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Vaccinating oldest against COVID-19 saves both most lives, most years of life: Study

ANI | Updated: Feb 26, 2021 05:34 IST

New Delhi [India], February 26 (ANI): A recent study by Joshua R. Goldstein, Thomas Cassidy, and Kenneth W. Wachter states that vaccinating the oldest against COVID-19 saves both the most lives and the most years of life.
The study was released by Proceedings of the National Academy of Sciences.
"Researchers report that vaccinating the oldest individuals against COVID-19 not only saves the most lives but, counterintuitively, also saves the most years of remaining life, because COVID-19 mortality increases more rapidly with age than the rate at which remaining life expectancy decreases with age," read the study.
Many competing criteria are under consideration for prioritizing COVID-19 vaccination. Two criteria based on age are demographic: lives saved and years of future life saved. Vaccinating the very old against COVID-19 saves the most lives, but, since older age is accompanied by falling life expectancy, it is widely supposed that these two goals are in conflict. The study shows this to be mistaken.

The age patterns of COVID-19 mortality are such that vaccinating the oldest first saves the most lives and, surprisingly, also maximizes years of remaining life expectancy. The study demonstrates this relationship empirically in the United States, Germany, and South Korea and with mathematical analysis of life tables. Our age-risk results, under usual conditions, also apply to health risks.
Margaret Keenan received the first vaccination against COVID-19 given in the United Kingdom just a week before her 91st birthday (1). In contexts where vaccine allocation is based on age, prioritizing the very old, who have the highest risk of dying, averts the most deaths. But, from the point of view of saving years of remaining life, it seems that it might be better to target younger people, who are less likely to die quickly of another cause if they can be protected from the coronavirus.
Common intuition suggests a trade-off between saving the maximum number of lives and saving the most future life. Such a trade-off is central to philosophical and ethical discussions and epidemiological and public health studies often report both numbers of deaths and numbers of years of life lost (YLL) in quests for balanced health intervention priorities.
The study shows that this intuition about demographic trade-offs is wrong in the case of COVID-19. While it is true that remaining life expectancy declines with age, this decline is overwhelmed by the exponentially increasing risk of death. For COVID-19, it turns out that vaccinating first the oldest old saves the most lives and also the most life left. Early guidelines from the Centers for Disease Control and Prevention list those aged "65+" as one priority group among several. But, even in terms of YLL, the oldest old in this group should be first in line.
Naturally, many complex considerations besides age impinge on vaccination strategies, and the study defers to epidemiologists, ethicists, and experts in health-related sciences for comprehensive studies that include transmission dynamics and other priorities. The study's aim in this report is strictly demographic. The study takes one--narrow but central--aspect of the picture and shows that formal demography can avert one common misunderstanding. (ANI)