Neutralizing Antibodies Against Poliovirus Serotypes Among Children in Southwest Nigeria

ABSTRACT

In May 1988, the World Health bmbly resolved to eradicate poliomyelitis g1,obally by the year 2000. hpite the reported sm in national immunization days, acute flaccid psrdysis surveillance and accelerated efforts to meet the deadline including 'moppingup' were executed in 1999 and subsequent years. Nigeria remains one of the major resemirs for wild poliovirus transmission. Neutralbug antibody lilm? to the three poliovirus sem was determined among children from difierent wmmunities in southwet of Nigeria, and anslysed by age, gdw and location. About 0.5-2 ml of Mood mpIe was colleEted by mwpn&we from each child. Aliqwt of wum from each Mood sample was inactivated prior to neutrhtio1t test by the beta method for pliopirus antibodies. A total of 347 (59.6 per cent) out of 500 d 82 children emoM for the study had at kt mfibody iilm of 1:8 again%! each of the three poII0dt-m mtyp. lmmnnity lmd to the lhthree poliovim senrtyp inweased witb age atid peaked in children aged 44 years. Seven (53.8 per &) mt of 13 rmvacchted children tested in the study had detecfsbIe nwtralizhtg antibody to the three serotypes. Immunity pattern of P2 > P1 and P3 was observed but no correlation between gender and &body to the pOPinm -@pea The -pptllations had 59.6 per cent herd immnnity for the three poliovims serotypes. In a eomtry with bigh incidence of poliomyelitis this situation leav~ a high number of ma-imm& dddren at the risk of infection with one or more poEm serotypes.