We’re starting to see news outlets say there is an alarming trend where vaccinated people are getting COVID-19 (such as this one from the WSJ). This is an example of base rate fallacy—in a population with a high vaccination rate it is inevitable that new cases include vaccinated people (especially in a country like Israel with extremely high vaccination rate). We should not take that to mean vaccines are suddenly ineffective (they’re not).
Links to this note
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Breakthrough COVID-19 Cases Are 74% Adults 65 or Older
CDC data shows that 74 percent of breakthrough COVID-19 cases are among adults 65 or older and make up the vast majority of vaccinated people that are hospitalized.
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COVID-19 Vaccine Is 33 Percent Effective Against Omicron
A study of 211,000 COVID-19 cases and 78,000 Omicron variant cases found that the vaccine is only 33% effective at preventing infection by 70% effective at preventing hospitalization.