Vaccinating the vulnerable first may be a flawed strategy

摘要

THE vaccine strategy most nations are following - of vaccinating the most vulnerable first rather than those who are likeliest to spread the coronavirus - may be the best way to save lives in the short term. But it is also the strategy with the greatest risk of driving the evolution of variants that can escape vaccine protection, according to a model developed by Julia Gog at the University of Cambridge. "What is the absolutely worst strategy? You vaccinate all of the vulnerable and none of the 'mixers'," Gog said in an online presentation in February. Gog isn't calling for a change in vaccine strategy. But her finding reinforces the importance of keeping case numbers down as vaccines are rolled out. "We've got to get prevalence down, otherwise we're [creating] a real risk of producing an escape variant," she told New Scientist "What you can't do is get halfway through vaccination and allow cases to rise. That would be devastating."