Prognosis
Omicron Gets Around Previous Covid Infection, Study Warns
- Booster dose lifts protection dramatically, research finds
- No evidence in study that omicron less severe than delta
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A previous Covid-19 recovery provides little shield against infection with the omicron variant, a research team from Imperial College London showed in a large study that underlines the importance of booster shots.
Having had Covid probably only offers 19% protection against omicron, the study showed on Friday. That was roughly in line with two doses of vaccine, which the team estimated were as much as 20% effective against omicron. Adding a booster dose helped dramatically, blocking an estimated 55% to 80% of symptomatic cases.