Volume 29, Number 2—February 2023
Research
Correlates of Protection, Thresholds of Protection, and Immunobridging among Persons with SARS-CoV-2 Infection
Table
Term | Definition |
---|---|
Protection curve |
The relationship between the measured immune response of a vaccine in a subgroup of persons and the level of protection from symptomatic infection provided by the vaccine in that subgroup compared with placebo group (protection = vaccine efficacy). |
Threshold of protection |
The level of immune response required to provide a specified level of protection (vaccine efficacy) from COVID-19. The 50% protective threshold is commonly reported. |
Fold-of-convalescent scale |
An attempt to compare different assays by normalizing titers to that of convalescing persons in the same assay. Accurate comparison requires convalescing persons to have similar infection histories. |
IU/mL | A neutralization titer (or mean neutralization titer) calibrated to a World Health Organization international standard and reported in IU/mL. |
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