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Haemophilus influenzae type b (Hib) is a bacterial infection that causes meningitis in infants, especially in those below one year old. It is sometimes difficult to obtain good immune responses and protection in infants when using standard vaccines. Therefore, a new vaccine against Hib was developed in which a molecule from the bacteria was bound to tetanus toxin (Hib-TT). The safety and effectiveness of Hib-TT was evaluated in 77 healthy infants and in 10 infants receiving only diphtheria, tetanus, and whooping cough (DTP) vaccinations. Redness at the injection site, fever, or irritability were observed in under 15 percent of children. Protective levels of antibodies were found in 76 percent of children after the first injection, and this number increased after the second injection to 97 percent, while none of the control infants developed protective levels of anti-Hib antibodies. Among 66 children returning for follow-up at 18 months, 91 percent were still protected; the booster shot increased the number of children protected to 100 percent. Several types of antibody subclasses responded to the Hib-TT vaccinations, and the changes in levels of each are described. Antibodies against TT increased after the first, second, and fourth injections. The study suggests that vaccination with Hib-TT provides safe and effective protection against Hib infection, and does not interfere with immune protection against tetanus. (Consumer Summary produced by Reliance Medical Information, Inc.)

Guillain-Barr syndrome is a neurological condition characterized by paralysis, which becomes progressively worse. Although its cause is unknown, the condition usually becomes manifest after a viral infection, surgery, cancer and vaccination. Three children developed Guillain-Barr syndrome after routine Haemophilus influenzae vaccination. A 19-month-old girl with difficulty walking had a polyribosylribitol phosphate linked to diphtheria toxoid (PRP-D) vaccine, the vaccine given to prevent Haemophilus influenzae type b infections, at a well-child care visit. Although she had received other vaccines without incident, her inability to walk a few steps was investigated further. Examination of the patient's brain by computerized tomography (CT), the use of detailed cross-sectional X-rays used to visualize internal structures, yielded nothing unusual. Electromyography, recording the electrical activity in the muscle, revealed abnormal nerve functioning. The patient was discharged after three treatments with plasmapheresis, a process of removing the plasma portion of blood and replacing it with other fresh or frozen plasma, which improved nerve functioning somewhat. In a second case, a 20-month-old girl had a well-child visit, received routine vaccination, and several days later developed progressive muscle incoordination, and had episodes of screaming during sleep, coughing, gagging and difficulty swallowing. Test results were normal, but difficulty walking and swallowing continued. Two months later she was able to walk and run. In a third case report, a 33-month-old girl with leg weakness and uncoordinated muscle movements reported unusual crying during sleep after routine PRP- D vaccination. Two months later neurological evaluation was normal. The association between the PRP-D vaccine and Guillain- Barr syndrome has not been clearly established in this study and results should be conservatively interpreted. The incidence is assumed to be rare given the large number of vaccinations currently administered.