A UC Berkeley study published Thursday found that vaccinating elders saves both the most lives and the most years of life.
Vaccine efficacy can be measured in many ways, including the total number of lives saved and total years saved. The study sought to analyze whether vaccinating elders would also save the most years of life.
“It was well known that giving it to old people would save the most lives, but there were questions that it wouldn’t save the most use of future life,” said lead researcher and campus demography professor Joshua Goldstein. “We wanted to see if there was a conflict there.”
The result was unexpected, said Kenneth Wachter, study co-author and campus demography and statistics professor emeritus. While most people expect that vaccinating younger people would save more years, the study found vaccinating elders is often both practically and mathematically the better option.
The study calculated the total years saved by multiplying total lives saved by the average years saved per life. While older populations may have fewer years left, that is overshadowed by the sheer number of older lives saved, according to the study.
From a practical standpoint, the study reaffirms the current policy of prioritizing elder vaccinations in the United States, according to Wachter. He noted the study would also encourage other countries like India, which has not yet decided on a system for prioritizing vaccine distribution, to adopt policies that focus on the elderly.
Goldstein said these results also have implications for other at-risk populations.
“Our paper does have applications to (other health risks). The logic of the paper is, the more at risk you are, the more you should get the vaccine,” Goldstein said. “We now have a baseline model that we can extend.”
Goldstein also highlighted the study’s scientific contributions. He added that one reason why the paper was published was because reviewers were interested in the new insights that the study’s methodology offered for mathematical applications in the field of demographics.
The researchers, however, also noted the study’s limitations.
“Saving lives and saving years of life is only one criteria,” Wachter said. “We are not saying that this is more important than other effects.”
The study also poses a serious philosophical quandary in that it implies some lives are worth more than others, according to Goldstein. While the study’s use of mathematics allowed the researchers to temporarily sidestep this problem, Goldstein admitted ethical questions still remain.
The researchers plan to continue analyzing this issue.
“There have been many simulations that have looked at that, but we’re trying to look at it from an abstract way. We’re hoping this will clear up what drives the simulation models,” Goldstein said. “The next paper is not about this trade-off between lives lost and life left, but rather it’s about optimal vaccine policy and the consequences of departing from optimality.”