Contagion

September 14th, 2011

A new movie called Contagion opened last week and it has caused quite a stir in both public and scientific circles. I saw the film yesterday and have some thoughts. I would strongly recommend seeing the film if you can. The movie is about the sudden emergence of a new viral disease that is very much like a new strain of influenza. It is not influenza, but many of its characteristics are similar to it, so you can use the film to understand some things about influenza.

People ask me if the movie is realistic. Yes, I think it is, at least the first half of it when the pandemic is just starting. The second half shows the middle and end of the pandemic, which has not occurred in the US recently, so we have no way of knowing if it is accurate or not. What you see in the movie is pretty much the way hospitals and the CDC would react initially. The scenes of the CDC were shot on location. The characters in the film are very accurate portrayals of real microbiologists and epidemiologists. Everyone I work with looks like Kate Winslet (just kidding). They got all the terms and concepts right and pronounce all the words correctly. You can tell they had good coaching from expert consultants during the filming.

There are a couple of things in the film that I would question, but the writers made choices and I would not have made those choices. The film shows a cluster of cases in Minneapolis, and the investigation of those cases by the CDC representative (Ms. Winslet) faced some barriers and overall snottiness by the Minnesota Department of Health people. That would never have happened. The Minnesota Department of Health is probably the best in the nation. We in other states dream about being as good as they are.

The other thing I noticed had to do with the vaccine that researchers eventually produced. One of the researchers injected herself with an investigational vaccine before it was fully developed, and I don’t think that would have happened. Also, the film stated that an injectable subunit vaccine did not work but a live attenuated vaccine given intranasally did. The writers obviously drew from the current influenza vaccine situation for that. That is pretty unlikely; I think both vaccines would have worked, although they might have chosen the intranasal product because it could have been produced faster.

Those are about the only things I noticed in the movie that I would have done differently, after seeing it only once. I may watch it again and see if I can notice more.

New recommendations

August 18th, 2011

The new (2011) recommendations on influenza immunization from the Advisory Committee on Immunization Practices were released today. The recommendations are not really different from last year’s, but this document includes some new information that may answer some questions people have about the topic.

This year’s vaccine is made from the same virus strains as last year’s vaccine. Some peoople have questioned whether we need to get this year’s vaccine if we got one last year. The answer is yes. Protection declines over a year, and you need another immunization this year to give you optimal protection.

The document also explains the issue of egg allergy and flu vaccines. Flu vaccines are made in chicken eggs, and a very small amount of egg can sometimes be found in the vaccine. If someone is very highly allergic to egg protein, they can have a reaction to the vaccine. This kind of allergy is very rare. Many doctors prefer not to immunize someone who says they once had a “reaction” to eggs. The guidelines clearly say that most of these people can and should get their annual flu immunization, but they may need to be observed for a little while after their dose or they should be seen by an allergist before they take the vaccine. Too many people are being excluded from protection against influenza because people don’t understand the egg connection. The recommendations include an algorithm that will help sort out the egg allergy issue.

New flu vaccines (sort of)

August 10th, 2011

Something new has been happening in the flu vaccine business. For about 40 years there has been just one vaccine for influenza. A trivalent (three strains) vaccine given by intramuscular injection (a shot). Although several pharmaceutical companies made vaccine, it was all nearly identical. Now we are seeing something new, although not as new as you might think.

Pharmaceutical companies are taking the same vaccine and packaging it into specialized products for special populations or markets. Economists call this market segmentation. You take a basic existing product and modify it slightly for specific groups of people to strengthen their relationship with it; make them feel like the product is just for them. The market for flu vaccine is only so big, so companies want to give people a choice and a reason to choose their product over the competitors.

Last year we saw a new high dose vaccine for seniors. Same vaccine, but packaged in a higher dose, and it has been very successful. Smart company. This year we have a new intradermal flu vaccine that avoids the long needle that so many people hate. Same vaccine but a lower dose and no scary needle. Next year we may have a flu vaccine with four strains in it instead of three. I don’t know how it will be marketed but the company will figure out a way to convince the target customers that this vaccine is just for them.

The only really new flu vaccine we have seen is the intranasal product, which is a completely different concept in vaccines.

Each of these specialized products is good for the intended customers and I think it is good that companies are trying to constantly improve their products. Just remember that the vaccine part of all flu vaccines is the same and the rest is about dose and delivery.

Universal flu vaccine

August 3rd, 2011

There is a news story circulating this week about the idea of a universal influenza vaccine that may not require annual booster doses. A group of scientists in the United Kingdom have developed a vaccine like this and they are testing it.

Influenza viruses change (mutate) very quickly. The parts of the virus that cause infection are molecules called proteins on the surface of the virus. Some artists picture these molecules as looking sort of like mushrooms on the virus surface, although we really don’t know exactly what they look like. The tops of these proteins cause the virus to attach to our respiratory tract and cause infection, and those parts change. We make new vaccines out of these new proteins each year as they mutate.

The people working on this project asked an interesting question. The tops of these proteins change a lot, but other parts of these proteins and other viral proteins don’t change as much. Why don’t we make a vaccine out of the parts of the proteins that don’t change so much and see if that works?

Apparently it does work. Humans develop antibodies (immunity) against these stable molecules too, and they may be protective. Maybe changing the vaccine recipe will allow us to give the vaccine less often. The interval would depend on how long our immunity lasts, not on how quickly the virus changes.

The story predicts that such a vaccine may be ready in five years. I would not count on that. If this approach seems to work, we may know how good it is in five years, but it takes a long time to test vaccines before they are approved by the FDA, and influenza is a seasonal disease, so studies can only be done during certain months of the year. It is nice to know that improved vaccines may be coming.

Flu season may be starting in Michigan

January 7th, 2011

A report yesterday from the Michigan Department of Community Health, which tracks reported influenza cases, indicated that the number of cases is rising in Michigan. The descriptive terms they use are that we moved from “sporadic” to “local” activity. Sporadic means that a few cases pop up here and there but do not spread from the first case to more than one person, starting an outbreak. Local activity means that the virus is spreading from person to person in some areas and the number of cases is increasing. It looks like flu season has started in Michigan.

Every influenza season is different. Some start early, some late, some spread quickly, some slowly, some virus strains cause severe disease, some milder, some seasons are short, some long, etc. This season seems to be a little late, to be starting slowly, and to cause milder symptoms than other years, although the season has just started and may get a lot worse.

So far, there are two strains of influenza circulating in the US at the same time. About 85% are strain A H3N2 and 15% are strain A H1N1, the same as last year’s virus. Both viruses are well covered by this year’s vaccine, so people who are immunized should be protected or have only mild symptoms.

Some people like to wait to be immunized until the influenza season starts, I suppose hoping that maybe there will not be an influenza season. Well, it is here and they should be immunized now. There is plenty of vaccine in the system and hospitals, county health departments, physician offices and retail phamacies all should have ample supply this year.

Future flu vaccines

November 26th, 2010

Although the influenza vaccine we use today is safe and effective, the way we make it is basically 50 years old. We still make this vaccine the same way we did during the Eisenhower years because it is so safe and effective, and the pharmaceutical industry and the FDA are extremely conservative. Drug companies still make money on flu vaccines and the FDA enjoys a low rate of side effects in people who take it, so why change a good thing?

We should update our flu vaccine production methods because the old methods are simply not good enough. It takes about 6 months to make a flu vaccine from start, through production and testing, to finished product. That is just too long. The H1N1 pandemic showed that new influenza strains can arise quickly and we need to make vaccines against them quickly. We now make a new vaccine every year, and that may not be the best approach. A recent article in The New England Journal of Medicine shows why the old technology is inadequate and why new technology should be used.

We make our current flu vaccine in chicken eggs because most strains of the virus grow in eggs. An influenza vaccine plant is actually a big chicken farm with a small drug laboratory next to it. Our vaccine production capacity is limited by the number of eggs we can get at the time we need them; a pretty strange situation if you think about it. Each influenza virus grows in eggs differently, so the process is inherently variable.

We make most other drugs through a manufacturing process that is fast and that we can control. We can grow the virus in other cells or we can produce the vaccine synthetically without eggs. Both of these methods would be faster and less variable than our current method.

Our current vaccines contain two virus proteins, called H and N, which change every year. Investigational vaccines use other proteins that are more stable, so we may some day have a universal flu vaccine that does not have to be given every year. Maybe some day we can take a flu vaccine every 5 or 10 years, like tetanus vaccine, instead of every year.

Televisions and cars sold well in the 1950s, but they have continued to improve since then, and no one still uses those products from that era anymore. We should not be satisfied with old vaccines just because they work. We can make much better vaccines using new technology and we should invest in improving the influenza vaccine.

Flu vaccine and egg allergy

November 24th, 2010

Some people have allergies to chicken eggs, usually to the protein in the egg white called ovalbumin.

Current influenza vaccines are made in chicken eggs because the virus grows in them and eggs are somewht readily available. Vaccine manufacturers kill the virus and extract the virus proteins from the eggs, but a very small amount of egg ovalbumin sometimes contaminates the vaccine after it is purified.

For many years, we wondered if the small amount of egg protein in some influenza vaccines would cause a reaction in people who were allergic to eggs. There were no good studies done on this question. Many people with reported egg allergies have taken flu vaccines for years with no problems.

The drug manufacturers did not want to take any risk for such reactions, so they have always said that people with hypersensitivity to eggs should not take the influenza vaccine. That might have been a safe thing for drug manufacturers to do, but it has not been proven, and it leaves many people unprotected who may need the vaccine.

A study recently published in the Journal of Allergy and Clinical Immunology and a position paper from the American Academy of Allergy Asthma and Immunology clarify this question. Egg allergy does not pose any risk to the patient for giving the current influenza vaccines. The amount of ovalbumin in curent vaccines is extremely low; lower than the level needed to cause a reaction.

The products and guidelines for this year’s influenza vaccine and immunization programs have been produced, most of the vaccine has already been given, and things probably will not change this year. I look for the FDA and the drug manufacturers to soften their language for egg allergy next year as these new data become known.

A year ago

October 19th, 2010

I am not one to observe anniversaries or reminisce about things on the day they occurred in the past, but the second week in October 2009 is important for flu. That is the week that the Fall H1N1 outbreak began, and it changed the way hospitals do things.

Our hospital had a large surge of patients come to the Emergency Department on one afternoon and evening. Most were not really sick, but they were slightly sick and very worried. The news story of the H1N1 outbreak had run that day, and many people convinced themselves that they had it and they were scared. Moreover, they decided to go to the hospital Emergency Department to be evaluated rather than their own doctor. Perhaps they did not have a doctor. Some doctors told their patients to go to the hospital. Regardless, we saw a large surge of patients that night, and we have since improved our ways of dealing with a sudden surge of people arriving at the hospital for any reason.

Another thing that changed was the way we look at influenza. Some of the people with H1N1 were severely ill and required care in the critical care unit. Some died. That was very unusual. Most people with flu in the past were not very sick, certainly not sick enough to require critical care-level care. This influenza could kill, and we learned to treat it with much more respect.

We changed how we diagnose flu. The popular rapid antigen tests (the “quick test” done on a throat swab) did not detect H1N1. Doctors had to use their clinical judgement and classic tests like culture rather than the quick tests. If it looked like flu and acted like flu, you assumed it was flu until proven otherwise, and you had to act immediately because of the severity of this new disease.

We also learned to treat flu early. If the patient was severely ill or getting worse quickly, the sooner the patient got antiviral drugs the better they did. You could not wait until more tests were done to begin treatment. Now we “pull the trigger” on treatment right away. The virus does most of its damage to the lungs early in the infection, and the earlier you treat, the more lung you can save.

Hospital staff learned to better protect themselves from contagious diseases during the H1N1 outbreak. Doctors and nurses learned to wear their masks and eye protection more often when doing patient care, and our policy requiring staff to be immunized against influenza every year was shown to be a pretty good idea.

You never want bad things to happen, but we learned some things in the H1N1 outbreak of October 2009 that made us a better hospital and enabled us to give better care to our patients.

Study shows flu vaccine prevents heart attacks

September 28th, 2010

A new study just published in the Canadian Medical Association Journal concluded that influenza immunization reduces the risk of heart attack (acute myocardial infarction) by 19% in people over the age of 40. The study covered seven flu seasons, from 2001 to 2007, and included 78,706 patients living in England and Wales, a huge population that was possible to study because of the national healthcare system database in the United Kingdom.

The main conclusion is not very surprising; other studies have shown similar effects. Influenza attacks the lungs and makes your heart work much harder to pump your blood through the congested tissue. If you are going to have a heart attack, it is more likely you will have it when your lungs are damaged from influenza. Conversely, protection from lung infection would remove this risk factor for heart attack. This is why people with cardiac diaease have always been considered a high-risk group that should get their flu shots every year.

In digging deeper into the results, you discover that the authors found a few other facts that I think are important but the popular press will probably miss. The study found that timing was important. People who got their immunization early in the season (from September to mid-November) were more protected from heart attacks (21% versus 12%) than people who got their vaccine later (from mid-November on). Flu is always around before the official flu season starts, and it seems like it is better to be protected early than to wait until the epidemic starts.

Another little fact reported by the authors was that you were not protected against heart attack if you were immunized the previous year but not the current year. Only the current vaccine protected you for the current flu season. You had to be immunized every year to be protected.

The authors did not extend the study to a financial analysis, but it seems clear to me that preventing a very expensive thing like a heart attack makes the flu shot even more cost effective.

This large population-based study reinforces things that we have been saying about influenza prevention: flu shots are cost-effective and cost-avoiding, get immunized every year, and get immunized early.

Givving flu shots to hospitalized patients

September 24th, 2010

Bronson Methodist Hospital is begining a program this week to offer influenza immunizations to patients in the hospital. Bronson has done this for many years and it has become a standard policy for most hospitals in the US. Some agencies that look at the quality of medical care even grade hospitals on how successfully they immunize inpatients.

Immunizing hospital patients during the influenza season is a brilliant idea for several reasons. Patients in the hospital typically have time for it so they don’t have to make an extra appointment and drive somewhere to get their immunization. Nurses typically give patients many other drugs for their primary disease, so one more is not much extra work. Patients who are in the hospital are typically sick with some other disease like heart or lung problems, and they are at high risk for influenza already. And including the cost of the vaccine in a hospital stay avoids the work of submitting another bill to your insurance. Studies show that immunizing hospital patients during the influenza season prevents readmission for influenza later and saves a lot of money.

Hospitals typically give only the intramuscular shots to inpatients because the intranasal mist vaccine is not approved by the FDA for patients who are sick.

Some people still question whether you should give a vaccine to a person who is in the hospital for another disease or condition. Other than treatments to suppress a patient’s immune system, no diseases or treatments make a patient inelligible for or interfere with the response of a patient to a vaccine. You can give a patient with pneumonia a flu shot. The shot will not harm the patient and the vaccine will work pefectly well in that patient after they recover and go home.

If you or someone you know is going into a hospital for any reason between September and April and you have not had your flu shot yet, go ahead and let your nurse give you one while you are there.