066 - Neurologic Complications Following the Administration of Vaccines and Serums: Report of a Case of Peripheral Paralysis Following the Injection of Typhoid Vaccine

NOTE TO READERS: Unfortunately, my free time this summer is very limited, so I won't be able to update VoT as frequently as I have been. I'll try to continue working on it as time permits though. It should pick back up in August.

So, now on to today's paper. It starts off with a case report (basically a well-documented anecdote) of a man who suffered a minor temporary nerve disorder after receiving a vaccine against typhoid. The man was admitted to a hospital with some problems of epilepsy, probably from alcoholism. While there, he was given the vaccine, as protection from hospital-acquired disease, I guess. Staff and patients there routinely received the vaccine with no problems.

At first there was no problem with this man, but then four days after getting the second dose, he had "foot drop." I guess this meant he wasn't able to move his foot as much as he should've been able to. They couldn't find any infection or anything, and tried treating it with different ways, but a month later it was still the same. After 3 and a half months though, it was almost completely recovered.

So the man's doctors diagnosed this as vaccine-induced peripheral paralysis. It seems a little post hoc, but no other explanation presented itself.

Then Robinson discusses nerve problems relating to vaccines and different kinds of serum in general. It seems like besides the rabies and smallpox vaccines, it's mostly sera that cause problems, which makes sense because I think at this time they were animal-derived (and thus liable to cause sensitivity reactions perhaps). But still somewhat a problem.

People weren't sure what caused the problems, though they had some suggestions: some kind of toxin, possible disruption of nerves somehow, or a contaminating pathogen like a virus. Robinson suggests that a virus would also be a problem in other kinds of injections, but it doesn't seem to be. And he adds one possibility: the preservatives used in these products.

Many of these products, and many of those producing them, used phenol-based preservatives, like phenol or tricresol, or others. Obviously preventing growth of bacteria in injectable products is a good thing, but some studies seemed to show similar serious nervous symptoms after injection with phenol-related compounds. Some seemed safer than others, though studies weren't entirely clear. So Robinson suggests recording whether each product contained a preservative when reporting this kind of side effect.

He concludes thusly:

"There is no way of knowing what patients may be unexpectedly affected by this unusual complication. The physician should not be held responsible for its occurrence, and the possibility of its happening is not a contraindication to the intended injection."

My conclusions: Not really sure. Doesn't seem especially relevant to the question of vaccine safety today, but worth paying attention in the future.

Citation: Robinson, L. J. Neurologic Complications Following the Administration of Vaccines and Serums: Report of a Case of Peripheral Paralysis Following the Injection of Typhoid Vaccine. New England Journal of Medicine 216, 831–837 (1937).