Why Whooping Cough Is Becoming Resistant To Vaccine
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February 11, 2013 1:17 p.m.
Dr. Mark Sawyer, Professor of Clinical Pediatrics, pediatrician and infections disease specialist, UC San Diego School of Medicine and Rady Children's Hospital in San Diego. Member of the CDC Advisory Committee on Immunization Practices.
Joanne Faryon, KPBS Investigations Desk
Related Story: Why Whooping Cough Is Becoming Resistant To Vaccine
MAUREEN CAVANAUGH: Are vaccines keeping up with our diseases? We will discuss a possible resurgence of whooping cough. This is KPBS Midday Edition. Researchers say they've discovered the first US cases of whooping cough that may be resistant to the vaccine. We will revisit a KPBS investigation into whooping cough investigation into how the vaccine may need to change. New research shows the number of drug-related murders is decreasing in Mexico. But the picture on overall safety in Mexico is still cloudy. And then a sweeping opera in the great tradition takes the stage as the San Diego Opera presents Samson and Delilah. I am Maureen Cavanaugh. KPBS Midday Editionis next. First the news. Today is Monday, February 11 here are some of the stories we're following in the KPBS news room. Roman Catholics in San Diego today are reacting to the startling news that Benedict is resigning at the end of this month. It's expected to be a tense debate this afternoon as the San Diego city Council decides whether to override Mayor Filner's veto of two positions on the port commission. And the average price of gasoline is up for the 14th consecutive day. So now we have the dollar in a past. Listen for the latest through the day right here on KPBS. Our top story on Midday Edition comes from a report published in The New England Journal of Medicine. Researchers US say they've found resistance to the vaccine and CDC is (inaudible) to draw closer to the study but vaccine persistence could be one reason why cases of whooping cough increasing. Last year 18 Americans died from the disease the need for a number of other effects including (inaudible) but coming up with formulas are safe and effective is extremely complicated. I'd like to welcome my guests, Joanne Faryon is KPBS investigations producer. Welcome to the show.
JOANNE FARYON: Thanks, Maureen. Nice to be here.
MAUREEN CAVANAUGH: Dr. Mark Sawyer is a professor of clinical pediatrics and infectious disease specialist at UCSD school of medicine and Rady Children's Hospital in San Diego. He's a member the CDC advisory committee on immunization. Dr. Sawyer, so much for joining us today.
MARK SAWYER: Good afternoon, happy to join you.
MAUREEN CAVANAUGH: Joanne, you raise the question about whooping cough vaccine in an investigation you did almost 3 years ago, remind us of the whooping cough outbreak we have the California.
JOANNE FARYON: Was 2010 the summertime we start getting reports of the County of San Diego the whooping cough cases that declared epidemic. To sum up basically the year in California 10 infants died from the disease, to if the babies were for San Diego County. 9000 people got from a disease really got we had heard much about. This was the worst epidemic estate in 60 years.
MAUREEN CAVANAUGH: As you did your research did you find a lot of people getting the disease had been vaccinated?
JOANNE FARYON: The site we started reporting at San Diego County two out of three people who were sick were up to date with their immunizations and I stay up to date because with coffee it more than one shot so they receive the series of shots they needed to get. We had our investigation into state data, a lot of counties actually did not keep good data we did manage to get a burst of California counties that have high rates of disease and begin to try to help. Looked about the date of the California actually gathered as well and according to those statistics 80% of the people who got sick had been immunized. So we felt us repeatedly when doing our data analysis.
MAUREEN CAVANAUGH: How was that being explained at that time?
JOANNE FARYON: A number of ways everyone agreed that the vaccine was not hundred percent effective if you look at the packaging manufacturer says it's 85% effective so scientists tell us when you have a disease in the vaccine is hundred percent you always find it among a group of immunize people, but we asked the question so not only were immunize people getting sick but the rate of disease have also increased. When I say rate, that's what they say one and how many in 100,000 people are getting the disease so when we look back at the historical data we also saw that before we had mass immunization rate of disease was 140 per 100,000. If we had mass immunization in 1970 it goes to one in 100,000. What we saw in California the rate of disease is now at 18 per 100,000 and in some counties like samples of this but it was 140 or 150 per 100,000 so the rate of disease is also increasing.
MAUREEN CAVANAUGH: Let me go to you, Dr. Sawyer, first of all what came out last week was information that was published in the New England Journal of Medicine that researchers discover the first US cases of whooping cough caused by a germ that may be resistant to the vaccine. With this new report, do you think there is no evidence to say that there is a vaccine resistant form of the disease in circulation?
MARK SAWYER: No I don't think we could go quite that far yet. The report last week describe strains of pertussis missing one of the components in the vaccine, but there are either two or four additional components depending on which vaccines we are talking about that are still present and were present in the strain so I think it's going to far to say it is completely resistant but it does raise the concern that if the bacteria is changing over time and losing components that are in the vaccine that the vaccine may not work as well as it used to work.
MAUREEN CAVANAUGH: Joanne hasn't there been evidence that some sort of different strain of Pertussis Vaccine resistant strain has shown up in other countries?
JOANNE FARYON: To expand on what Dr. Sawyer has said that is what the research was coming out of the late 90s, 1998 when a researcher Dr. Fritz my started observing the small changes and has Dr. Sawyer pointed out, the research never concluded that the vaccine would not work out, but that perhaps the vaccine would not be as effective. So if you have a combination of the string that maybe was changing, new vaccines, acellular vaccines, waning immunity, he might create a perfect storm you have increased vaccine failure. So a couple years ago when we did the investigation may travel to the Netherlands and interviewed a scientist who had for years been publishing information and here he was not well-received I have to tell you that the leading American expert Dr. James Cherry said we don't think he's right the CDC said we don't have evidence to suggest he was right so we called him today Dr. Fritz Moy and contacted him and asked him now that there is research suggesting that this change in the string, do you feel vindicated, so Dr. Fritz Moy, use of the Netherlands Center for infectious diseases here's what he had to say.
NEW SPEAKER: It's taking a long time I think if people had been more critical and more positive in 1998 we would have known much more now and we might even have better vaccines by now. So, in a way it is a little sad I think.
JOANNE FARYON: Will this finally do you think that the issue of making new vaccines on the table?
NEW SPEAKER: I think so. Because this is so clear-cut that one cannot get around it.
MAUREEN CAVANAUGH: Okay, but Dr. Sawyer first let me get your reaction to what Joanne has been saying and also is it my understanding you are saying that what we've seen from a report last week, we are not there yet and trying to get a new vaccine is that right?
Yeah for me the new report is another piece of the puzzle which certainly raises the question about the vaccine but even before the report the issue of needing a better vaccine was already on the table. It really started in the 2010 outbreak that Joanne referred to and all of the recognition of cases of pertussis and people that were already immunized that was really the beginning and the story has continued ever have been recent outbreak Southern California but other states in the data there shows the same thing that the immunity from vaccine although it's very good at the very beginning and children it starts to go way over just a few years. So there is no question that we need a better vaccine.
MAUREEN CAVANAUGH: Besides the fact that there may be one or two elements of this particular string of pertussis that are morphing anyway that the vaccine cannot cover, what could be other reasons be that the rates of whooping cough are increasing the way they have?
I think one thing people believe is that we've learned to recognize this disease much better particularly in older children and adults. When I was in training we thought only infants got pertussis but that is not the case. People of all ages are able to get pertussis and we also have better test to diagnose pertussis. We have a molecular test called PCR which identifies patients.
MAUREEN CAVANAUGH: How would, as you say maybe there's only one or two elements that have changed in the street and the vaccine is not covering. How much would that decrease the effectiveness of the vaccine?
I don't know that's certainly a very good question and I'm sure the CDC is going to now study many more strains. This report only included 12 strains from one city in Philadelphia but I think now the question needs to be asked how widespread is this phenomenon and what role does it play in the waning immunity. As I mentioned the data we have so far is that the vaccine does work very well for a short time. So the fact that these strains are missing part of the protein code of the bacteria may have to do with the decrease in immunity over time but does not present the vaccine from being effective at first at least based on what we know right now.
MAUREEN CAVANAUGH: How many booster shots are now recommended for maintaining immunity?
MARK SAWYER: That is a question that's being discussed right now at CDC. It is for adolescents and adults we currently only recommend a single dose of pertussis vaccine called Tdap. And we start getting that at 11 years of age and all adults are recommended, there's no booster for that but it's being actively discussed and I anticipate with that one or two years we will have a recommendation to boost with the vaccine while we are waiting for better vaccines to come along.
MAUREEN CAVANAUGH: Joanne, part of your report is on critics that say the vaccine companies are reluctant to go to the drawing board and to develop better vaccines for whooping cough or even flew because they don't think there's much of a profit in it?
JOANNE FARYON: We spent a lot of the time reporting in 2010 about this there's something called the clipper pertussis initiative funded by the vaccine makers and they do have influence over vaccine policies of reporting raise the questions and scientists we spoke with as well question the fact that if you are a vaccine maker and the recommendation is to say let's have the booster another shot I just want to say that I realize I'm calling them all pertussis vaccines but basically Dr. Sawyer, isn't it that you have five shots as a child, and you have this booster shot when you are older so it's really six pertussis/wishing whooping cough injections that you are getting?
MARK SAWYER: That's right, there are two different vaccines, one we use in young children and another one that starts in adolescence but yes you are right, altogether the normal series is six doses altogether.
JOANNE FARYON: So I think the question had become that if the recommendation is well we will have another blister we will have more shots it's very expensive to develop a new vaccine and a new vaccine may not work so you also take a big risk and spend a lot of money that where will the pressure, the industry to make new vaccines and actually one of the scientists we spoke with last year and a couple years ago Dr. James Cherry is really well known in America from UCLA, when it comes to whooping cough and he says, two, let the public has to put some pressure on vaccine makers and say we do want to vaccines.
MAUREEN CAVANAUGH: You think that's true, Dr. Sawyer?
MARK SAWYER: I think the pressure is there based on the experience in the last two years with widespread outbreaks occurring across the country. So I think the signal has been sent from what's happening that we need better vaccines. I know the CDC is interested in that and there is a group convening this March of scientists from the NIH and CDC and the industry to say well let's look at what are the possibilities and how can we get a better vaccine made?
MAUREEN CAVANAUGH: Isn't the whooping cough vaccine actually kind of a poster child for trying to balance safety and efficacy when it comes to making a new immunization, making a new vaccine because wasn't the whooping cough vaccine for want of a better phrase water down a little to make it more safe back in the 90s?
MARK SAWYER: Yes and that's a very interesting part of this whole story. The vaccine we used in the 80s and 90s we are now learning was more effective than the one that we have changed you, but the reason we changed is that the old vaccine has side effects which are considered unacceptable so we fended off treating a vaccine that does not work as well for one that is safer so that is the challenge for vaccine manufacturers is to, but the combination of a vaccine that works better than the current one, but does not come along with increased side effects.
MAUREEN CAVANAUGH: When people hear that a vaccine is perhaps not 100% effective like let's say this year's flu vaccine is only 60% effective they may not want to make the effort to get the vaccine. What do you say to that attitude, Dr. Sawyer?
MARK SAWYER: I certainly understand people thinking that way because we're split to some extent by some of our vaccines which are 95 or 90% effective. But if you step back and think about it for a minute, 60% effective is a lot better than 0% effective so if we have an intervention the decreased traffic accidents by 60% we would be ecstatic with that so from my point of view people should still get vaccinated at this time it's still the best thing we have to prevent pertussis or influenza.
MAUREEN CAVANAUGH: I was just going to ask you, Dr. Sawyer would you say the drug companies are now feeling some pressure, do you think the government needs to take some action and put a little bit more pressure on the vaccine makers, the pharmaceutical companies to come up with better vaccines?
MARK SAWYER: As I mentioned there is a meeting being convened with government authorities in the vaccine manufacturers together this March in Washington to talk about the problem and talk about what prospects manufacturers may already have, or what the science tells us about what directions to pursue. Unfortunately as I think you know making a vaccine is very complicated and you do have to weigh the efficacy versus the side effects. So I'm afraid it's going to be several years before we get a new vaccine.
MAUREEN CAVANAUGH: Just Joanne just to be clear and wrap up the conversation, during your research and investigation your report was never geared toward people who were in some way anti-vaccine?
JOANNE FARYON: I think it was the opposite. The reporting showed that effective vaccines are amazing. Whooping cough that was killing a high number of infants in the 40s and 50s basically was almost wiped out by vaccines. So I think what we were asking is vaccines can meet amazing in terms of stopping disease, so what's happened? The problem that we found is I think this conversation was not happening in a very public way among health officials at the time because I think there is fear that somehow we feed into the anti-vaccine community or this sentiment, and I think rather than discussing it might not be 100% effective but like Dr. Sawyer pointed out is 60%, 80%, 70% is better than nothing.
MAUREEN CAVANAUGH: I've been speaking with Joanne Faryon, KPBS investigations producer and Dr. Mark Sawyer he is a professor of clinical pediatrics and pediatrics infective disease specialist at the UCSD school of medicine. Thank you both very much.
BOTH: Thank you.