Building a better vaccine

A whooping cough vaccine introduced in the 1990s has fewer side effects than its predecessor, but it may not protect against the disease as well, Nathan Seppa reported in “Whooping cough bounces back” (SN: 4/19/14, p. 22). The old vaccine used whole cells of the pertussis bacterium, while the new acellular vaccine uses only components of the disease-causing cells.

Vaccinations are a hot-button topic, with some parents worried about possible side effects and others worried about the spread of illness from unvaccinated kids. Reader response to the whooping cough story reflected this growing unease. “Here’s a novel idea: Give parents a choice of which vaccine to use,” wrote Kim Dominguez on Facebook. “Many would choose the more effective one. Anyone who has seen someone suffer with whooping cough would choose to take the benefits of vaccination over the potential risks.”

Ted Grinthal suggested a combination of both vaccines: “I wonder if we can have the best of both worlds. Would it be effective to use the acellular vaccine for the first three shots — until the child is 18 months old — and then give the old whole-cell vaccine? That way, we’d avoid the unpleasant side effects until the children and parents are more able to deal with them.”

Pediatrician Stanley Plotkin, who helped develop the rubella vaccine, cautions that scientists don’t know whether using the vaccines together would provide the needed protection. “The use of the whole-cell vaccine after the initial vaccination in the first year of life might be a good idea, but we don’t know yet if that would correct the immunological defects of the acellular vaccine. And I doubt if American parents will accept the reactions, even later in life. I do not doubt that the whole-cell vaccine would be effective if enough doses were given, but I think the way forward is to improve the acellular vaccine. The acellular vaccine does protect infants when given in the first years of life; it just doesn’t protect long enough.”

On shaky ground

New early warning networks could provide alerts a few seconds before earthquakes hit, as Alexandra Witze described in “Buying time” (SN: 4/19/14, p. 16). These systems work by detecting the primary seismic waves, or P waves, that arrive before the more damaging secondary waves.

Reader David Reynolds e-mailed the story of his frightening experience with a magnitude 9.2 earthquake, the second largest in recorded history, which led him to believe P waves could help provide early warnings. “I was at the corner of 15th Avenue and Juneau Street in Anchorage when the Good Friday quake struck in 1964. A week after the quake, I was working in an office with about 20 other people at Ft. Richardson when, without saying anything, everyone in the office suddenly jumped to their feet and started running out of the building. No noticeable shaking had started. About 15 or 20 seconds later, we had a 7.5 aftershock. Although none of us knew what we were experiencing at the time, I’m sure now that we must have been sensing the P waves.”

People can absolutely feel P waves, says Witze. “Trained seismologists in particular can detect them and they will start counting as soon as they feel them, to determine the seconds elapsed until the secondary waves arrive. This allows the researchers to calculate a rough distance to the epicenter.”

The kangaroo solution

In “Kangaroo gut microbes make eco-friendly gas” (SN: 4/19/14, p. 10), Beth Mole described how bacteria called acetogens in the marsupials’ guts outcompete methane-producing microbes, minimizing kangaroo’s greenhouse gas emissions.

“If cattle could tolerate a move to acetonic bacterial fermentation, we could revolutionize American beef production,” John Turner wrote online. “Otherwise, why not cultivate red kangaroos instead? They’re no less native to North America than our present beef cattle. We’d just need some serious stock fences, rather Jurassic Park–looking ones.”

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