Since the latter part of 2001, there has been a growing concern about the risk of biological terrorism. These concerns have in turn raised a potential role for smallpox vaccinations. Other vaccinations, for example, for Influenza, have been correlated, fortunately only rarely, with an increased incidence of Guillain-Barré Syndrome. Accordingly, a potentially increased role for smallpox vaccinations has, in turn, raised concerns about the possibility that it too might trigger Guillain-Barré Syndrome.

To look into the possibility that smallpox vaccinations might trigger GBS, the literature was explored for possible prior experiences or studies. Doctor Ch. Eggers, of The University Children's Clinic (Univ. Kinderklinik) of Heidelberg, reported in 1974 (Mschr.Kinderheilk, 122, 681) experience with post vaccination polyneuritis as a complication after smallpox vaccination. A translation from the original German, kindly translated by my wife, Susan, indicates the following.

Complications in children's nervous system after smallpox vaccination can occur both in the central nervous system (brain and/or spinal cord) as well as the peripheral nervous system, where damage in GBS typically occurs. In the brain, altered mental status (encephalopathy) occurs rarely, in approximately 1.5 to 2% of persons vaccinated. Other reports describe even rarer brain complications, at 1:10,000 to as low as 1:126,000 persons. The risk of developing peripheral nerve complications such as GBS is likewise extremely rare. For example, in 1968, a two year old girl apparently developed peripheral nerve inflammation (polyneuritis) after smallpox vaccination, with weakness of the legs. And, a two year old boy developed weakness and numbness of the legs twenty one days after a vaccination. Symptoms completely reversed by seven weeks later. Doctor Eggers goes on to explain that the clinical picture, spinal fluid and EMG findings in this young boy were consistent with typical findings of polyneuritis, implying that the boy had developed Guillain Barré Syndrome. Doctor Eggers went on, to explain that the incubation period, the time from vaccination until peripheral nerve damage develops, is in the range of 4 to 27 days, as is typical for GBS. These cases, again quite rare, followed a two to four week course, implying that children who develop a GBS picture after smallpox vaccination tend to recover within a month of these complications.

Bearing in mind that this case report is rather dated and the scope very limited, it appears that neurologic complications from smallpox vaccination, such as a GBS-like picture, tend to be extremely rare. And the rare patients who develop such complications apparently recover relatively rapidly. Accordingly, based upon at least this report, it appears that, with respect to effects on the nervous system, smallpox vaccinations for children are rather safe.