A Sabin vaccine-derived field isolate of poliovirus type 1 displaying aberrant phenotypic and genetic features, including a deletion in antigenic site 1.

Abstract

Poliovirus strains derived from the oral poliovirus vaccine (Sabin) can be differentiated from wildtype poliovirus by tests based on either immunological or genetic properties of the strains. The characterization of a recently identified poliovirus type 1 isolate with exceptional properties is described. Initial phenotypic analysis of the virus by use of polyclonal absorbed antisera suggested a wild-type character. However, the different genomic analyses all confirmed the Sabin-derived character of the virus. All 17 plaques isolated from the strain shared these properties, thus excluding the possibility of a mixture of a wild-type and a Sabin-derived strain. To elucidate the properties of this virus further, the nucleotide sequences of the P1 region and most of the 5h noncoding region were established. Although the nucleotide identity with Sabin 1 was more than 99n4 %, mutations were observed in regions encoding three major antigenic sites ; the deduced amino acid substitutions confirmed the aberrant results of micro-neutralization assays with sitespecific monoclonal antibodies. The most striking feature was the existence of a hexanucleotide deletion in the VP1 gene, which gave rise to a two amino acid deletion in the BC loop. In spite of these antigenic changes, the strain was readily serotyped as poliovirus type 1 under standard conditions. Likewise, replication of the virus under cell culture conditions was not affected by these mutations or by the deletion. Standard polio vaccination protects against this aberrant virus, and its epidemiological significance remains open.

Circulation of Type 1 Vaccine-Derived Poliovirus in the Philippines in 2001

“…; data not shown) might be responsible for the altered neutralization antigenicity of the cVDPV isolates. Such amino acid changes have frequently been found in many Sabin 1-derived polioviruses isolated from OPV recipients, vaccine-associated paralytic poliomyelitis patients, and the environment (18,39,43).…”

Hepatitis A Virus Mutant Spectra under the Selective Pressure of Monoclonal Antibodies: Codon Usage Constraints Limit Capsid Variability

“…In the case of VP3, 22% of the deleted residues are located on the capsid surface, also including residues involved in the antigenic structure. Deletion mutants affecting antigenic sites have been described for other picornaviruses such as poliovirus (27) and even HAV (9,10).…”

Changes in Population Dynamics during Long-Term Evolution of Sabin Type 1 Poliovirus in an Immunodeficient Patient

“…Three of the four known antigenic sites varied over the course of the virus excretion period, including a deletion of 2 amino acids (residues 101 and 102 in VP1) in antigenic site 1 in one lineage. A similar virus, in which residues 102 and 103 were deleted, was isolated from a suspected polio case in Turkey in 1997 (54). Changes were observed throughout the period of infection up to the last isolate.…”