The complexity of Whooping Cough


pertussisby Nathan Reading

Whooping cough outbreak in Boulder
[Via Bad Astronomy]

Medical officials are saying that there have been 37 cases of pertussis — whooping cough — reported in my hometown of Boulder so far this year.

We’re not even 100 days into 2012 yet. [Note: Washington State is in the midst of an actual epidemic of pertussis.]

How serious is this? 30 of those Boulder cases are in children under the age of 18… and it almost took the life of six week old Natalie Schultz. The local news reported on this:


Anti-vaxxers and those opting out of vaccines are a problem, especially as they reduce the herd effect making it more likely unprotected members of the community become sick.

But things may be a little more complex than just blaming anti-vaxxers. Not enough to let them off the hook at the front lines of these problems but maybe enough to see that everyone may have a role here.

Whooping cough is highly infectious – one person can pass it on to 12-17 and requires vaccination rates of over 90% for herd immunity to work.

But it can be more complex than that. Pertussis is a sneaky disease. Even natural infection does not provide lifelong immunity. Vaccination provides perhaps 10 years of protection and booster shots are needed, even in adults.

Few adults get booster shots yet may not be protected, especially with spreading the disease.

Also, some of the newer vaccines  while having fewer side effects and adverse reactions, may not even be providing as many years of immunity as the older vaccine. So boosters every 5 years may be recommended.

In fact, it has been recommended that all adults be vaccinated against whooping cough. So some of the loss of herd immunity may come from waning immunity is previously vaccinated adults, who then help spread the disease. Because whooping cough in adults may be underreported as it seems much more like a normal cough.

Even more worrisome is that because protection against whooping cough is short-lived, natural selection may be helping the bacteria evolve into forms that could evade the vaccine.

Influenza virus evolves rapidly to evade our immune system, meaning that we have to get new vaccines every year. While the bacteria that causes whooping cough may never become that revolutionary, there are indications that some strains are evolving ways to evade the immune system.

So while the major problems with whooping cough  are social in nature and can be dealt with – no opting out and adult vaccination – there needs to be some recognition that even that might not eradicate the disease if we are also applying Darwinian pressure for the bacteria to evolve.

We will just have to be ‘smarter’.

7 thoughts on “The complexity of Whooping Cough

  1. Just a couple of comments: There are still an amazing number of people around who still remember the days before vaccines for everything. People who still have a problem due to polio, measles, mumps, chicken pox, etc. And anyone who has ever heard a small child with whooping cough will do almost anything to never hear it again.

    1. The refusal of some people to be vaccinated in the major cause of loss of herd immunity. But, it may also being lost due to the inability of vaccination to last more than 10 years and the continuing evolution of the bacteria.

      What may be happening is that adults still get the whooping cough but at a lower level than unvaccinated children. Thus they can still spread it and act as reservoirs for evolving bacteria that evade our vaccines.

  2. Dear Richard
    We rarely disagree – but in the case of vaccination we do. Most of the diseases that we vaccinate for are diseases that humans have created a significant herd immunity too. As you will see from the link here – nearly all had been reduced over time to being not agressive and affected few people. The immunity granted over centuries was real.

    Vaccination has often since then as you point out pushed the disease to be more agressive. The immunity granted is minimal and often short lived. In the case of flu – there is no change in the numbers when we get the strain wrong.

    Better overall immunity might be the best way to go – that is granted largely via diet

    Any way here are the numbers –

    1. Anything that helps our immune systems and keeps it healthy is very important. We agree there. However, diseases like the 1919 flu actually had a higher mortality for those who were the healthiest while often leaving children and the elderly alive. Life is just not simple.

      I’ve seen nothing saying the diseases are more aggressive. But just like with antibiotic resistance, the infection agents are under selective pressure to evolve ways around the immunity.

      Vaccines remain a necessary tool. But I think we can do better. A good vaccine should mimic an infection as much as possible without the person actually getting sick.

      Many vaccines today are based on processes from the early 20th century – or even earlier – when we had a very poor understanding of the immune system. Now we have a better understanding and should move those processes into the 21st century.

      Because there will always be emerging or evolving diseases that overwhelm our immune systems and kill a large percentage of people. That is life on Earth.

    2. I think we are largely in agreement – but from a Godlike perspective: might it not be best if we evolved with disease as they do with us? Of course politically none of us want to die or have our kids die

    3. Recognizing that we are part of the natural world is, I think, an important aspect of modern human existence. One that many, many people simply fail to recognize.

      Problems often arise when people do take a God-like perspective and forget that basic fact. It is not our tools – such a vaccination – that are a concern as much as our inability to believe that we are imbedded in a natural world just as every other organism on Earth and are not set apart on some higher level.

      We continue to evolve. We do things all the time, though, that lessen the direct effects of natural selection on the population – virtually all of medicine relies on this. Most animals on Earth die when they break a limb. Not us.

      We have evolved with disease in the past. And we continue to evolve. We just evolve slower due to infectious disease than we used to.

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