[Yellow fever virus 17D neutralising antibodies in vaccinated Colombian people and unvaccinated ones having immunity against dengue].
OBJECTIVE
Determining the frequency of yellow fever seroprotective antibody neutralising titres (YF-NT >or=1:10) in Colombians vaccinated with the 17 D virus and ascertaining the extent to which YF virus can be neutralised by dengue antibodies.


METHODS
Serum samples were taken from 100 subjects who showed their vaccination record and from 116 residents in municipalities (Norte de Santander) affected by a wild YF outbreak in 2002-2003 who were reported to have been YF vaccinated. Sera from individuals with (n=61) and without (n=16) dengue antibodies who had never been YF vaccinated were included. All the sera were tested by 75 % YF plaque-reduction neutralization test.


RESULTS
YF-NT titres >or=1:10 were founded in 90 % of subjects with vaccination recorded with minors variations in relation to age. In contrast, there was correlation between decrease of seroprotective YF-NT titres frequency and increase of immunization time (r=0.95; p=0.04). In residents in YF endemic area, YF-NT titres >or= 1.10 were founded in 92,6 % adults and 69 % children. YF 17 D virus was neutralized (52-100 %) by dengue sera more efficiently than non-dengue immune sera (p<0.001).


CONCLUSIONS
Individuals immunised with YF vaccine 17 D could not be protected against YF: up to 31% children and 10 % adults. Dengue antibodies inhibited YF virus and its significance in terms of YF protection must be investigated.
Gómez
Sergio Y
SY
Centro de Investigaciones en Enfermedades Tropicales, Universidad Industrial de Santander, Bucaramanga, Colombia. sergioyebrailgm@yahoo.com
Ocazionez
Raquel E
RE
D000293:Adolescent; D000328:Adult; D000368:Aged; D000956:Antigens, Viral / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D003105:Colombia / Q000453:epidemiology; D003715:Dengue / Q000453:epidemiology / Q000276:immunology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D014611:Vaccination / Q000706:statistics & numerical data*; D015004:Yellow Fever / Q000453:epidemiology / Q000276:immunology / Q000517:prevention & control; D022341:Yellow Fever Vaccine / Q000008:administration & dosage* / Q000276:immunology*; D055815:Young Adult
D000956:Antigens, Viral; D022341:Yellow Fever Vaccine