 2009 H1N1 infection?

Oseltamivir and zanamivir are "Pregnancy Category C" medications, indicating that no clinical studies have been conducted to assess the safety of these medications for pregnant women. Pregnancy should not be considered a contraindication to oseltamivir or zanamivir use. Because of its systemic activity, oseltamivir is preferred for treatment of pregnant women.

What side effects can occur with influenza antiviral drugs?

Side effects differ for each drug. If an antiviral drug has been prescribed for you, ask your doctor to explain how to use the drug and any possible side effects. Health care professionals prescribing flu antiviral drugs should alert patients about adverse events that can occur. For more information about side effects, see Antiviral Drugs: Summary of Side Effects.

Can antiviral drugs be helpful for people unable to take the flu vaccine?

Yes. CDC and ACIP recommend use of antiviral drugs for people allergic to eggs (which can cause them to have an allergic reaction to the vaccine) or for people who previously have encountered complications from Guillain-Barre syndrome (GBS) associated with influenza vaccination. In addition, taking antiviral drugs may be recommended among persons that may not have a good immune response to the flu vaccine.

Should people use antiviral drugs before or after receiving the live attenuated influenza vaccine (LAIV) called FluMist®

LAIV is one of two types of flu vaccine. It is given as a nasal spray and contains weakened, live virus. Flu antiviral drugs taken from 48 hours before through 2 weeks after getting LAIV can lower or prevent the vaccinated person from responding to the vaccine and the person may not get immune protection from the vaccine.

Antiviral drugs can be taken with the inactivated (i.e. killed) flu vaccine.

CDC: 2009 H1N1 Vaccination Recommendations

With the new H1N1 virus continuing to cause illness, hospitalizations and deaths in the US during the normally flu-free summer months and some uncertainty about what the upcoming flu season might bring, CDC's Advisory Committee on Immunization Practices has taken an important step in preparations for a voluntary 2009 H1N1 vaccination effort to counter a possibly severe upcoming flu season.

2009 H1N1 Vaccine

Every flu season has the potential to cause a lot of illness, doctor’s visits, hospitalizations and deaths.  CDC is concerned that the new H1N1 flu virus could result in a particularly severe 2009-2010 flu season.  Vaccines are the best tool we have to prevent influenza.  

 

CDC hopes that people will start to go out and get vaccinated against seasonal influenza as soon as vaccines become available at their doctor’s offices and in their communities (this may be as early as August for some).  

The seasonal flu vaccine is unlikely to provide protection against 2009 H1N1 influenza.  However a 2009 H1N1 vaccine is currently in production and may be ready for the public in the fall. The 2009 H1N1 vaccine is not intended to replace the seasonal flu vaccine – it is intended to be used along-side seasonal flu vaccine. 
CDC’s Advisory Committee on Immunization Practices (ACIP), a panel made up of medical and public health experts, met July 29, 2009, to make recommendations on who should receive the new H1N1 vaccine when it becomes available. 

While some issues are still unknown, such as how severe the flu season, the ACIP considered several factors, including current disease patterns, populations most at-risk for severe illness based on current trends in illness, hospitalizations and deaths, how much vaccine is expected to be available, and the timing of vaccine availability.

The groups recommended to receive the 2009 H1N1 influenza vaccine include:

• Pregnant women because they are at higher risk of complications and can potentially provide protection to infants who cannot be vaccinated;
• Household contacts and caregivers for children younger than 6 months of age because younger infants are at higher risk of influenza-related complications and cannot be vaccinated. Vaccination of those in close contact with infants younger than 6 months old might help protect infants by “cocooning” them from the virus;
• Healthcare and emergency medical services personnel because infections among healthcare workers have been reported and this can be a potential source of infection for vulnerable patients. Also, increased absenteeism in this population could reduce healthcare system capacity;
• All people from 6 months through 24 years of age
  • Children from 6 months through 18 years of age because cases of 2009 H1N1 influenza have been seen in children who are in close contact with each other in school and day care settings, which increases the likelihood of disease spread, and
  • Young adults 19 through 24 years of age because many cases of 2009 H1N1 influenza have been seen in these healthy young adults and they often live, work, and study in close proximity, and they are a frequently mobile population; and,
• Persons aged 25 through 64 years who have health conditions associated with higher risk of medical complications from influenza.

No shortage of 2009 H1N1 vaccine is expected, but vaccine availability and demand can be unpredictable and there is some possibility that initially, the vaccine will be available in limited quantities.  CDC Advisors Make Recommendations for Use of Vaccine Against 2009 H1N1.  

Once the demand for vaccine for the prioritized groups has been met at the local level, programs and providers should also begin vaccinating everyone from the ages of 25 through 64 years.

Current studies indicate that the risk for infection among persons age 65 or older is less than the risk for younger age groups. However, once vaccine demand among younger age groups has been met, programs and providers should offer vaccination to people 65 or older.