In order to determine antibody levels against Streptococcus
pneumoniae (pneumococcus) and
Haemophilus influenzae type b (Hib) in a population of splenectomized
subjects, 561 persons in
a Danish county, splenectomized between 1984 and 1993 were identified.
Two
hundred and thirty-five were alive and 149 participated in the study. Each
person
donated a blood sample
for antibody determination by ELISA. Though vaccine coverage among the
149
persons was
91% only 52% had ‘protective’ levels of pneumococcal antibodies.
Despite recommendations
for regular follow-up on pneumococcal antibody levels this had only been
carried out in 4% of
the subjects. Splenectomized subjects who needed pneumococcal revaccination
were significantly
more likely to have received their initial vaccination less than 14 days
before or after
splenectomy, as recommended, than those not requiring revaccination. Therefore,
the timing of initial pneumococcal vaccination in relation to splenectomy
seems to be
important. All persons
had Hib antibody levels higher than 0·15 μg/ml and 60% had
levels higher than 1 μg/ml,
which are the levels thought to provide short term and long term protection,
respectively. In total, 37% of the 149 persons tested had pneumococcal
and Hib antibody
levels thought to correlate with protection from serious infections.