title: Monitoring the stability of human vaccines.
abstract: Postmarketing stability studies of vaccines that tend to be close to their clinical specification at the end of the expiration dating period may require enhanced annual monitoring. In addition, an early assessment of product stability prior to completion of each individual study is desired. However, predictive measures of individual lots may produce early indication of failure. In many cases, these prove to be false alarms. For such products, continued product quality after marketing should, therefore, depend less on evaluating individual observations or individual lot projections, and more on assuring that the underlying stability profile of the product as a whole has not changed. We propose a monitoring procedure and an index of the average quality of vaccine lots currently on the market. We explore the statistical properties of the index for several experimental designs for sampling of marketed lots, and we describe an optimality property of the index.
authors.affiliation: Flower Valley Consulting Inc., Rockville, Maryland 20853, USA. fairweather@flowervalleyconsulting.com
authors.forename: William R
authors.initials: WR
authors.lastname: Fairweather
authors.forename: Robin
authors.initials: R
authors.lastname: Mogg
authors.forename: Philip S
authors.initials: PS
authors.lastname: Bennett
authors.forename: Jinglin
authors.initials: J
authors.lastname: Zhong
authors.forename: Cynthia
authors.initials: C
authors.lastname: Morrisey
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Schofield
mesh_terms: D004355:Drug Stability; D006801:Humans; D015233:Models, Statistical; D011358:Product Surveillance, Postmarketing / Q000592:standards / Q000706:statistics & numerical data*; D011786:Quality Control; D013997:Time Factors; D014612:Vaccines / Q000592:standards*
chemical_list: D014612:Vaccines