RESUMEN
@#Objective To determine the cetrimonium bromide(CTAB)residue in polysaccharide vaccines using ultra performance liquid chromatography-mass spectrometry(UPLC/MS-MS),and analyze and evaluate the uncertainty of the determination results.Methods By establishing a mathematical model,the sources and values of uncertainty introduced in the measurement process were analyzed,the uncertainty components of each influencing factor were calculated,and the standard uncertainty and expanded uncertainty were synthesized to form an uncertainty report.Results At 95% confidence interval,the expanded uncertainty was 0. 002 8 mg/kg. The determination result of CTAB residue in polysaccharide vaccine was reported as(1. 000 6 ± 0. 002 8)mg/kg(k = 2,confidence interval p = 95%).Conclusion The main factors affecting the accuracy of determination results are the preparation of standard solution and the introduction of recovery rate,which should be focused on and controlled in the experiment process to make the detection results more reliable.
RESUMEN
The low- and middle-income countries bear the highest burden of typhoid fever in the world. India, along with other South Asian countries, has a significant incidence of typhoid fever among young children though there is a paucity of published data on community burden. In spite of the availability of Vi-polysaccharide (Vi-PS) and conjugated Vi-PS vaccines, these are not adequately utilized in India and in the neighbouring countries. To address many shortcomings of the unconjugated Vi-PS vaccines, typhoid conjugate vaccines (TCVs) are developed by conjugating Vi-PS with different carrier proteins. Three such vaccines using tetanus toxoid as a carrier protein are already licensed in India. Several other Vi-PS conjugates are currently in various stages of development. The current review provides an update on the existing and upcoming new TCVs along with a detailed discussion on the various issues involved with their clinical use and limitations.