Increased female-male mortality ratio associated with inactivated polio and diphtheria-tetanus-pertussis vaccines: Observations from vaccination trials in Guinea-Bissau.
BACKGROUND
The 2-fold increase in female mortality after high-titer measles vaccine may have occurred because many children received diphtheria-tetanus-pertussis (DTP) vaccine or inactivated polio vaccine (IPV) after high-titer measles vaccine.


OBJECTIVE
We examined whether DTP vaccine and IPV were associated with increased female mortality when they were the most recent vaccine administered to children who had not received measles vaccine.


METHODS
IPV was used as a control vaccine in 4 randomized trials of early measles vaccination (MV) with enrollment at 4-6 months of age conducted in Guinea-Bissau. Many children had not received all 3 DTP vaccinations before enrollment, and therefore received DTP after IPV or MV. We examined whether DTP vaccination status at enrollment affected the female-male mortality ratio.


METHODS
9544 children enrolled in 4 trials.


METHODS
The female-male mortality ratio in different vaccine groups.


RESULTS
Females had a higher mortality rate than males among children randomized to receive IPV (mortality rate ratio [MR] 1.52, 95% CI 1.02-2.28), but females had a similar mortality rate to males among children randomized to receive MV (MR 1.01, 0.69-1.46) and among children in the IPV group after they had received MV at 9 months of age or later (MR 0.88, 0.68-1.14). Children who had not received a third dose of DTP before enrollment (and were likely to receive DTP after MV or IPV) tended to have a higher mortality than children who had received all 3 doses of DTP (MR 1.30, 0.97-1.73). This effect was seen only among girls (MR 1.61, 1.08-2.40) and not among boys (MR 1.02, 0.67-1.54). Girls had a lower mortality when MV was the most recent vaccine received rather than DTP or IPV (MR 0.49, 0.28-0.87).


CONCLUSIONS
Randomization to IPV was associated with higher female than male mortality. However, the increased female mortality might result from additional doses of DTP received after enrollment and before measles vaccination.
Aaby
Peter
P
Projecto de Saúde de Bandim, Indepth Network, Bissau, Guinea-Bissau. P.aaby@bandim.org
Garly
May-Lill
ML
Nielsen
Jens
J
Ravn
Henrik
H
Martins
Cesario
C
Balé
Carlitos
C
Rodrigues
Amabelia
A
Benn
Christine Stabell
CS
Lisse
Ida Maria
IM
D046688:Child Mortality; D002675:Child, Preschool; D015721:Diphtheria-Tetanus-Pertussis Vaccine / Q000008:administration & dosage* / Q000009:adverse effects* / Q000276:immunology; D005260:Female; D006169:Guinea-Bissau / Q000453:epidemiology; D006801:Humans; D007115:Immunization Schedule; D008297:Male; D008458:Measles Vaccine / Q000009:adverse effects / Q000276:immunology; D011054:Poliovirus Vaccine, Inactivated / Q000008:administration & dosage* / Q000009:adverse effects* / Q000276:immunology; D012727:Sex Characteristics
D015721:Diphtheria-Tetanus-Pertussis Vaccine; D008458:Measles Vaccine; D011054:Poliovirus Vaccine, Inactivated