Caution needed in using oral polio vaccine beyond the cold chain: Vaccine vial monitors may be unreliable at high temperatures.

Background & objectives: Stabilized live attenuated oral polio vaccine (OPV) is used to immunize children up to the age of five years to prevent poliomyelitis. It is strongly advised that the cold-chain should be maintained until the vaccine is administered. It is assumed, that vaccine vial monitors (VVMs) are reliable at all temperatures. VVMs are tested at 37°C and it is assumed that the labels reach discard point before vaccine potency drops to >0.6 log10. This study was undertaken to see if VVMs were reliable when exposed to high temperatures as can occur in field conditions in India. Methods: Vaccine vials with VVMs were incubated (10 vials for each temperature) in an incubator at different temperatures at 37, 41, 45 and 49.5°C. Time-lapse photographs of the VVMs on vials were taken hourly to look for their discard-point. Results: At 37 and 41°C the VVMs worked well. At 45°C, vaccine potency is known to drop to the discard level within 14 h whereas the VVM discard point was reached at 16 h. At 49.5°C the VVMs reached discard point at 9 h when these should have reached it at 3 h. Conclusion: Absolute reliance cannot be placed on VVM in situation where environmental temperatures are high. Caution is needed when using ‘outside the cold chain’ (OCC) protocols.

Final visual outcome following re exploration of cataracts performed by trainee surgeons in India.

Objective: To investigate the outcome of secondary intraocular lens implantation, compare final visual outcome between different categories of surgeon, and evaluate care provided by teaching hospitals to patients with capsular complications. Materials and Methods: Setting: Teaching hospital. Design: Retrospective study. Subjects were recruited by examination of electronic medical records. All patients operated for corrective surgery following capsular complications during cataract surgery were included. All patient medical records were reviewed, and data were collected for 359 eyes. Main outcome measures: Visual acuity and major complications. All collected data were entered into Microsoft Excel and analyzed by SPSS 17 software using cross tabulation and Chi-squared tests. Results: Surgical intervention made a significant difference to the final visual outcome (P < 0.001). The category of the trainee had a significant effect on the final visual outcome (P = 0.021). Conclusion: Capsular complications during cataract surgery should be surgically treated to improve outcome.