Forgot your password?
typodupeerror
Medicine

In Calif. Study, Most Kids With Whooping Cough Were Fully Vaccinated 293

Posted by timothy
from the conventional-wisdom-isn't-always dept.
An anonymous reader writes with this extract from a Reuters article: "In early 2010, a spike in cases appeared at Kaiser Permanente in San Rafael, and it was soon determined to be an outbreak of whooping cough — the largest seen in California in more than 50 years. Witt had expected to see the illnesses center around unvaccinated kids, knowing they are more vulnerable to the disease. 'We started dissecting the data. What was very surprising was the majority of cases were in fully vaccinated children. That's what started catching our attention,' said Witt."
This discussion has been archived. No new comments can be posted.

In Calif. Study, Most Kids With Whooping Cough Were Fully Vaccinated

Comments Filter:
  • So... (Score:5, Insightful)

    by SJHillman (1966756) on Thursday April 19, 2012 @11:17AM (#39734205)

    So... either their was something wrong with the vaccine, there was a mutation, or else this particular vaccine is less effective than most other vaccines. Unfortunately, most people will take this and generalize it to "vaccines don't work!!!"

    • by ClintJCL (264898)
      No, we will generalize it to "vaccines don't always work".
    • Re:So... (Score:4, Insightful)

      by LateArthurDent (1403947) on Thursday April 19, 2012 @11:23AM (#39734277)

      So... either their was something wrong with the vaccine, there was a mutation, or else this particular vaccine is less effective than most other vaccines. Unfortunately, most people will take this and generalize it to "vaccines don't work!!!"

      There's also the possible effect of non-vaccinated kids lowering the herd immunity. Basically increasing the chances of those who got the vaccine which for some reason or another wasn't effective in immunizing them to come in contact with the virus.

      Like you said, lots of variables, more study needed. We do need to verify the effectiveness of the vaccine (or even the effectiveness of a particular batch of the vaccine) is not being compromised.

      • by Nadaka (224565)

        If it was herd immunity, you would still expect to see a significantly higher number of infected amongst the unvaccinated.

        • Re:So... (Score:5, Insightful)

          by LateArthurDent (1403947) on Thursday April 19, 2012 @12:16PM (#39734953)

          If it was herd immunity, you would still expect to see a significantly higher number of infected amongst the unvaccinated.

          That's not necessarily true.

          Say the vaccine is 96% effective and we're studying a population of 1000 kids. If they were all vaccinated, and they all come in contact with the virus, you'd expect roughly 40 of them to still get sick. If 30 of those do not get vaccinated, and all 1000 were exposed to the virus, you'd have a cap of 30 non-vaccinated kids getting sick, but still roughly 39 of the vaccinated kids will be sick, simply because there are more of them.

          The total amount of people with the disease goes up significantly, but most of the people coming down with the disease are still people who were vaccinated. If you stop assuming all those people came in contact with the virus, the fact that there are now 30 kids who weren't vaccinated increases the chance of 39 kids for whom the vaccine didn't work to come in contact with the disease, so there's a larger proportion of vaccinated kids getting sick.

          • Re:So... (Score:4, Informative)

            by atamido (1020905) on Thursday April 19, 2012 @01:16PM (#39735687)

            Say the vaccine is 96% effective and we're studying a population of 1000 kids. If they were all vaccinated, and they all come in contact with the virus, you'd expect roughly 40 of them to still get sick. If 30 of those do not get vaccinated, and all 1000 were exposed to the virus, you'd have a cap of 30 non-vaccinated kids getting sick, but still roughly 39 of the vaccinated kids will be sick, simply because there are more of them.

            The total amount of people with the disease goes up significantly, but most of the people coming down with the disease are still people who were vaccinated. If you stop assuming all those people came in contact with the virus, the fact that there are now 30 kids who weren't vaccinated increases the chance of 39 kids for whom the vaccine didn't work to come in contact with the disease, so there's a larger proportion of vaccinated kids getting sick.

            I wish I had some mod points from you because this is the critical piece that most people miss. Vaccines aren't 100% effective, and small number of unvaccinated kids can be the tipping point to infecting the kids with responsible parents.

      • Re:So... (Score:5, Informative)

        by Moryath (553296) on Thursday April 19, 2012 @02:09PM (#39736343)

        Bingo!

        Not only that: the non-immune kids, once you break past herd immunity numbers, become the incubators of the mutations that break out of the vaccination wall.

        Of the 132 patients under age 18, 81 percent were up to date on recommended whooping cough shots and eight percent had never been vaccinated. The other 11 percent had received at least one shot, but not the complete series.

        So:
        81% fully vaccinated.
        11% incomplete.
        8% unvaccinated.

        Threshold for herd immunity: generally considered to be at 92% minimum [wikipedia.org] for pertussis.

        In other words: the unvaccinated/incompletely-vaccinated 19% broke herd immunity. Once that happens, you have an incubation dish for mutations, you have transmission vectors to those for whom the vaccine is out of date or has not worked as well as hoped.

        The rate of cases for each age, two through 18 years old, peaked among kids in their pre-teens. Among fully immunized kids, there were about 36 cases for every 10,000 children two to seven years old, compared to 245 out of every 10,000 kids aged eight to 12. "The longer you went from your last vaccine, the greater your risk of disease," Witt told Reuters Health. At age 13, the number of cases dropped, presumably because that's the age when children are eligible for their booster shot.

        Aha! The REAL pattern begins to emerge:

        Broken herd immunity lets the disease in: those with incomplete vaccinations begin to be affected at higher rates than those who have received the booster shot. In essence, age 12 - due to the pacing of the booster shots - is effectively a risk zone.

        This is why "religious objections" for booster shots are such fucking bullshit: being unvaccinated DOES cause societal risk. We need 92% minimum coverage for herd immunity and we do not have it.

    • Re:So... (Score:5, Informative)

      by mcmonkey (96054) on Thursday April 19, 2012 @11:26AM (#39734313) Homepage

      So... either their was something wrong with the vaccine, there was a mutation, or else this particular vaccine is less effective than most other vaccines.

      Or the booster given at 11-12 should be given at 8-9.

      Unfortunately, most people will take this and generalize it to "vaccines don't work!!!"

      Yeah, there is that. Though there really isn't enough detail in the article to make that conclusion.

      Of the whooping cough cases, 81% were fully vaccinated, 11% were partially vaccinated, 8% were not vaccinated. If more than 8% of the population was not vaccinated, then you could start down the path to building a case against vaccination.

      • Re:So... (Score:5, Informative)

        by geekoid (135745) <dadinportland @ y a hoo.com> on Thursday April 19, 2012 @11:47AM (#39734619) Homepage Journal

        The story point to the vaccine schedule in California needs to be updated to the CDC recommendations. Nothing more.

      • by Kozz (7764)

        Unfortunately, most people will take this and generalize it to "vaccines don't work!!!"

        Yeah, there is that. Though there really isn't enough detail in the article to make that conclusion.

        I don't think that's ever stopped the anti-vaxxers.

      • by eulernet (1132389)

        No, you should count everybody (ill and not ill).

        Perhaps 100% of the unvaccinated 8% got ill, but only 10% of the vaccinated 81% got the whooping cough.

        And there is another thing: when you get ill, you build antibodies, so you won't become ill for at least 10 years.
        With vaccine, you need to vaccinate after a few years.

        I don't think that whooping cough is deadly, so not vaccinating against it is not unwise.
        But if the illness has a letal risk (like measles), it's just stupid to avoid vaccines.
        Between autism a

        • by chebucto (992517)

          No, you should count everybody (ill and not ill).

          Perhaps 100% of the unvaccinated 8% got ill, but only 10% of the vaccinated 81% got the whooping cough.

          Read his post again. That was the point he was making: if more than 8% of the student population was _not_ vaccinated, then the non-vacciated people had a lower rate of infection than the vaccinated people. Of course, if less than 8% of the student population was not vaccinated, then the non-vaccinated people had a higher rate of infection than vaccinated pe

    • by TheSunborn (68004) <tillerNO@SPAMdaimi.au.dk> on Thursday April 19, 2012 @11:26AM (#39734319)

      No, the vaccine worked. The reason most of the children who got infected also had the vaccines, was that 81% of all children had recieved the vaccine. The risk of getting the infection was still greater for the children who newer got the vaccine.

      So the correct headline would be "Vaccine not as effective as previously thought".

      • by StikyPad (445176)

        I think TFA's headline was pretty accurate: Whooping cough vaccine fades in pre-teens.

        Among fully immunized kids, there were about 36 cases for every 10,000 children two to seven years old, compared to 245 out of every 10,000 kids aged eight to 12.

        "The longer you went from your last vaccine, the greater your risk of disease," Witt told Reuters Health.

        At age 13, the number of cases dropped, presumably because that's the age when children [were] eligible for their booster shot.

        The CDC is apparently now recomm

      • by digitig (1056110)

        No, the vaccine worked. The reason most of the children who got infected also had the vaccines, was that 81% of all children had recieved the vaccine.

        No, as I read it it's 81% of those with whooping cough who were infected. I can't see the proportion of the population who were vaccinated. It's an important point, though, and was my first thought. If 99% of the population is vaccinated, 100% of those not vaccinated get whooping cough and only 10% of those vaccinated get it then most kids with whooping cough would be fully vaccinated, by a factor of almost ten to one. Could they really have made such a basic statistical blunder, though?

    • Re:So... (Score:5, Informative)

      by Anonymous Coward on Thursday April 19, 2012 @11:27AM (#39734341)

      So... either their was something wrong with the vaccine, there was a mutation, or else this particular vaccine is less effective than most other vaccines. Unfortunately, most people will take this and generalize it to "vaccines don't work!!!"

      Not so. If the anonymous reader had read the entire article from which he or she posted, s/he would have seen that what was found is that researchers had overestimated how long the whooping cough vaccine was effective. So if a kid had gotten the original shot or booster shot fairly recently (didn't say how many years out it was good for), that kid did not develop the disease.

    • by Jawnn (445279)
      Nothing wrong with it, aside from it not being as effective as everyone would like it to be. Reducing an immunized kid's chance of getting a serious disease by 80% still seems like a good bet, unless your foil hat is on too tight or you still believe that floride is "a commie plot".
    • It's probably a breakdown in herd immunity [wikipedia.org]. Not everyone who gets the vaccine develops a strong immunity to it. But if enough of the population is vaccinated, the disease doesn't have enough vulnerable hosts to spread. In other words, vaccination doesn't just protect you, it protects the people you come in contact with, too.

      Sadly, with fewer people getting vaccinated, there's more of a chance for pockets of disease to linger, and catch not only unvaccinated people but also those who didn't respond strongly

    • Re:So... (Score:5, Informative)

      by garyebickford (222422) <gar37bic.gmail@com> on Thursday April 19, 2012 @11:53AM (#39734705)

      There's another possibility. I did not RTFA, so I don't know if the absolute numbers were in there, but if the number of unvaccinated kids is small relative to the number of vaccinated kids, then it could just be an artifact of the small numbers. There is a theorem in probability about this IIRC, but I forget the name. It's often mentioned with respect to false positives in blood tests, for example.

      If a blood test for a disease is 90% accurate for both positive and negative results (for simplicity we use the same value), but only 3% of the population truly has the disease, then the following can occur:

      Of the 3% that have the disease, 10% (0.3% of the total population) will show negative
      Of the 97% that don't have the disease, 10% will show positive - more than three times as many as the number who actually have the disease. This is the key fact - the results may be purely due to this kind of imbalance.

      Only the 2.7% that have the disease will correctly show positive. In the total population about 12.7% will show positive, of which over 3/4 will be false.

      Substitute vaccination for blood test - some small percentage of vaccinations will fail, but if the incidence of the disease is relatively quite small, that failure will show as a majority of those who have the disease.

    • No the article states that the immunity did not last as long as previously thought. Normally pertussis vaccine is given 5 times during childhood with the last booster at 12 years. In the outbreak, 132 cases of under 18 yr olds with pertussis were found. 81% of them had the full shots according to schedule while 11% had at least one vaccine. There were fewer instances of infection in the 2 to 7 year group ( when they get 3 boosters) compared to the 7 to 12 year old group (no boosters). Also the rate was
    • something wrong with the vaccine

      There's something wrong with every vaccine - 10% or so of the people don't get a sufficient immune response to get immunity. That's why it's more useful when more people get the vaccine.

      Unfortunately, some people take this as justification to use violence to vaccinate people against their will. I see far too little vaccine education in popular media venues (and the science is not taught in most schools).

       

    • by gweihir (88907)

      Don't forget that there are vaccines that only decrease the likelihood of infection and death. For example, tetanus vaccination only prevents outbreak for a few years, but prevents death from it for life. Well, mostly, were vaccinated people have a pretty high risk of death.

  • ...five times. Aside from having it when she was a child, during every one of her four pregnancies a test that suggested she still needed the vaccination and she was given it again.

    Surely the fifth time was the charm.

    • by geekoid (135745)

      What do you me "the charm"?
      They wear off.
      And the pregnancy shots are for the fetus's sake.

      • by toadlife (301863)

        I understand why the vaccinations are needed. We also made sure to get everyone flu shots every time she was pregnant. I just noting that the pertussis vaccination seems to be ineffective on my wife.

        I wonder if the increased number of children not being vaccinated is leading to a breakdown in the herd immunity that protects children for whom the vaccination doesn't work.

  • Vaccines aren't perfect, and with pertussis it's important to get them vaccinated as soon as most of them can mount an effective response. So if enough kids are vaccinated, the odds that the ones who do come down with it are vaccinated becomes greater than that they're unvaccinated.

    All in all a pretty basic exercise in high-school probability algebra.

  • by misosoup7 (1673306) on Thursday April 19, 2012 @11:27AM (#39734331)
    Let's put it this way. When you have a vaccine that works 95% of the time, and 99% of the kids are vaccinated. You'll have ~5% of the population contracting the disease despite being vaccinated. And the 1% of the population will contract the disease because they weren't vaccinated. You end with way more students that are vaccinated with the disease than those who are not vaccinated (absolute number wise). But it also ignored the fact that 94% of the population was protected against the disease.
    • by misosoup7 (1673306) on Thursday April 19, 2012 @11:31AM (#39734387)
      Also, the article clearly points out that the vaccine works, just it's effect wanes over time. And it is recommended to get a booster. This extract grossly misquotes the intent of the article and undermines the work that the medical community does.
    • by mcmonkey (96054)

      Let's put it this way. When you have a vaccine that works 95% of the time, and 99% of the kids are vaccinated. You'll have ~5% of the population contracting the disease despite being vaccinated. And the 1% of the population will contract the disease because they weren't vaccinated. You end with way more students that are vaccinated with the disease than those who are not vaccinated (absolute number wise). But it also ignored the fact that 94% of the population was protected against the disease.

      I'd like to know what % of children in CA are not vaccinated for whooping cough. TFA had the figure of 8% for the number of unvaccinated children in the population with whopping cough. If the number of unvaccinated children is much less than 8%, that'd be clear demonstration of the danger of not vaccinating.

      I also wonder if that 8% figure is low. Some folks don't vaccinate because of lack of education or access to medical care. But for the folks who actively avoid vaccination, how many of them refuse o

    • I read a quote somewhere that I thought was similar to your statement, that it is better (less likely to get a disease) to live in a community 95% are vaccinated and you are not, than to live in a community where you are vaccinated and 95% are not. It is called group immunity. Being vaccinated is not a guarantee that you won't get the disease, but when a large portion of the community is vaccinated, even those that are not vaccinated are less likely to get the disease.

  • by Yobgod Ababua (68687) on Thursday April 19, 2012 @11:29AM (#39734361)

    This actually makes perfect sense. Consider the following:

    1. Most children -are- vaccinated.
    2. Vaccinations do not really make you "immune" to catching a disease, they train your body to more efficiently fight it off.

    So, what happens is that the small percentage on unvaccinated children are bringing Whooping Cough back into contact with the rest of us, and those vaccinated children who perhaps don't have their immune system running at full capacity (tired, stress, fighting other illnesses, etc) catch it. Since there are statistically so many more of the latter available, it makes perfect sense that there are more cases in vaccinated children than unvaccinated.

    A more interesting statistic would be if every outbreak could be traced back to an unvaccinated "patient zero". I strongly suspect this is the case.

    • Re: (Score:3, Interesting)

      by Giftmacher (2621375)
      Exactly, what the study is highlighting is that the vaccine's efficacy may wane slightly earlier than expected which means the booster at 12 years of age is a bit too late to provide continuous protection. At worst the study is pointing to the need for additional/rescheduled vaccinations, not that the vaccine is ineffective. Moreover the article notes: "Ward, who did not participate in the new study, also said that immunized kids who catch whooping cough don't get as sick as unimmunized kids." If anyone
    • I don't know why everyone blames the unvaccinated.
      If there is anything that this article shows it is that the infected unvaccinated are a tiny minority and as such not significant.
      It also shows that vaccination is not a perfect shield/solution to decease, so your all outbreaks are caused by the unvaccinated is illogical.

    • by Yaddoshi (997885)

      Another possible theory (and I use the term theory because there are presently no unbiased studies that have looked thoroughly into both short term and long term effects of multiple vaccines being administered simultaneously to a human) is that the average child's immune system, which is known to be in its development stage until approximately eight years of age, has been partially compromised by receiving 21 vaccines (or more if they have received their yearly flu shot) by the age of six. Therefore the re

  • by sandytaru (1158959) on Thursday April 19, 2012 @11:35AM (#39734449) Journal
    The previous effectiveness was assumed to be 20 years, but it seems closer to 5-10. That is one reason that most colleges require proof of the 12 year booster (which is often given at age 18 since an incoming freshman needs it to start attending but most parents skip it in adolescence.)

    I caught whooping cough when I was 25 because I had not had the booster since I was 12. I was also required to get a fresh TDaP at age 31 to start attending graduate school, again because the booster was assumed to wear off after 20 years.

    Perhaps they need to change the booster recommendations from every 20 years to every 10 years.
  • It is known the shot wears off, it is know that a booster at 13 should be done, and again in adults.

    There is no surprise here.
    The headline should read:
    "Study shows CDC correct. Booster should be given at 11, and not 13.'

    ""The longer you went from your last vaccine, the greater your risk of disease," Witt told Reuters Health."
    Oh really? How is an infectious disease Doc not already aware of this? I'm am not a Dr, but I have spent 12 years reading vaccine studies and even I am aware of that fact.

    I hope it's ju

  • We're here at Kaiser Permanente in San Rafael, where we've secretly replaced the fine vaccines they usually serve with Folgers Crystals. Let's see if anyone can tell the difference!

  • Unfortunately the Autism vaccine causes Whooping Cough. I read it in a scientician paper.

  • No vaccine is 100% effective, so some people who are vaccinated will catch the disease. Since the vast majority of people are vaccinated, it's no surprise that most of the victims were vaccinated.

  • by ShanghaiBill (739463) on Thursday April 19, 2012 @11:54AM (#39734709)

    According to the article, only 8% of kids were unvaccinated. So even if they were ten times as likely to get the disease, most of the cases will still be vaccinated kids.

    What TFA actually says is that vaccinated kids are LESS likely to get the disease, and kids with multiple booster shots are even less likely to get it. The article's conclusion is that the vaccines work, but they work even better with a booster. The misleading Slashdot headline and summary implies the opposite conclusion.

  • Misleading (Score:5, Informative)

    by hudsonj (2621771) on Thursday April 19, 2012 @12:07PM (#39734839) Homepage
    I used to expect a Slashdot poster to have either properly read or at least fairly summarize the article posted. This is the third time in a month period in which the title/summary has been misleading. It is this type of practice that assists the viral spread of the misleading headline/summary which eventually becomes the whole story for less discerning news sources. The Reuters headline itself is much more accurate "Whooping cough vaccine fades in pre-teens: study", based on the content of the article itself. The statistics seem to say (correctly) that an unvaccinated child is disproportionally more likely to be infected with whooping cough. The discovery was that the vaccine used on children did not appear to be as effective over time as the booster shot schedule expected. The length of time from the last booster shot is correlated to the an increased chance of infection, which was larger than expected in later years. The conclusion being this booster shot cycle should adjusted so booster shots occur more frequently. What would be more interesting is to discover whether it was the loss of herd immunity due to unvaccinated children which led to the outbreak. Vaccines are known to often be only effect 95-99% of the time and often fade over time requiring booster shots. As herd immunity levels decrease the chance of propagation throughout a population every time individuals are in contact increases. It possible and even likely that it was this loss of herd immunity that exposed the larger than expected "fading" in strength of the vaccine's effects, which otherwise would have remained relatively unrealized and unimportant.
  • This is one of those stories where there's actually something useful you can do. If you haven't gotten a Tdap booster as an adult yet, do so when you get your next Td booster. (You do get a Td booster every ten years, right? You don't want tetanus, do you? You know they used to call it "lockjaw", right? You know the bacteria that cause tetanus survive in the environment outside of living hosts, right?)
  • by Ranger (1783) on Thursday April 19, 2012 @02:21PM (#39736523) Homepage
    I thought it was bad enough there were global warming denialists running slashdot, but now antivaxxers. The people running this site should know better than to feed these trolls. What has this become? The last refuge of semi tech-literate libertarian nutjobs?

[Crash programs] fail because they are based on the theory that, with nine women pregnant, you can get a baby a month. -- Wernher von Braun

Working...