What Does a 95% Effective Vaccine Really Mean?

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If you've received a vaccine that's 95% effective, that does not mean you have a 5% chance of getting sick. That’s just not how the numbers are calculated. So let’s take a closer look at how it does work, why we can’t compare these numbers between different vaccines, and why that’s ok.

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Hosted by: Stefan Chin

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Sources:
https://www.nejm.org/doi/full/10.1056/NEJMoa2034577
https://www.nejm.org/doi/full/10.1056/NEJMoa2035389
https://www.cdc.gov/vaccines/basics/test-approve.html
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2536484/
https://clinicaltrials.gov/ct2/show/NCT04505722
https://www.cdc.gov/coronavirus/2019-ncov/vaccines/different-vaccines/janssen.html
https://www.thelancet.com/article/S1473-3099(20)30773-8/fulltext
https://www.cnbc.com/2021/02/28/fauci-all-three-covid-vaccines-highly-effective-urges-people-to-take-available-shot.html
https://www.nytimes.com/2021/01/29/health/Covid-vaccine-explainer.html
https://www.cdc.gov/coronavirus/2019-ncov/vaccines/effectiveness.html
https://www.nature.com/articles/s41591-021-01230-y

Images:
https://www.istockphoto.com/photo/covid-19-coronavirus-vaccine-vials-in-a-row-macro-close-up-gm1253358164-366005110
https://www.istockphoto.com/photo/irus-covid-19-vaccine-bottle-sars-cov-2-vaccine-batch-3d-rendering-4k-gm1250100089-364498780
https://www.istockphoto.com/photo/pattern-of-vaccine-bottles-against-covid-19-with-injection-fluid-3d-ilustration-gm1293494686-387884983
https://www.istockphoto.com/photo/team-of-medical-staff-in-personal-protective-equipment-walking-in-hospital-corridor-gm1221364621-357980003
https://www.istockphoto.com/photo/a-medical-hand-in-a-glove-holds-an-ampoule-with-a-vaccine-and-a-syringe-with-gm1216812369-354959657