Monitoring the infectious titer of bOPV and the vaccine vial monitor stage at different storage temperature ranges

/0.1 mL), and VVM was rated at 0% degradation. At 2-4°C, 100% of the vaccine samples sustained potency for 6 months, and the color of VVM remained at 0% degradation after 3 months, but 10%, 20%, 20% after 4, 5, and 6 months, respectively. At 27-29°C, all the vaccine samples sustained potency at 1 week, 50% after 2 weeks, and their VVM were rated 10%, 20%, 40% and 100% after 1, 2, 3, and 4 weeks, respectively. The potency of the 50% of vaccine samples stored at 35-36°C remained stable for a week, with their VVM rated 10%, 50%, and 100% after storage for 1, 2, and 3 weeks, respectively. At atmospheric temperatures (22-44°C), the titers of all the vaccine samples dropped significantly, and VVM attained 100% degradation within a week. The potency of the bOPV was preserved under refrigeration for 6 months, at room temperature for 2 weeks, and at an incubator for a week and severely degraded at atmospheric temperatures within a week.