 This study examined the prevalence of intact proviruses in patients on antiretroviral therapy, ART, as well as their decay rates over time. The researchers used two methods, one which measured the amount of intact provirus present in the sample, and another which measured the amount of virus that was fully replicative. They found that both methods agreed on the overall prevalence of intact provirus, but differed in terms of the rate at which they decayed. This suggests that there may be some long-lived intact proviruses that are not detected by the first method, or that some defective proviruses may have been misclassified as intact. The researchers then developed a mathematical model to explain these differences, and concluded that combining both methods would provide a more accurate estimate of the decay rate of intact provirus. This article was authored by Daniel B Reeves, Christian Gabela, Thiago Y. Oliveira, and others.