Læknablaðið : fylgirit - 01.08.2002, Blaðsíða 25

ABSTRACTS / 2 1 ST
NORDIC CONGRESS OF ALLERGOLOGY
the 2nd 19F-TT immunization or 3 hours after passive immunization
with infant sera, the mice were challenged intranasally with Strepto-
coccus pneumoniae of serotype 19F or 19A and protection against
lung infection evaluated by counting colony forming units (CFU).
Immunization with 19F-TT induced significant IgG antibodies to
both 19F and 19A, and reduced the number of CFU in lungs
compared to unimmunized mice. In infants vaccinated with the 11-
valent PNC, IgG anti-19F were significantly higher than IgG anti-
19A, and there was a correlation between IgG 19F- and 19A-
antibodies. Passive immunization of mice with infant sera reduced
the number of 19F CFU in the lungs. A significant correlation was
found between the number of 19F CFU and 19F-specific IgG titers
in both infant and murine serum samples. Passive immunization
with infant sera also reduced the number of 19A CFU in the lungs
significantly compared to unimmunized mice. We conclude that
immunization with tetanus-conjugated pneumococcal polysaccha-
ride vaccine induces protective 19F-specific antibodies, which may
cross-react and protect against serotype 19A infections.
P 15 - Nasopharyngeal (NP) carriage of vaccine
serotype pneumococci is more common in children
who respond poorly to the 11-valent pneumococcal
conjugate (Pnc)
Sigurðardóttir SÞ', Kristinsson KG', Ingólfsdóttir G', Guðnason Þ',
Davíðsdóttir K;, Kjartansson S', Yaich M’, Jónsdóttir I'
'Landspítali University Hospital and 2Centre for Child Health Services, Reykjavík,
Iceland, 'Aventis Pasteur, Lyon, France.
We have previously reported equal safety and immunogenicity of
two 11-valent Pnc formulations. Here we compare the serotype-
specific IgG response in children carrying vaccine serotypes (VT) in
the nasopharynx to that in children with no positive culture for the
serotype in question.
Methods: 146 Icelandic infants received Pnc at 3,4,6 and 13 mo. NP
samples were cultured at 4, 7,10,14,18 and 24 mo. Antibodies to
VT were measured by ELISA at 3, 7, 13, 14 and 24 mo. Un-
vaccinated controls of 105 children, matched for age and day-care
centre, were recruited at 24 mo for NP culturing and pneumococcal
antibody measurements.
Results: Of the 146 vaccinated infants, 14, 20 and 29 infants,
respectively, had positive NP cultures for Pnc serotypes 6B, 19F and
23F, at least once between 4 and 24 mo. These infants had lower
post-primary and post-booster vaccination IgG (mg/ml GMC)
compared to the vaccinated infants with negative NP cultures at
each visit (t-test). Vaccinees had higher GMC-IgG levels to the
vaccine serotypes at 24 mo of age compared to the controls but at
that time no difference was observed in NP carriage of pneumo-
cocci.
Conclusion: Infants who responded poorly to the Pnc conjugate
vaccine were more often colonized with vaccine serotypes indica-
ting mucosal protection of serotype-specific IgG. Prevention of NP
colonization or eradication of NP pathogens may to some extent
depend on IgG concentration in serum. An effective pneumococcal
conjugate vaccine may decrease NP colonization of pneumococci
and therefore decrease pneumococcal disease.
P 16 - Prevalence of Atopy and Atopic diseases
in lcelandic Schoolchildren
Clausen M1, Björkstén B2, Haraldsson Á', Kristjánsson S'
'Landspítali University Hospital, Reykjavík, Iceland; 2Center for Allergy
Research, Karolinska Institute, Stockholm, Sweden
Background: The prevalence of adult atopic diseases in Iceland is
lower than in Western Europe but there are no data concerning
children.
Objective: To investigate the prevalence of atopic diseases and
sensitivity to common allergens, in 10-11 year old schoolchildren as
part of the phase-2 of the International Study of Asthma and
Ailergy in Children (ISAAC).
Methods: 946 children answered a questionnaire about atopic
diseases. Skin prick tests (SPT) with 6 allergens were performed on
775 children and they were also examined for signs of atopic eczema.
Results: The prevalence of allergic rhinitis was 11% and asthma
9%. The reported prevalence to eczema was 26.9%, but only 10.3%
had signs when inspected. A positive SPT was recorded in 24.9%
of the children, i.e. 18.7% to grasses, 12.9% to cat, 3.6 to trees, 2.9%
to D. pter, 1.4% to D. farinae and 0.5% to alternaria.
Conclusion: The high prevalence of atopic diseases in children at
10-11 years is surprising as the prevalence in adults is very low in
Iceland. The findings resemble those in developing countries. Other
changes in environmental factors would be operative, however, as
Iceland has had an affluent lifestyle for a considerable time. The
high prevalence of sensitivity to grass pollen may be explained by
the long grass pollen season and low exposure to other allergens on
the island.
Læknablaðið/Fylgirit 46 2002/88 25