evidence: Another important variable that affects IFR is the extent to which people are vaccinated. As the vaccine rollout has progressed, covid-19 has become less fatal. Likewise, the rise of new covid variants6 has helped reduce covid’s IFR. One non-academic analysis indicated that covid-19’s IFR has now become equal to or less than flu’s (around 0.04%), whereas in mid-2020 covid-19 was 20 times more likely to kill people than the flu.7 [...] Barclay, who sits on various UK government advisory bodies, is less certain that public perception—and the perception of those in charge of mitigating risks—will change. "I think we live with deaths from seasonal flu," she says. "And I think we will live with deaths from covid as well. I don’t think there’s any alternative to that.