Haemophilus influenzae Type B conjugate vaccine introduction in Mali: impact on disease burden and serologic correlate of protection.
In Bamako, Mali, where surveillance revealed a high incidence of Haemophilus influenzae type b (Hib) invasive disease, Hib conjugate vaccine was introduced into the Expanded Program on Immunization and the impact assessed. Annual confirmed Hib hospitalizations for infants 0-11 months of age fell from 175/10(5) to 44/10(5) (P < 0.001); among infants 6-7 months of age Hib hospitalizations fell from 377/10(5) to 69/10(5), (82% decrease, P < 0.001). Invasive Streptococcus pneumoniae hospitalizations remained unchanged. In a baseline serosurvey, only 3/200 infants 6-7 months of age (1.5%) had protective anti-polyribosylribitol phosphate (PRP) titers > or = 0.15 microg/mL and 1(0.5%) had >or = 1.0 microg/mL. In serosurveys 18 and 30 months after vaccine introduction, 168/201 (84%) and 184/200 (92%) infants, respectively, had titers > or = 0.15 microg/mL and 141/201 (70%) and 163/200 (82%) had titers > or = 1.0 microg/mL. Introduction of Hib vaccine led to rises in anti-PRP seroprevalence, significant reductions in Hib disease, and all-cause hospitalizations, whereas S. pneumoniae disease remained unchanged.
Sow
Samba O
SO
Centre pour le Développement des Vaccins, Mali (CVD-Mali), Bamako, Mali.
Tapia
Milagritos D
MD
Diallo
Souleymane
S
Keita
Mamadou Marouf
MM
Sylla
Mariam
M
Onwuchekwa
Uma
U
Pasetti
Marcela F
MF
Kotloff
Karen L
KL
Levine
Myron M
MM
D000907:Antibodies, Bacterial / Q000097:blood; D016667:Bacterial Capsules / Q000276:immunology*; D006192:Haemophilus Infections / Q000097:blood / Q000453:epidemiology* / Q000517:prevention & control*; D018073:Haemophilus Vaccines / Q000276:immunology*; D019741:Haemophilus influenzae type b / Q000276:immunology*; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008302:Mali / Q000453:epidemiology; D009313:National Health Programs; D011008:Pneumococcal Infections / Q000453:epidemiology; D015995:Prevalence; D016036:Seroepidemiologic Studies; D012698:Serologic Tests; D018074:Vaccines, Conjugate / Q000276:immunology
D000907:Antibodies, Bacterial; D018073:Haemophilus Vaccines; C044237:Haemophilus influenzae type b polysaccharide vaccine; D018074:Vaccines, Conjugate