ABSTRACT
To provide a basis for further optimization of the polio sequential immunization schedule, this study evaluated the effectiveness of booster immunization with one dose of bivalent oral poliovirus vaccine (bOPV) at 48 months of age after different primary polio immunization schedules. At 48 months of age, one dose of bOPV was administered, and their poliovirus types 1-3 (PV1, PV2, and PV3, respectively)-specific neutralizing antibody levels were determined. Participants found to be negative for any type of PV-specific neutralizing antibody at 24, 36, or 48 months of age were re-vaccinated with inactivated polio vaccine (IPV). The 439 subjects who received a bOPV booster immunization at the age of 48 months had lower PV2-specific antibody levels compared with those who received IPV. One dose of IPV during basic polio immunization induced the lowest PV2-specific antibody levels. On the basis of our findings, to ensure that no less than 70% of the vaccinated have protection efficiency, we recommend the following: if basic immunization was conducted with 1IPV + 2bOPV (especially Sabin strain-based IPV), a booster immunization with IPV is recommended at 36 months of age, whereas if basic immunization was conducted with 2IPV + 1bOPV, a booster immunization with IPV is recommended at 48 months of age. A sequential immunization schedule of 2IPV + 1bOPV + 1IPV can not only maintain high levels of antibody against PV1 and PV3 but also increases immunity to PV2 and induces early intestinal mucosal immunity, with relatively good safety. Thus, this may be the best sequential immunization schedule for polio in countries or regions at high risk for polio.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of 2-phenoxyethanol on potency of Sabin inactivated poliomyelitis vaccine (IPV).</p><p><b>METHODS</b>Sabin IPV samples containing 5 mg or 7 mg 2-phenoxyethanol each dosage respectively were placed separately at 4 degrees C, 37 degrees C for 2 days and 7 days. D-antigen contents were tested with ELISA method. Then neutralizing antibodies in mice and guinea pigs were detected. The safety experiment was performed according to unusual toxicity test of China requirement for biological product.</p><p><b>RESULTS</b>After addition of 2-phenoxyethanol, the I, II, and III D-antigen contents of Sabin IPV did not change. The antibody levels in mice and guinea pigs were not different between experimental group and control group. Animals were safe during observation period.</p><p><b>CONCLUSION</b>2-Phenoxyethanol had no effect on potency and safety of Sabin IPV. It can be used as antiseptic for Sabin IPV.</p>
Subject(s)
Animals , Mice , Anti-Infective Agents, Local , Pharmacology , Toxicity , Antigens, Viral , Allergy and Immunology , Body Weight , Chlorocebus aethiops , Drug Stability , Enzyme-Linked Immunosorbent Assay , Ethylene Glycols , Pharmacology , Toxicity , Guinea Pigs , Neutralization Tests , Poliovirus Vaccine, Inactivated , Allergy and Immunology , Toxicity , Vero CellsABSTRACT
The genome of a new SV40 strain(SV-IMB)isolated from a rhesus monkey was completely sequenced and compared with other isolates.The results showed that the whole genome contains 5246bp,and the average identity of SV-IMB was 98.1% as compared to other SV40 isolates.Its regulatory region is composed of a complete enhancer and a defective enhancer.Amino acid changes occurred to some extent in both the large T antigen (T-Ag) and VP1 region.The findings demonstrate that the SV-IMB is a new SV40 isolate.
