Transcript of Get Ready Report podcast Episode 18: “Preventing pneumococcal illness: Vaccines can prevent disease in all age groups"
William Schaffner, MD, an infectious disease specialist and co-chair of the Pneumococcal Disease Advisory Board within the National Foundation for Infectious Diseases, speaks about the importance of vaccines in preventing pneumococcal disease.
So what is pneumococcal disease and what causes it?
Pneumococcal disease is caused by a bacteria, the pneumococcus streptococcus pneumoniae, which many adults carry in their throats without symptoms. But from time to time it can get down into the lungs and cause pneumonia and it also has a propensity to get into the bloodstream and cause very serious septic bloodstream infections and it can cause what we call metastatic infections in different parts of the body. For example, in joints it can cause infectious arthritis, it can produce infection of the covering of the heart. You can get pericarditis and, of course, it can get into the central nervous system and cause meningitis, a very serious infection.
How many cases of pneumococcal disease occur each year in the United States and how many people die from it?
It is estimated that there are still 44,000 cases of this kind of invasive pneumococcal disease that gets beyond the lungs into the bloodstream and in other parts of the body. Fortu-four thousand a year, and the pneumococcus is said to be responsible for approximately 5,000 deaths each year in the United States.
What are the most common pneumococcal diseases?
Pneumonia is far and away the most common. In fact the pneumococcus is the most common bacterial cause of pneumonia, and as we may discuss a little bit further, it often complicates influenza. First you get influenza, which causes inflammation of your respiratory tract mucous membranes and then the pneumococcus which we may be carrying in our throats anyway, take advantage of that inflammation and cause pneumonia. And so that is the most common kind of infection that the pneumococcus causes.
Who is at greatest risk for pneumococcal disease?
As you can imagine, pneumonia being the big problem, the older we get the more likely it is that we will be at risk of pneumococcal disease. So advancing age is far and away the characteristic that predisposes people to pneumococcal disease. The very young also are susceptible to pneumococcal invasive disease, particularly bloodstream infections and meningitis. Under the age of 65 if you have underlying heart disease of any kind or lung disease, if you are immunocompromised, if you have diabetes — these are conditions that set you up for pneumococcal disease. And then there is one other characteristic that ought to be mentioned, one is that if a person has lost their spleen, usually as a consequence of trauma or surgery, they are at very high risk of pneumococcal bloodstream infections. We have also discovered people with asthma have an increased risk of invasive pneumococcal infection, as do cigarette smokers. So we have a whole list of folks who are at increased risk of this serious infection.
What is the best way to protect against pneumococcal disease?
The best way of course is vaccination, vaccination and vaccination. Conjugate pneumococcal vaccine is now routinely used for all infants and children in the United States, so that’s very important. And then we have another pneumococcal vaccine, pneumococcal polysaccharide vaccine, which is used in adults and is recommended for everyone in those risk groups that we’ve just mentioned. And I would say one other thing. Vaccinating against the pneumococcal infection per se is important but remember I said influenza can set you up for pneumococcal disease, so vaccination against influenza also offers some protection against pneumococcal disease and of course it’s now recommended by the (Centers for Disease Control and Prevention’s) Advisory Committee on Immunization Practices that all of us in the United States older than 6 months of age, all of us should be vaccinated against influenza annually.
Every year, infectious disease specialists urge people 65 and older as well as younger adults with certain risk factors to get their pneumococcal vaccines but still the public doesn’t seem to be getting the message. Why is that?
Let’s look at the bright side. Physicians first of all have to get the message, and I think physicians and the public are doing a better job in vaccinating people age 65 and older. So in a stepwise fashion, we are seeing vaccination rates against pneumococcal disease increase in people age 65 and older. And of course pediatricians and family docs are doing a terrific job in vaccinating infants and young children. So it’s that group in the middle where we have the biggest problem. And you are exactly right, doctors have a hard time identifying patients in their practice with these underlying conditions and the public has not yet been very well educated about pneumococcal disease and how important it is. So we need to keep working on that and having conversations such as this so we raise the awareness of both physicians and the public about the importance to deploy pneumococcal vaccine.
For instance, a young man of perhaps 28 years old who has asthma, we would need to raise awareness that he needs to get a pneumococcal vaccine, correct?
Yes, absolutely. And particularly the recommendation for immunizing people with asthma and people who smoke is a relatively new recommendation — about two years ago from the Advisory Committee on Immunization Practices — so the word on that has not yet penetrated certainly the public and even physicians. So continuing education to get the word out and to help physicians also organize their practices so that these patients are identified efficiently and then routinely offered pneumococcal vaccine.
Why does seasonal flu put people at increased risk for pneumococcal disease?
Influenza, as we all know, principally infects the respiratory tract and it causes inflammation of those mucous membranes. And when that happens, if we happen to be carrying pneumococci at the time, those pneumococci can take advantage of that inflammation and get down lower into the respiratory tract and indeed into the lungs. And that’s a setup for those pneumococci to multiply and to cause bacterial pneumonia as a follow on complication of influenza.
Will getting the influenza vaccine help people avoid pneumonia and if so, why do they need both the pneumonia and influenza vaccines?
Individuals should get both. It’s now recommended that everyone receive influenza vaccine and those individuals for whom pneumococcal vaccine is indicated should get that vaccine also, definitely. Now, influenza can affect the respiratory tract and cause inflammation, and that’s a setup for complicating pneumococcal infection. We call that a secondary infection or a super infection. They work hand-in-hand, so what we need is protection against both and of course influenza vaccine is not sufficient because we need protection against specifically pneumococci. So for those people for whom it’s indicated that they get both, they really should get both vaccines.
At what point in the season is it too late to get the influenza vaccine?
Influenza peaks usually in the United States in February. It varies a little bit from year to year but usually in February. So if you haven’t gotten vaccinated by February, it’s starting to get too late, even though we continue to have influenza into March. So if you weren’t vaccinated at the beginning of February I would run, not walk, to get my influenza vaccine. But even more importantly, I think folks should determine next season, everyone should get vaccinated, get vaccinated yourself and make sure everyone in your family and your relatives are vaccinated because now we should all be vaccinated against influenza. Each year in the Untied States all of us who are older than age 6 months.
How good was the match this year for seasonal flu?
Actually, very good. The regular seasonal vaccine protects against three strains. You’re really getting three vaccines in one and this year the match was really very good against the three strains that were out there causing influenza. And even when the match is not perfect, when that wily influenza virus mutates a little bit, the vaccine almost always provides at least partial protection against strains that mutate slightly. So getting the vaccine is important each and every year.
Could you just touch a little bit more on how pneumococcal disease is transmitted?
It’s a bit subtle. Pneumocci are capable of residing back in our throats for a considerable period of time. So close contact, one person to another, is the way the pneumococcus gets from one person to another, usually within three feet, the breathing zone, and then of course we hug and kiss our relatives and friends and that all provides an opportunity for the pneumococcus to spread. But while it’s being carried it doesn’t cause any illness — it resides there quietly. But then, if you happen to have an underlying illness like chronic lung disease or some sort of heart disease, or you have diabetes, if that bug — the pneumococcus — gets from your throat down into your lower respiratory tract, then it can go ahead and set up pneumonia. So it can spread person to person, and then it lurks, waiting for an opportunity to cause disease.
What is the one thing you would like the average American to know about pneumococcal disease?
I would like the average American to become familiar with pneumococcal disease. It’s a little bit difficult, because it’s a long, funny word for the average American. That pneumococcal disease can produce serious pneumonia and bloodstream infections and meningitis and that there are vaccines available to prevent it.
Is it true that pneumococcal disease can be treated very effectively?
It can be treated very effectively with antibiotics, but here’s several things to keep in mind. The first is, the most serious kinds of pneumococcal infection, bloodstream infection and meningitis, even in the face of effective antibiotic therapy — and I want to repeat that, even in the face of effective antibiotic therapy — have mortality rates, death rates, of somewhere between 15 and 20 percent. So treatment is not the complete answer. Furthermore, the pneumococcus has started to get resistant to many first-line antibiotics, making treatment more difficult, and that’s all the more important therefore that people get vaccinated to prevent the disease on the front end, in other words we can’t rely on therapy to bail us out all the time. It comes back to prevention, as we all know an ounce of prevent is more important than a pound of cure. So prevention on the front end continues to be the highest goal of medicine. I would rather prevent pneumococcal disease than treat it.
Interview conducted by Teddi Dineley Johnson, The Nation’s Health, APHA
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