August 26 – Cough, Cough

Today’s factismal: Fears of the DTaP vaccine in the 1970s and 1980s have led to the rise of vaccine-resistant whooping cough today.

This year’s Disneyland measles outbreak has shown what happens when a lot of people opt out of vaccinations; one infected person goes into an areas with a lot of unvaccinated people and before you know it, you have an outbreak. The same thing happened last year when an Amish missionary brought measles home to 383 people in Ohio. And it happened in 2013, when a Baptist missionary gave the disease to 25 members of his congregation in Texas. But there is a deeper story to the rise of this once-vanquished disease, and that can be discovered in whooping cough.

Whooping cough used to be an endemic disease; it was everywhere. Named for the “whoops” of air that victims would breathe in after prolonged coughing fits, whooping cough (or pertussis, as the medicos prefer to call it) is a bacterial disease that spreads through droplets sprayed out during the coughing. Pertussis patients would cough so hard that they would break ribs, lose bladder control, and even tear open the arteries in their neck! It wasn’t uncommon for a whooping cough victim to vomit or faint after a fit. And hard as it was on young children and the elderly, it was frequently fatal for infants; about 2% of all infants who came down with whooping cough died from the disease. That was some 1,000 children each year!

After the measles vaccine was introduced in 1963, measles cases dropped dramatically (Data from CDC)

After the measles vaccine was introduced in 1963, measles cases dropped dramatically
(Data from CDC)

Naturally, any disease that awful was researched pretty thoroughly. In 1906, doctors discovered the bacillus responsible for whooping cough. And in 1925, the first vaccine was used to control the disease. Soon the vaccine was being widely used and the number of pertussis cases was headed down after hitting a peak in 1931. In 1942, a more effective version of the vaccine was combined with vaccines to fight diphtheria and tetanus to create the first DTP vaccine. By1970, there were only 1,000 cases of the disease and it looked as if it might follow smallpox into obscurity. And then something awful happened. A few infants were reported to have suffered seizures after being injected with the vaccine. These isolated cases were widely reported on the evening news and a new syndrome was identified: pertussis vaccine encephalopathy.

Pertussis cases dropped after the vaccine was introduced in 1925 but have risen lately due to unvaccinated people (Data from CDC)

Pertussis cases dropped after the vaccine was introduced in 1925 but have risen lately due to unvaccinated people
(Data from CDC)

In response to the reports, many parents either spread out the DTaP schedules or stopped giving their children the vaccine altogether. Despite multiple follow-up investigations and numerous studies showing that the whole cell vaccine was safe to use, suspicion lingered on. A different form of the vaccine was created, one that used just fragments of the bacterium instead of the whole thing, but the damage was done; many people skipped the vaccine entirely. At first, the effect of the delays and opt-outs was subtle. Pertussis levels remained fairly steady through the late 1970s and 1980s. But then it started a slow and steady rise. The disease was coming back. Worse, thanks to the spacing out of the vaccinations, a new variant of the disease had arisen – one that the vaccine couldn’t target! And, to add insult to injury, it was found that the new version of the vaccine wasn’t as effective as the original and needed more frequent booster shots. As a result, the number of whooping cough cases in the US has risen from about 1,000 each year to 28,000 each year, with no sign of stopping. Barring a new, more effective vaccine that targets both types of the bacillus, the number of pertussis cases each year and the number of infants that die from it is just going to continue to rise.

Preventing measles, polio, pertussis, and a host of other diseases is just this simple (Image courtesy CDC)

Preventing measles, polio, pertussis, and a host of other diseases is just this simple
(Image courtesy CDC)

That may be where we are headed with measles. Thanks to the people opting out of vaccinations, outbreaks are getting larger and more common. And thanks to those who only take one of the required two doses, a more virulent form of measles will arise. Measles, like pertussis will become vaccine-resistant and children will start to die again.

What can you do? First, get all of your vaccines and keep them current by taking the booster shots. Once you’ve done that, then head over to the Measles and Rubella Initiative:
http://www.measlesrubellainitiative.org/

2 thoughts on “August 26 – Cough, Cough

  1. Pingback: September 9 – Rock A Bye Baby | Little facts about science

  2. Pingback: May 14 – Controversy | Little facts about science

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