Recombinant Poliovirus circulation among healthy children immunized with oral polio vaccine in Abidjan

Abstract

In order to assess the level of polio virus with natural recombinant genome and wild polio virus circulating in the environment of healthy children aged 0 to 5 years in Abidjan, 130 polio viruses made up of 26 polio type 1, 55 type 2 and 49 type 3 were identified by neutralisation test with monoclonal antibodies and restriction fragment length polymorphism (RFLP) targeting the VP1 and 3D1 gene. Four wild non Sabin-like (NSL) strains (3.1%): one type 2 and three type 3 were identified in non vaccinated children. One hundred and six (81.5%) isolates were Sabin-like, 20 (15.4%) were recombinant with the following polio virus profiles: 2 Sabin-like type 1/type 2, 3 Sabin-like type 3/type 1, 11 Sabin-like type 3/type 2 and one polio virus type 3 NSL/Sabin-like type 3. Intertypic vaccine/vaccine or vaccine/wild strain recombinant polio virus circulating among healthy children rate was high and suggested the need for a molecular surveillance of vaccine strains. Oral Polio Vaccine (OPV) strains are well-known to revert to pathogenicity in vaccines. Therefore, the long term excretion of pathogenic OPV derived strains by some vaccinees needs to be considered quite seriously. It therefore suggested that all polio virus isolated from acute flaccid paralysis (AFP) be analyzed by restriction fragment length polymorphism and sequencing of the viral genome.


Key words: polio virus, recombinant virus, healthy children, Cote d'Ivoire.


African Journal of Biotechnology Vol.3(5) 2004: 289-293