A phase IV open label study to assess the safety, tolerability and immunogenicity of a Haemophilus influenzae type B (Hib) CRM197 conjugated vaccine administered to healthy infants at 2, 4, and 6 months of age.

The objective of this prospective clinical study was to evaluate the safety, tolerability and immunogenicity of Chiron Hib vaccine (Vaxem Hib) in Thai infants. This trial was conducted at Bhumibol Adulyadej Hospital, Bangkok, Thailand from June to November 1999. Three intramuscular injections of the vaccine were given to 119 infants at 2, 4 and 6 months of age. Reactions and adverse events after the vaccination were recorded. Blood samples for anti-PRP antibody were collected before the first immunization, and after the second and third immunizations. After the second dose, 91% and 58% of the subjects had anti-PRP antibody titers of > or =0.15 microg/ml and > or =1.0 microg/ml, respectively. After the third dose, 99% and 90% of the subjects had anti-PRP antibody titer > or =0.15 mcirog/ ml and > or =1.0 microg/ml, respectively. Local and systemic reactions were mild and transient. The study indicates that Vaxem Hib vaccine is safe and well tolerated. Three doses of the vaccine are necessary to achieve adequate protection in infants.

Vacuna contra Haemophilus influenzae: perspectivas / Vaccine against Haemophilus influenzae: perspectives

Haemophilus influenzae serotipo b es el principal agente etiológico de meningitis bacteriana endémica en población infantil. Aproximadamente 80% de los casos con este padecimiento ocurre entre los dos a tres meses de edad y al final del tercer año de vida; el 20% restante habitualmente se presenta en niños de tres a seis años de edad; los adultos son raramente afectados. Actualmente en Estados Unidos la meningitis bacteriana tipo b ocurre con una tasa anual entre 19 a 63 por 100.000 niños menores de cinco años de edad. Existen datos que estiman que uno de cada 250 niños es susceptible de contraer la enfermedad antes de los cinco años de edad