[Absence of meningitis caused by Haemophilus influenzae type b in The Netherlands following twofold vaccination].

OBJECTIVE

To determine the two-year results of nationwide vaccination with Haemophilus influenzae type b (Hib) vaccine on the occurrence of Hib meningitis in the Netherlands.

DESIGN

Retrospective controlled study.

SETTING

The Netherlands.

METHOD

Children born since April 1, 1993 are vaccinated at the age of 3, 4, 5 and 11 months to protect them from infections with Hib. The number of Hib meningitis patients in the period 1 April, 1993 to 1 April, 1995, among infants born in this period who were offered the Hib vaccine (study group), was compared with the number of Hib meningitis patients in the period 1 April, 1991 to 1 April, 1993 among children born in last-mentioned period (control group).

RESULTS

Twenty-one cases of meningitis by Hib were observed in the study group. Twelve children who, as a consequence of their age, had only been vaccinated once or not at all; 7 children were not vaccinated for several reasons. In addition one patient was infected by H. influenzae type f strain and one by a non-typable strain. In the control group 185 cases of Hib meningitis occurred.

CONCLUSION

Hib meningitis was not observed among infants who had been vaccinated at least twice.