US vaccine rollout was close to optimal at reducing deaths and infections, according to a model comparing 17.5 million alternative approaches

Posted Nov 18, 2021

The Centers for Disease Control and Prevention’s plan for who gets vaccines and in what order saved nearly as many lives and prevented nearly as many infections as a theoretically perfect rollout, according to a new mathematical model developed by Iowa State University researchers to assess the rollout of COVID–19 inoculations in the U.S.

In December 2020, with a limited number of vaccines available, the CDC had to make a hard decision: Who gets the COVID-19 vaccines first? It decided to divide the U.S. population into four groups for vaccine prioritization based on age, occupation, living condition and known COVID-19 risk factors.

Using a new model and an Iowa State University supercomputer, Ph.D. Candidate in Ecology and Statistics Audrey L. McCombs and Assistant Professor of Mathematics Claus Kadelka compared the real–world CDC recommendations with 17.5 million possible strategies that also staggered the rollout in up to four phases. To calculate how well a vaccine allocation strategy performed, their model measured total deaths, cases, infections and years of life lost. They found that the CDC allocation strategy performed exceptionally well – within 4% of perfect – in all four measures.

Read McCombs and Kadelka’s full article in The Conversation here.