Very curious as to how this was determined: "Although two doses of the vaccine may still offer protection against severe disease caused by the Omicron strain,

Very curious as to how this was determined: "Although two doses of the vaccine may still offer protection against severe disease caused by the Omicron strain, it’s clear from these preliminary data that protection is improved with a third dose of our vaccine" Based on the latest data, not a single person has died from Omicron, so what are they using to back this up? It's possible that Omicron is less deadly than previous strains, so what they're claiming may be kinda like saying "our water is wetter"...