Characterization of a recombinant type 3/type 2 poliovirus isolated from a healthy vaccinee and containing a chimeric capsid protein VP1.
A Sabin 3/Sabin 2/Sabin 3 (S3/2/3) intertypic recombinant poliovirus was isolated from a faecal specimen from a 2-year-old healthy boy approximately 12 weeks after administration of oral poliovirus vaccine. The first recombination junction was in the genomic region encoding the VP1 capsid protein between nucleotide positions 3274 and 3285 (numbering according to Sabin 3) and the second was in the RNA polymerase region (nucleotide positions 6824 and 6825). The recombination had introduced six Sabin 2-derived amino acids into the Sabin 3 capsid environment in the carboxyl terminus of VP1. The complete genome of the recombinant virus differed from corresponding parental Sabin strains at 33 nucleotide positions, nine of them resulting in an amino acid substitution. Four substitutions were in the capsid proteins and five were in the region encoding the non-structural proteins. One amino acid was changed in the antigenic site 2B and two in site 3B. In addition, the whole antigenic site 3A was replaced by Sabin 2-specific amino acids, but the antigenic characteristics of the S3/2/3 did not show type 2-specific features. Neutralizing antibody titres in sera from Finnish children immunized with the inactivated poliovirus vaccine were not lower against the recombinant virus than against Sabin 3. Our results suggest that the chimeric virus was most likely generated by recombination events in the vaccinee, rather than representing progeny of circulating vaccine-derived virus.
Blomqvist
Soile
S
Department of Microbiology, Enterovirus Laboratory, National Public Health Institute (KTL), Mannerheimintie 166, 00300 Helsinki, Finland.
Bruu
Anne-Lise
AL
National Institute of Public Health, Oslo, Norway.
Stenvik
Mirja
M
Department of Microbiology, Enterovirus Laboratory, National Public Health Institute (KTL), Mannerheimintie 166, 00300 Helsinki, Finland.
Hovi
Tapani
T
Department of Microbiology, Enterovirus Laboratory, National Public Health Institute (KTL), Mannerheimintie 166, 00300 Helsinki, Finland.
D019943:Amino Acid Substitution; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000956:Antigens, Viral / Q000032:analysis / Q000235:genetics; D001665:Binding Sites; D036022:Capsid Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics*; D002353:Carrier State / Q000097:blood / Q000821:virology*; D002675:Child, Preschool; D012321:DNA-Directed RNA Polymerases / Q000235:genetics; D005243:Feces / Q000821:virology; D005260:Female; D016679:Genome, Viral; D006801:Humans; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D009664:Norway; D011051:Poliomyelitis / Q000276:immunology; D017955:Poliovirus / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification; D011054:Poliovirus Vaccine, Inactivated / Q000276:immunology; D011055:Poliovirus Vaccine, Oral / Q000235:genetics* / Q000276:immunology; D011995:Recombination, Genetic; D014611:Vaccination; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000378:metabolism
C101758:2B protein, poliovirus; D000914:Antibodies, Viral; D000956:Antigens, Viral; D036022:Capsid Proteins; D011054:Poliovirus Vaccine, Inactivated; D011055:Poliovirus Vaccine, Oral; C442540:VP1 protein, Poliovirus; D017361:Viral Nonstructural Proteins; D012321:DNA-Directed RNA Polymerases