Combining DTP vaccine and H. influenzae type b vaccine – Haemophilus influenzae

Combining DTP vaccine and H. influenzae type b vaccine – Haemophilus influenzae – Tips from Other Journals

As additional parental vaccines are recommended for routine use in infants, the practice of combining multiple vaccines into one inoculation will become increasingly appealing. Ferreccio and colleagues conducted as study to assess the safety and efficacy of combining a vaccine against Haemophilus influenzae type b (purified polyribosylribitolphosphate conjugated to tetanus toxoid [PRP-T]) and the standard diphtheria-tetanus-pertussis (DTP) vaccine in the same syringe.

The study included 278 infants seen for routine well-baby examinations at threer community health centers in Chile. The infants were randomized into three groups: the first group received the combination of PRP-T and DTP in one arm and placebo in the other arm; the second received DTP in one arm and PRP-T in the other arm, and the third recived DTP in one arm and placebo in the other arm.

The infants were immunized at two, four and six months of age. All of the infants were observed for at least one hour after vaccination. They were also visited at home each day for four days after they were vaccinated. Serologic testing was performed in all infants to anlayze the immunogenicity of the vaccines.

The authors found that the PRP-T vaccine was safe and caused few side effects. The major side effect was an increased incidence of fever in patients who received the PRP-T vaccine, compared with patients who received only the DTP vaccine. The DTP vaccine was associated with local erythema and induration. One infant in the study died; the cause of death (sudden infant death syndrome) was not thought to be related to the vaccines.

The PRP-T vaccine was highly immunogenic, with appropriate serlogic responses noted after three doses in 89 percent of patients who had received the DTP and PRP-T vaccines combined in the same syringe. However, this response rate was significantly lower than the 98 percent response rate noted in patients who had received the immunizations in separate syringes.

The authors conclude that combining the DTP and PRP-T vaccines in the same syringe is a safe and attractive means of vaccine delivery. However, the degree of immunogenicity appears to be slightly compromised when the vaccines are combined. (Pediatric Infectious Disease Journal, October 1991, vol. 10, p. 764.)

COPYRIGHT 1992 American Academy of Family Physicians

COPYRIGHT 2004 Gale Group